SlideShare ist ein Scribd-Unternehmen logo
1 von 66
Downloaden Sie, um offline zu lesen
Comparison of time-domain Sparameters of RG58 cable
computed by: Theory, CST,
SPICE, DWS
S. Caniggia, P. Belforte
February 04, 2014

1
Outline
•
•
•
•
•
•
•
•
•

Introduction
S-parameter definition in time domain
Simulations of a 18.3-cm RG58 coaxial cable
S11&S21 computed by analytic approach (theory)
Cable Studio 2013 results as source of a BTM of a 1.83m RG58 coaxial cable used in DWS
Analytical method results as source of a BTM of a 10-m
RG58 coaxial cable used in DWS
Conclusions
Appendix: Dielectric losses (Tanδ)
References
2
Introduction
•
•
•
•

•

•

In this report, the sixth of a series devoted to lossy lines [1,2,3,7,8],
several approaches for computing time-domain step responses of a
lossy line are outlined and compared.
The methods used are: MWS of CST, CS of CST, RL-TL model for
SPICE & DWS, Theory.
The purpose is to pinpoint the advantages and drawbacks of each
approach for simulating lossy lines.
The feasibility of deriving BTM models to be used by DWS is
analyzed. Long lossy lines can be simulated by DWS in seconds
using a cascade of shorter line segment characterized as Behavior
Transmission Model (BTM) by parameters S11 & S21 in time
domain (7,9).
These S parameters can be computed by CS or theory and can be
used as models for DWS. If a piecewise linear (pwl) approximation
is used for behaviors, a dramatic speedup of simulations can be
obtained
A typical RG58 coaxial cable is used as line sample for the study.
Methods for time domain simulations of lossy lines [4]
Three methods can be used to simulate lossy lines in transient. The choice depends
on which simulator should be used for a simple or complex line structure.
1.
Behavioral Transmission line Model (BTM) block, based on time-domain step
responses of lossy line S-parameter to be used within the Digital Wave
Simulator (DWS) [1,2,3,7,8,9] to get quick simulations.
2.
Vector fitting technique (VFT) [4,6] to set, starting from analytical expression
of losses, an equivalent circuit for a cascade of RLGC-TL (lossless) segments of
line electrically short to be used with a SPICE-like circuit simulator such as
MC10 [1,2,3,4,6] or DWS for faster (1-2 order of magnitude) simulations
[1,2,3,7,8] .
3.
Model Order Reduction (MOR) technique to set, starting from S parameters,
an equivalent circuit of the line (complex net of RLGC-TL) for the frequency
range of interest to be used by CST circuit simulator [1,2,3,7,9].
Note:
•
The lossy line can be both a cable or a PCB trace.
•
VTF and MOR should be used for the frequency range of interest.
•
CST is particularly suitable for complex line structures such as multi-conductor
lines with shields.
•
DWS allows the use of hybrid BTM and circuital models [8]
Flow chart for direct transient simulation of lossy lines by using
three different methods: SPICE, CST, DWS [4].
Define the line (a,p,σ,μ,Rdc,tanθ,Kp) and compute the per-unit-line parameters: Zi, L0, C0, Gd
unit cell
RL

TL

Segmented line

Full line

Which
model ?

GC

One block: measured or
computed S-parameter line in
time domain
S11

One block
complex RLGC-TL net

Zi, L0,C0, Gd
VFT technique

Modeling
Cascade of unit cells to
form a block (SPICE-like
Sim.)

MOR technique

S21

Which
technique?

S technique

Modeling

Modeling

One RLGC-TL block

One BTM block
(DWS)

(SPICE in CST)

Cable block in schematic
Simulated waveforms with several loadings
(passive/active, linear/non-linear)
S-parameter definition in time
domain

6
S-parameter definition for two-port network [5]
I1

a1

I2
+

+

Z01

b1

V1

Two port network

-

V2
-

a2
b2

Z02

With n=1,2:
Normalized
incident wave

Vn 
an 
Z0n

Vn  (Vn   Vn - )  Z0n (a n  b n )
1
1
In 
(Vn   Vn - ) 
(a n  b n )
Z0n
Z0n

Vn 
bn 
Z0n

Normalized
reflected wave

 b1  S11 S12   a1 
b   S
S22  a 2 
 2   21
 

7
S-parameter physical interpretation [5]
a1

a2=0

Z01

+
Source applied
to Port 1
-

b1  S11a1
b 2  S21a1
a1 

Port 2 matched

Two port network

b1

Z02

b2

S11 is just the input reflection coefficient when the
output is matched.
S21 is the ratio of waves to the right at output and input
under this condition.

V1  Z01I1
2 Z01

V1  Z01I1
b1 
2 Z01

When Z01=Z02=Z0 (the characteristic impedance of the two port network
representing a cable), and the source is a step of amplitude 2V: 1+S11 and S21
are the V1 and V2 voltages respectively.

8
Port signals in MWS
•
•
•
•

MWS stimulates the network by means of a gaussian pulse having
a flat bandwidth up to the maximum frequency defined by the user.
Port signals: (i1), (o1,1), (o2,1) of MWS have the meaning
respectively of incident (a1), reflected wave at port1 (b1) and
reflected wave at port2 (b2).
Better results can be obtained by using waveguide ports instead of
discrete ports when possible: less oscillations in reflected wave b1.
To find equivalent circuit of a DUT it is better to use the option in
MWS “S parameters without normalization to fixed impedance”
instead of “…with…”: resonance peaks are avoided. These
resonances are due to mismatch between port and waveguide
which could be: coaxial cable, microstrip, etc.

•

Integrating (o1,1) & (o2,1) waveforms in time domain, we get the
response at port1 (1+S11) and port2 (S21) of a step pulse with rise
time tr determined by the maximum frequency.

•

The source pulse is obtained by integrating (i1) of MWS.
9
S parameters in time domain
Typical source and load voltage waveforms for an interconnect matched
at both ends: lossless TL (dashed line), frequency-dependent lossy TL
(solid line) [6, Fig.7.3]

Definitions of S
parameters in time
domain:
•VS=1+S11

•VL=S21

When TL has characteristic impedance different from the loads, distortions occur
10
Simulations of a 18.3-cm RG58
coaxial cable

11
S-parameters calculations

•
•
•

•
•
•

Time-domain S-parameters computation from incident and reflected
waves provided by MWS is shown.
S11 and S21 time-domain step responses with matched line at both
ends are computed integrating the waveforms provided by MWS
when using waveguide ports.
Comparison with RL-TL model used by MC10 (SPICE) or DWS
[1,2,3] and 2D-TL model of Cable Studio (CS) [3] is given.
CS 2013 takes into account also proximity effects [3].
The accuracy of models has been evaluated by comparison with
actual TDR measurements of a 1.83-m RG58 coaxial cable [2,3,7,8].
The lack of dielectric losses in the RL-TL model is somewhat
compensated by the overestimation of skin effect [3].

12
MWS structure
•Frequency range: 0-40GHz
•Waveguide ports
Cable parameters:
• Dielectric=2.3, tangent delta=0
• Lossy metal: 5.8e7 S/m
• Geometry in mm: length=183; wire
radius=0.395, shield radius=1.397; shield
thickness=0.127
Meshcells=545,472

13
Input signal in MWS

Gaussian (40GHz)

Step source

Integration of
gaussian
normalized to
maximum value
of the integral

Tr=23ps

14

Rise time tr between 10-90% is about 23ps as used in TDR measurements
Port signals of RG58 in MWS

i1

o21

ns

o11

ns

Integrating o11
and o21 and
normalizing the
results to the
maximum value
of the gaussian
integral, we get
respectively S11
and S21 as
response of a
step with tr=23 ps

15
Cable studio (CS) structure

Step source with 40GHz
bandwidth imported from
MWS (see previuos slide)
Ohmic losses only

16
MC10 (SPICE) structure
The equivalent RL circuit was
obtained by VFT applied to
compact expressions for
coaxial cable without factor ½,
see Eq.7.57 of [6]

Step source
with tr=25ps

S11=VTin
S21=VTout

Cascade of 100 1.83-mm unit RL-TL cell

17
DWS (Spicy SWAN [12 ]) circuits

RL-TL5mmx37=185mm

185-mm RG58 from CST

18
Input (1+S11) and output (S21) line waveforms
Line length= 18.3 cm

1+S11

S21

MWS
waveforms

ps

Remark: MC10 and CS provide similar waveforms
19
S11
Volt
MC10&DWS

MWS: solid
CS: dot

MWS&CS

MC10: dash

ps

• MC10 & DWS with RL-TL cells compute the
same waveforms [10]
• MWS & CS provide about similar waveforms
with less losses (lower values than DWS & MC10)

20
1+S11 and S21
Volt
1+S11

MC10

MWS: solid
MWS&CS

CS: dot

MC10: dash

MWS&CS

MC10
S21

DWS

1+S11

ps

• MC10 & DWS compute the
same waveforms [10]
• MWS & CS compute similar
waveforms with about half losses

S21

• S11 of CS & DWS show some
slight segmentation due to 37cell discretization
21
1+S11 and S21 with and without dielectric
losses
MC10
CS

CS

MC10

•Solid MC10 RLTL without dielectric losses
•Dash CS 2013 without dielectric losses

•Dot CS 2013 with dielectric losses (Tanδ=0.8m)
Dielectric losses introduce just a slight difference in this
portion of the waveform

22
CS 2012: Adding dielectric losses
(tanδ=0.8m)
Volt

Ohmic losses
1+S11

S21

sec

Volt

Ohmic + dielectric losses

1+S11

S21

sec

•There are slight
differences in this
portion of the
waveform

•The
segmentation
effect is
eliminated 23
CS 2013: Adding dielectric losses
(tanδ=0.8m)
Volt

Ohmic losses
1+S11

S21

sec

Volt

Ohmic + dielectric losses

1+S11

•The
segmentation
effect is
eliminated also
for ohmic losses
• There is a slight
increase of losses
due to proximity
effect in CST
2013 vs 2012

S21
sec

24
Input and output line voltages
VS
VL
MC10

VS
VL
MWS 2013

VS

VL
CS 2013

•For MC10 a ramp has
been used

•For MWS and CS the
time integral of a
gaussian (40GHz BW)
has been used.
• S11 (=Vin-1) and S21 (=Vout)
should be computed with an input
step of about 1ps rise time to
approximate the ideal step
response.
• A non zero rise time input could
give some inaccuracy when using
these responses to get a BTM
model [11].

• In the following slides this error
25
will be estimated.
Comments on simulations
•
•
•
•
•
•

MC10 & DWS by using RL-TL model compute the same waveforms
and are used as reference being validated experimentally [1,2,3].
MWS & CS provide similar waveforms with less losses respect to
RL-TL model, as verified in [1,2].
MWS waveforms evolves more rapidly than CS towards dc values
for high values of time.
S11 of DWS shows a small ringing due to finite number of cell
segmentation.
This effect can be eliminated by using more unit cells (example 100
as done with MC10).
DWS simulations are very fast (50+ times faster than MC 10) at
equal cell number.

26
S11&S21 computed by analytic
approach (Theory)
Analytic method
•

•
•
•
•
•

The method used for computing S11 & S21 in time domain is outlined in
[4] and with more details in chapter 7, subparagraph 7.1.5.2 of [6].
A linear ramp of tr=25ps for a cable length of 18.3cm and tr=100ps for
1.83m are used as input .
Tangent delta (θo) is set to 0.8m, see Appendix.
Skin effect is computed by Eq.7.57 of [6] by using a factor ½ for
comparison with CS and without the factor ½ for comparison with RL-TL
model.
MathCad code professional 2001i is used for analytic computations.
The comparisons are performed among: RL-TL model (RL-TL), Cable
Studio ohmic losses (cs), Cable Studio ohmic+dielectric losses (cs_d),
analytic results with all losses (Theory).
Line structure & input signal
Source signal: tr=25ps

Zocoax

Vsin (1+S11)

Len
Vl (S21)

Vs=2V
Zocoax
tr (10%-90%)
Coaxial cable
rw: wire radius
rsh : internal shield radius
dcoax: shield thickness
Skin effect (compact expressions)

½ factor

• In [5], Ziwcoaxb and Zishcoaxb expressions for a coaxial cable, are reported without the
factor ½, while for a round wire the factor ½ should be used.
•It will be shown that cs waveforms are in agreement with theory using factor ½
(round wire) while RL-TL waveforms are in agreement with theory without factor ½
because vector fitting technique (VFT) was applied starting from these expressions.
Skin effect impedances (Ohm/m)
•ZiSkinw Internal wire
impedance computed as round
wire, see chapter 7 of [6] for
the expressions.
•Ziwcoaxb Internal wire
impedance computed by
compact expression with ½
factor.
•Zishcoaxb Shield impedance
computed by compact
expression with ½ factor.
• ZiSkin= Ziwcoaxb+ Zishcoaxb Total
impedance of the cable

ZiSkinw and Ziwcoaxb provide the same values
See also the results reported in [3] for the 18.3cm RG58 cable
Dielectric losses and line parameters

Dielectric losses

Line parametrs

For more details, see chapter 7 of [6]
Output rise time comparison (Len=18.3cm)

MC, CS, CS_d

ps

Theory

ns

• Good agreement
nevertheless a
ramp and not a
gaussian shape has
been used
• A delay of 22ps
has been introduced
into theorical result
for comparison
reasons
S11&S21 computed with factor ½
(Len=18.3cm)

cs_d

cs_d

Theory

• Good agreement
between cs_d and
theory
• S11 of theory is
slightly lower
S11&S21 computed without factor ½
(Len=18.3cm)

•Very good agreement
between RL-TL model
and theory

RL-TL

RL-TL

ps

Theory
ns

•The reason is that the
RL-TL model was
obtained by VFT using
compact skin effect
expressions for coaxial
cable without factor ½.
S11 computed with factor ½ (Len=1.83m)

Theory
Cable studio
(Bandwith=10GHz)

CST provides slightly lower values
S21 computed with factor ½ (Len=1.83m)

Theory
Both methods provide the same values
Cable studio
(Bandwith=10GHz)
1+S11 computed without factor ½
(Len=1.83m)

Theory
Cable studio
(Bandwith=10GHz)

Theory provides more than doubled values for S11
S21 computed without factor ½ (Len=1.83m)

Theory
Theory computes slight lower rising edge values
Cable studio
after the 80% of its DC level
(Bandwith=10GHz)
Comments on analytic approach
•
•
•

•

Good agreement between CS and theory waveforms considering all
losses.
RL-TL model overestimates the losses due to the lack of .5 factor in
skin effect compact expressions used to get the equivalent RL circuit
by Vector Fitting Technique.
This difference compensates the lack of dielectric losses in the model
RL-TL and justifies the good agreement with the measured waveform
tails as shown in [2,3].
The S21 rising edge coming from the RL-TL model is too fast due to
lack of dielectric losses and can be compensated using a DWS
RL_LTL hybrid model as shown in [8]
Cable Studio results as source of a
BTM of a 1.83-m RG58 coaxial cable
used in DWS

41
Used BTM procedure
•

•
•
•

The S11 and S21 computed by cable studio (CS) 2013 for a 18.3cm of RG58 (0-40GHz) have been used as sources to get the
Behavioral Transmission Model (BTM) in DWS.
The waveforms obtained from a 1ps ramp input are used in the
BTM model as PWL approximations and not directly as ASCII file
(both ways provided by DWS) to speed up the simulations .
For comparisons, a ramp of 25ps is also considered.
DWS has been used to compute VS&VL voltages obtained from a
cascade of 10 BTM with a ramp input. The waveforms are compared
with those computed by CS 2013 using a model valid in the range 010GHz.
CS VS&VL (cable length=18.3cm, model:040GHz,tandelta=0.0)
tr=25ps
1+S11
A fixed time step of
0.1ps has been used
for CS simulation tasks

tr=1ps
1+S11

S21

S-parameter
waveforms do not
seem influenced
by the tr, apart the
oscillations in S11
43
CS VS&VL (cable length=18.3cm, model:040GHz,tandelta=0.8m)
tr=25ps
1+S11
A fixed time step of
0.1ps has been used

S21

tr=1ps
1+S11

S21

S11 waveform
does not seem
influenced by the
tr, apart the
oscillations in S11
44
VS&VL (cable length=18.3cm, model:040GHz,tandelta=0.8m): extended time scale
1+S11

tr=25ps

S21

Time step=1ps
Samples=4001

Zoom

45
VL edge detail (cable length=18.3cm, model:040GHz,tandelta=0.8m)
tr=25ps

S21

Time step=0.1ps
Samples= 4001

tr=1ps

S21

Time step=0.02ps
Samples= 8001

•S21 rising edge is
strongly influenced
by input tr
• Waveform from
1ps stimulus can
be used to extract
BTM models using
46
the PWL technique
PWL generation

PWL generation: The CS output waveform is digitized by extracting the time and
amplitude values at user chosen points (see small circles along the waveform).
The manual choice is performed with the aim of minimizing the number of points
but still achieving a good accuracy .This can been accomplished by a graphic
digitizer program due to the availability of the image files. In case of ASCII files
compatible with the .g format of DWS, a DWV viewer feature is provided to
quickly accomplish this task in a semi-automatic way.
VS&VL (cable length=1.83m, model:0-10GHz,
tandelta=0.8m, tr=25ps)
V

1+S11

CS 2013

Cascade of
10 BTM cells
with DWS

S21

ns

V

1+S11
S11 & S21
waveforms are in
good agreement
ns

48
VL (S21) edge detail (cable length=1.83m, model:010GHz, tandelta=0.8m, tr=25ps)
V
CS 2013

S21
Cascade of
10 BTM cells
with DWS

ns

• S21 waveforms are in good agreement
• S21 rising edge computed by 10 BTM seems to be a little lower
49
Comments on BTM results
•

The S11 waveform obtained by DWS from a chain of 10 BTM
cells derived from CS is in good agreement with the one obtained
by CS for the total length of the cable
The S21 edge obtained by a cascade of 10 BTM cells seems to
be slightly faster than the one obtained by a CS for the total length
of cable
There are some key points to be taken into account in using the
cascade of BTM cells :

•
•

1.
2.

3
4

A fast (1ps) edge has to be used as input stimulus to extract the BTM
model of the unit cell. A slower rise time stimulus as 25ps would
introduce a significant error in computing the S21 edge [11].
A suitable bandwidth (e.g. 40Ghz) has to be set in CS to get an
accurate response to the 1ps input required for the BTM model.
This bandwidth determines the number of cascaded RLCTL cells of
the CS circuital model (100-cell for a 183mm long cable) and the
simulation time of CS.
BTM model accuracy depends on the number and placement of the
breakpoints chosen for the pwl behavior. Normally 20-30 breakpoints
are enough to get a good speed/accuracy trade off.
An impressive DWS vs speedup factor (3 to 4 orders of magnitude) is
obtained for “long” cables using chain of BTM cells
Analytical methods used to extract
a 1-m unit cell BTM to simulate a
10-m RG58 coaxial cable with
DWS
Procedure adopted for BTM cell extraction

•

•
•

The theoretical expressions previously shown in this report are used
to get approximated S11 and S21 step responses for a 1-m RG58
cable. Two different ramps of tr=5ps and tr=25ps respectively are
used as input stimuli.
The computed waveforms are digitized to get the breakpoints for
build up the pwl BTM cell model
A chain of 10 equal cells is simulated by DWS to get the response of
a 10-meter cable.
Signals & line voltages for 1-m of RG58
Tr=25p
s

S21
Data used as input for BTM

S11
Tp
Data used as input for BTM

Time period Tp should be large enough to reach with approximation the dc values of S11
Signals & line voltages for 10-m of RG58
Source signal: tr=100ps

Line voltages: input (vsin) & output (vl)

Tp

Time period Tp should be large enough to reach
with approximation the dc values of S11
S21 (vl) rising edge (10-m cable)

Edge computed by Theory

Edge computed by DWS using 10 BTM cells with tr=5ps
Edge computed by DWS using 10 BTM cells with tr=25ps
S21 (vl) rising edge of a 10-m cable: detailed view
with equalized delays for edge comparison

Edge computed by Theory

Edge computed by DWS using 10 BTM cells with tr=5ps
Edge computed by DWS using 10 BTM cells with tr=25ps

As expected [11], better agreement is obtained
by using tr=5ps as input for the 1m basic cell
S11

reflections computed by Theory
reflections computed by DWS by using 10 BTM with tr=5ps

The difference after t=40ns is due to S11 behavior truncation after the first
40ns window. Beyond 40ns the analytical S11 response was not available
due to FFT issues. At least a 400ns window should be required.
BTM model from theoretical responses: key points

1.

2.

3.

As for the BTM model extracted from Cable Studio simulations,
some key points have to be pointed out:
The S21 rising edge should be computed by IFFT using an
enough short rise-time ramp as input (e.g. 5ps for 1-m cable) to
limit the rise time error of the BTM cells cascade [11].
The reflection coefficient (S11) should be computed using an
input stimulus period enough large to allow a good
approximation of steady state (dc ) values. A tradeoff between
this period and IFFT computation time is required. Therefore, a
global tradeoff is needed to take into account accuracy
requirement for simulations, fast tr, and large period Tp for IFFT
computation.
The BTM model extracted taking into account previous points is
very fast and achieves a good accuracy level.
Using Cable Studio: user considerations
•
•
•
•
•

•

•
•
•

•

The results of CS are strongly influenced by several options set by the user.
The effect of options on final results is not always clear to the user.
TLM (modal) option is required to get accurate results.
TLM produces circuital models including thousands of RLC and TL elements.
The unit cell TL delay can be a number like TD=9.54361271247e-012 sec. This kind of
values requires to set short fixed time step (e.g. 100fs) to get reliable results from
CS simulations . Otherwise overall delay and behavior of a 100-cell cascade can be
strongly affected.
The Bandwidth to be set to get the modal TLM directly affects the number of
cascaded cells in the cable model . For example a 40Ghz BW generates a 100-cell
model for a 18.3 cm cable.
CS 2013/14 simulations at fixed step can require several minute on a multicore CPU.
DWS can achieve a 10-50X speed up over CS to simulate complex TLM models
generated by CS [13 ].
To extract accurate BTM models for DWS, a rise time of about 1ps for a 20-cm unit cell
and 5ps for a 1-m unit cell is suggested as stimulus signal of the cable.
The same rule of thumb should be utilized to extract BTM models from analytical
methods.
59
Conclusions
•

•
•

•
•

•

•
•

Cable Studio computes the step responses of the cable in good agreement
with MWS and the analytic approach based on theory.
RL-TL circuital model provides overestimation of losses because the VFT used
for getting the equivalent RL circuit was applied by using compact analytic
expression for coaxial cable without the factor ½ [6].
This factor compensates the lack of dielectric losses in the RL-TL model with
the exception of S21 rising edge. A closer result with the measurement is
shown in [2] and [3]. An improved RL-TL hybrid circuital-BTM model is shown
in [8].
A BTM cell model cannot be practically obtained by a 3D model (MWS)
because the number of mesh cells required by a source with rise time in the
order of 1 ps is too large for the computation.
A BTM cell can be obtained by a 2D model (CS) feasible with a good tradeoff
between the CS input bandwidth and the stimulus rise time.
The analytical approach is feasible to get the BTM model. A tradeoff is
needed between the required fast input rise time and large period value used
for the IFFT computation. A two-step modeling using two different theoretical
responses (fast edge & short period, slower edge & larger period) should give
the best results
DWS can be used with major speed benefits both for TLM (10 to 50X) and
BTM (up to 10000X) cable models
DWS can also utilize both hybrid ( BTM and TLM) and full BTM models
directly extracted or optimized to actual TDR measures [8].
60
Appendix:
Dielectric losses (Tanδ)
Typical Tanδ values
• The following tables are extracted from the
literature.
• They should be compared with the value
of Tanδ=0.8m used in this report.
Tandδ
http://cp.literature.agilent.com/litweb/pdf/genesys200801/elements/substrate_tables/t
ablelosstan.htm
The dielectric loss tangents for some materials commonly used in coaxial cables are:
tanD at 100 MHz

tanD at 3 GHz

Air

0.0

0.0

PTFE

2E-4

15E-4

PolyEthylene, DE-3401

2E-4

3.1E-4

Polyolefin, irradiated

3E-4

3E-4

Polystyrene

1E-4

3.3E-4

Polyvinal formal (Formvar)

1.3E-2

1.1E-2

Nylon

2E-2

1.2E-2

Quartz, fused

2E-4

6E-5

Pyrex Glass

3E-3

5.4E-3

Water, distilled

5E-3

1.6E-1

Material

For simulation we have used Tanδ=8e-4 (used in CST as default value)

63
Tandδ (coax Belden)

For RG58, a tanδ between
1.12e-3 and 2.12e-3 are given
(values higher than the previous
table for polyethylene)
Tandelta
From: H. Johnson, M. Graham, “High-Speed Signal Propagation”, Prentice Hall, 2003
64
References
[1] Piero Belforte, Spartaco Caniggia, “CST coaxial cable models for
SI simulations: a comparative study”, March 24th 2013CST
models for theRG58 coax cable
[2] Piero Belforte, Spartaco Caniggia,, “Measurements and
Simulations with1.83-m RG58 cable”, April 5th 2013
[3] Piero Belforte, Spartaco Caniggia, “TDR measurements and
simulations of RGU 58 coaxial cable S-parameters”, June 04,
2013 TDR measures and simulations of RG58 cable
[4] Spartaco Caniggia, “Modeling interconnects and power
distribution network in PCBs, CST workshops, Milano, 26-11-2013
[5] Ramo, Whinnery, Van Duzer, “Fields and wave in communication
electronics”, John Wiley, 3rd Edition
[6] S. Caniggia, F. Maradei, “Signal Integrity and Radiated Emission
of High-Speed Digital Systems”, John Wiley & Sons, 2008

65
References (2)
[7] Piero Belforte “ TDR mesurements of RG58 coaxial cable Sparameters”, April11th 2013 TDR measurements of RG58 coax cable
[8] Piero Belforte “ RG58 coaxial cable: A comparison among Analytical
models, DWS BTM models, TDR measures and CST 2013 Cable
Studio simulations”, Dec. 24th 2013 Models and measurements for a
RG58 coax
[9] Piero Belforte “A new modeling and simulation environment for highperformance digital systems” HP Digital Symposium (1993)
[10] Piero Belforte “DWS vs MC10: a comparative benchmark” April 15th
2013 DWS vs MC10
[11] Piero Belforte “ Prediction of rise time errors of a cascade of equal
behavioral cells” May 2nd 2013 Rise time error prediction
[12] http://ischematics.com/
[13] SWAN sim of a CST2014 TLM cable model

66

Weitere ähnliche Inhalte

Was ist angesagt?

Chapter 14
Chapter 14Chapter 14
Chapter 14Tha Mike
 
Chapter 03
Chapter 03Chapter 03
Chapter 03Tha Mike
 
Chapter 05
Chapter 05Chapter 05
Chapter 05Tha Mike
 
Lect2 up330 (100328)
Lect2 up330 (100328)Lect2 up330 (100328)
Lect2 up330 (100328)aicdesign
 
Chapter 04a
Chapter 04aChapter 04a
Chapter 04aTha Mike
 
Chapter 02
Chapter 02Chapter 02
Chapter 02Tha Mike
 
Chapter 17
Chapter 17Chapter 17
Chapter 17Tha Mike
 
IC Design of Power Management Circuits (II)
IC Design of Power Management Circuits (II)IC Design of Power Management Circuits (II)
IC Design of Power Management Circuits (II)Claudia Sin
 
Chapter 18
Chapter 18Chapter 18
Chapter 18Tha Mike
 
Ee6378 bandgap reference
Ee6378 bandgap referenceEe6378 bandgap reference
Ee6378 bandgap referencessuser2038c9
 
Journal On LDO From IJEETC
Journal On LDO From IJEETCJournal On LDO From IJEETC
Journal On LDO From IJEETCSadanand Patil
 
minimisation of crosstalk in VLSI routing
minimisation of crosstalk in VLSI routingminimisation of crosstalk in VLSI routing
minimisation of crosstalk in VLSI routingChandrajit Pal
 
crosstalk minimisation using vlsi
crosstalk minimisation using vlsicrosstalk minimisation using vlsi
crosstalk minimisation using vlsisubhradeep mitra
 
Chapter 08
Chapter 08Chapter 08
Chapter 08Tha Mike
 
Lect2 up290 (100328)
Lect2 up290 (100328)Lect2 up290 (100328)
Lect2 up290 (100328)aicdesign
 
Optimization of Packet Length for Two Way Relaying with Energy Harvesting
Optimization of Packet Length for Two Way Relaying with Energy HarvestingOptimization of Packet Length for Two Way Relaying with Energy Harvesting
Optimization of Packet Length for Two Way Relaying with Energy HarvestingIJCNCJournal
 

Was ist angesagt? (20)

Chapter 14
Chapter 14Chapter 14
Chapter 14
 
Chapter 03
Chapter 03Chapter 03
Chapter 03
 
Chapter 05
Chapter 05Chapter 05
Chapter 05
 
ECNG 3013 E
ECNG 3013 EECNG 3013 E
ECNG 3013 E
 
Lect2 up330 (100328)
Lect2 up330 (100328)Lect2 up330 (100328)
Lect2 up330 (100328)
 
Chapter 04a
Chapter 04aChapter 04a
Chapter 04a
 
Chapter 02
Chapter 02Chapter 02
Chapter 02
 
Lecture 5
Lecture 5Lecture 5
Lecture 5
 
Chapter 17
Chapter 17Chapter 17
Chapter 17
 
IC Design of Power Management Circuits (II)
IC Design of Power Management Circuits (II)IC Design of Power Management Circuits (II)
IC Design of Power Management Circuits (II)
 
Chapter 18
Chapter 18Chapter 18
Chapter 18
 
Ee6378 bandgap reference
Ee6378 bandgap referenceEe6378 bandgap reference
Ee6378 bandgap reference
 
Journal On LDO From IJEETC
Journal On LDO From IJEETCJournal On LDO From IJEETC
Journal On LDO From IJEETC
 
minimisation of crosstalk in VLSI routing
minimisation of crosstalk in VLSI routingminimisation of crosstalk in VLSI routing
minimisation of crosstalk in VLSI routing
 
ECNG 3013 D
ECNG 3013 DECNG 3013 D
ECNG 3013 D
 
crosstalk minimisation using vlsi
crosstalk minimisation using vlsicrosstalk minimisation using vlsi
crosstalk minimisation using vlsi
 
ECNG 3013 B
ECNG 3013 BECNG 3013 B
ECNG 3013 B
 
Chapter 08
Chapter 08Chapter 08
Chapter 08
 
Lect2 up290 (100328)
Lect2 up290 (100328)Lect2 up290 (100328)
Lect2 up290 (100328)
 
Optimization of Packet Length for Two Way Relaying with Energy Harvesting
Optimization of Packet Length for Two Way Relaying with Energy HarvestingOptimization of Packet Length for Two Way Relaying with Energy Harvesting
Optimization of Packet Length for Two Way Relaying with Energy Harvesting
 

Ähnlich wie Rg58 s par theory cst_spice_dws_final

2013 06 tdr measurement and simulation of rg58 coaxial cable s-parameters_final
2013 06 tdr measurement and simulation  of rg58 coaxial cable s-parameters_final2013 06 tdr measurement and simulation  of rg58 coaxial cable s-parameters_final
2013 06 tdr measurement and simulation of rg58 coaxial cable s-parameters_finalPiero Belforte
 
Introduction to microwaves
Introduction to microwavesIntroduction to microwaves
Introduction to microwavesTapas Mondal
 
Lect2 up380 (100329)
Lect2 up380 (100329)Lect2 up380 (100329)
Lect2 up380 (100329)aicdesign
 
A new precision peak detector full wave rectifier
A new precision peak detector full wave rectifierA new precision peak detector full wave rectifier
A new precision peak detector full wave rectifierVishal kakade
 
DESIGN OF V-BAND SUBSTRATE INTEGRATED WAVEGUIDE POWER DIVIDER, CIRCULATOR AND...
DESIGN OF V-BAND SUBSTRATE INTEGRATED WAVEGUIDE POWER DIVIDER, CIRCULATOR AND...DESIGN OF V-BAND SUBSTRATE INTEGRATED WAVEGUIDE POWER DIVIDER, CIRCULATOR AND...
DESIGN OF V-BAND SUBSTRATE INTEGRATED WAVEGUIDE POWER DIVIDER, CIRCULATOR AND...cscpconf
 
DESIGN OF V-BAND SUBSTRATE INTEGRATED WAVEGUIDE POWER DIVIDER, CIRCULATOR AND...
DESIGN OF V-BAND SUBSTRATE INTEGRATED WAVEGUIDE POWER DIVIDER, CIRCULATOR AND...DESIGN OF V-BAND SUBSTRATE INTEGRATED WAVEGUIDE POWER DIVIDER, CIRCULATOR AND...
DESIGN OF V-BAND SUBSTRATE INTEGRATED WAVEGUIDE POWER DIVIDER, CIRCULATOR AND...csandit
 
Design of v band substrate
Design of v band substrateDesign of v band substrate
Design of v band substratecsandit
 
Design of v band substrate
Design of v band substrateDesign of v band substrate
Design of v band substratecsandit
 
Project_Kaveh & Mohammad
Project_Kaveh & MohammadProject_Kaveh & Mohammad
Project_Kaveh & MohammadKaveh Dehno
 
Design of Continuous Time Multibit Sigma Delta ADC for Next Generation Wirele...
Design of Continuous Time Multibit Sigma Delta ADC for Next Generation Wirele...Design of Continuous Time Multibit Sigma Delta ADC for Next Generation Wirele...
Design of Continuous Time Multibit Sigma Delta ADC for Next Generation Wirele...IJERA Editor
 
A Low Power Low Voltage High Performance CMOS Current Mirror
A Low Power Low Voltage High Performance CMOS Current MirrorA Low Power Low Voltage High Performance CMOS Current Mirror
A Low Power Low Voltage High Performance CMOS Current MirrorIJERA Editor
 
Analytical Delay Model for Distributed On-Chip RLCG Global Interconnects for ...
Analytical Delay Model for Distributed On-Chip RLCG Global Interconnects for ...Analytical Delay Model for Distributed On-Chip RLCG Global Interconnects for ...
Analytical Delay Model for Distributed On-Chip RLCG Global Interconnects for ...IDES Editor
 
Design of a novel current balanced voltage controlled delay element
Design of a novel current balanced voltage controlled delay elementDesign of a novel current balanced voltage controlled delay element
Design of a novel current balanced voltage controlled delay elementVLSICS Design
 
Lect2 up120 (100325)
Lect2 up120 (100325)Lect2 up120 (100325)
Lect2 up120 (100325)aicdesign
 
A transmission line based technique for de-embedding noise parameters
A transmission line based technique for de-embedding noise parametersA transmission line based technique for de-embedding noise parameters
A transmission line based technique for de-embedding noise parametersvilla1451
 
Comparative Evaluation of Three Phase Three Level Neutral Point Clamped Z-So...
Comparative Evaluation of Three Phase Three Level  Neutral Point Clamped Z-So...Comparative Evaluation of Three Phase Three Level  Neutral Point Clamped Z-So...
Comparative Evaluation of Three Phase Three Level Neutral Point Clamped Z-So...NAGARAJARAOS
 
Lect2 up110 (100324)
Lect2 up110 (100324)Lect2 up110 (100324)
Lect2 up110 (100324)aicdesign
 
High Speed, Low Offset, Low Power, Fully Dynamic Cmos Latched Comparator
High Speed, Low Offset, Low Power, Fully Dynamic Cmos Latched ComparatorHigh Speed, Low Offset, Low Power, Fully Dynamic Cmos Latched Comparator
High Speed, Low Offset, Low Power, Fully Dynamic Cmos Latched Comparatoriosrjce
 
ANALYSIS AND DESIGN OF DOUBLE TAIL COMPARATOR USING A LOW POWER GATING TECHNI...
ANALYSIS AND DESIGN OF DOUBLE TAIL COMPARATOR USING A LOW POWER GATING TECHNI...ANALYSIS AND DESIGN OF DOUBLE TAIL COMPARATOR USING A LOW POWER GATING TECHNI...
ANALYSIS AND DESIGN OF DOUBLE TAIL COMPARATOR USING A LOW POWER GATING TECHNI...RK CONSULTANCY SERVICES
 

Ähnlich wie Rg58 s par theory cst_spice_dws_final (20)

2013 06 tdr measurement and simulation of rg58 coaxial cable s-parameters_final
2013 06 tdr measurement and simulation  of rg58 coaxial cable s-parameters_final2013 06 tdr measurement and simulation  of rg58 coaxial cable s-parameters_final
2013 06 tdr measurement and simulation of rg58 coaxial cable s-parameters_final
 
Thesis presentation
Thesis presentationThesis presentation
Thesis presentation
 
Introduction to microwaves
Introduction to microwavesIntroduction to microwaves
Introduction to microwaves
 
Lect2 up380 (100329)
Lect2 up380 (100329)Lect2 up380 (100329)
Lect2 up380 (100329)
 
A new precision peak detector full wave rectifier
A new precision peak detector full wave rectifierA new precision peak detector full wave rectifier
A new precision peak detector full wave rectifier
 
DESIGN OF V-BAND SUBSTRATE INTEGRATED WAVEGUIDE POWER DIVIDER, CIRCULATOR AND...
DESIGN OF V-BAND SUBSTRATE INTEGRATED WAVEGUIDE POWER DIVIDER, CIRCULATOR AND...DESIGN OF V-BAND SUBSTRATE INTEGRATED WAVEGUIDE POWER DIVIDER, CIRCULATOR AND...
DESIGN OF V-BAND SUBSTRATE INTEGRATED WAVEGUIDE POWER DIVIDER, CIRCULATOR AND...
 
DESIGN OF V-BAND SUBSTRATE INTEGRATED WAVEGUIDE POWER DIVIDER, CIRCULATOR AND...
DESIGN OF V-BAND SUBSTRATE INTEGRATED WAVEGUIDE POWER DIVIDER, CIRCULATOR AND...DESIGN OF V-BAND SUBSTRATE INTEGRATED WAVEGUIDE POWER DIVIDER, CIRCULATOR AND...
DESIGN OF V-BAND SUBSTRATE INTEGRATED WAVEGUIDE POWER DIVIDER, CIRCULATOR AND...
 
Design of v band substrate
Design of v band substrateDesign of v band substrate
Design of v band substrate
 
Design of v band substrate
Design of v band substrateDesign of v band substrate
Design of v band substrate
 
Project_Kaveh & Mohammad
Project_Kaveh & MohammadProject_Kaveh & Mohammad
Project_Kaveh & Mohammad
 
Design of Continuous Time Multibit Sigma Delta ADC for Next Generation Wirele...
Design of Continuous Time Multibit Sigma Delta ADC for Next Generation Wirele...Design of Continuous Time Multibit Sigma Delta ADC for Next Generation Wirele...
Design of Continuous Time Multibit Sigma Delta ADC for Next Generation Wirele...
 
A Low Power Low Voltage High Performance CMOS Current Mirror
A Low Power Low Voltage High Performance CMOS Current MirrorA Low Power Low Voltage High Performance CMOS Current Mirror
A Low Power Low Voltage High Performance CMOS Current Mirror
 
Analytical Delay Model for Distributed On-Chip RLCG Global Interconnects for ...
Analytical Delay Model for Distributed On-Chip RLCG Global Interconnects for ...Analytical Delay Model for Distributed On-Chip RLCG Global Interconnects for ...
Analytical Delay Model for Distributed On-Chip RLCG Global Interconnects for ...
 
Design of a novel current balanced voltage controlled delay element
Design of a novel current balanced voltage controlled delay elementDesign of a novel current balanced voltage controlled delay element
Design of a novel current balanced voltage controlled delay element
 
Lect2 up120 (100325)
Lect2 up120 (100325)Lect2 up120 (100325)
Lect2 up120 (100325)
 
A transmission line based technique for de-embedding noise parameters
A transmission line based technique for de-embedding noise parametersA transmission line based technique for de-embedding noise parameters
A transmission line based technique for de-embedding noise parameters
 
Comparative Evaluation of Three Phase Three Level Neutral Point Clamped Z-So...
Comparative Evaluation of Three Phase Three Level  Neutral Point Clamped Z-So...Comparative Evaluation of Three Phase Three Level  Neutral Point Clamped Z-So...
Comparative Evaluation of Three Phase Three Level Neutral Point Clamped Z-So...
 
Lect2 up110 (100324)
Lect2 up110 (100324)Lect2 up110 (100324)
Lect2 up110 (100324)
 
High Speed, Low Offset, Low Power, Fully Dynamic Cmos Latched Comparator
High Speed, Low Offset, Low Power, Fully Dynamic Cmos Latched ComparatorHigh Speed, Low Offset, Low Power, Fully Dynamic Cmos Latched Comparator
High Speed, Low Offset, Low Power, Fully Dynamic Cmos Latched Comparator
 
ANALYSIS AND DESIGN OF DOUBLE TAIL COMPARATOR USING A LOW POWER GATING TECHNI...
ANALYSIS AND DESIGN OF DOUBLE TAIL COMPARATOR USING A LOW POWER GATING TECHNI...ANALYSIS AND DESIGN OF DOUBLE TAIL COMPARATOR USING A LOW POWER GATING TECHNI...
ANALYSIS AND DESIGN OF DOUBLE TAIL COMPARATOR USING A LOW POWER GATING TECHNI...
 

Mehr von Piero Belforte

Simulation-modeling matrix
Simulation-modeling matrixSimulation-modeling matrix
Simulation-modeling matrixPiero Belforte
 
Frequency domain behavior of S-parameters piecewise-linear fitting in a digit...
Frequency domain behavior of S-parameters piecewise-linear fitting in a digit...Frequency domain behavior of S-parameters piecewise-linear fitting in a digit...
Frequency domain behavior of S-parameters piecewise-linear fitting in a digit...Piero Belforte
 
3 experimental wideband_characterization_of_a parallel-plate_capacitor
3 experimental wideband_characterization_of_a parallel-plate_capacitor3 experimental wideband_characterization_of_a parallel-plate_capacitor
3 experimental wideband_characterization_of_a parallel-plate_capacitorPiero Belforte
 
Automated Piecewise-Linear Fitting of S-Parameters step-response (PWLFIT) for...
Automated Piecewise-Linear Fitting of S-Parameters step-response (PWLFIT) for...Automated Piecewise-Linear Fitting of S-Parameters step-response (PWLFIT) for...
Automated Piecewise-Linear Fitting of S-Parameters step-response (PWLFIT) for...Piero Belforte
 
Cseltmuseum post records from September 2018 to January2019
Cseltmuseum post records from September 2018 to January2019Cseltmuseum post records from September 2018 to January2019
Cseltmuseum post records from September 2018 to January2019Piero Belforte
 
Cseltmuseum post records August2018
Cseltmuseum post records August2018Cseltmuseum post records August2018
Cseltmuseum post records August2018Piero Belforte
 
Cseltmuseum post records July 2018
Cseltmuseum post records July 2018Cseltmuseum post records July 2018
Cseltmuseum post records July 2018Piero Belforte
 
Multigigabit modeling of hi safe+ flying probe fp011
Multigigabit modeling of hi safe+ flying probe fp011Multigigabit modeling of hi safe+ flying probe fp011
Multigigabit modeling of hi safe+ flying probe fp011Piero Belforte
 
Cseltmuseum post records June 2018
Cseltmuseum post records June 2018Cseltmuseum post records June 2018
Cseltmuseum post records June 2018Piero Belforte
 
CSELTMUSEUM POST RECORDS MAY 2018
CSELTMUSEUM POST RECORDS MAY 2018CSELTMUSEUM POST RECORDS MAY 2018
CSELTMUSEUM POST RECORDS MAY 2018Piero Belforte
 
CSELTMUSEUM POST RECORDS APRIL 2018
CSELTMUSEUM POST RECORDS APRIL 2018CSELTMUSEUM POST RECORDS APRIL 2018
CSELTMUSEUM POST RECORDS APRIL 2018Piero Belforte
 
CSELTMUSEUM post records March_2018
CSELTMUSEUM  post records March_2018CSELTMUSEUM  post records March_2018
CSELTMUSEUM post records March_2018Piero Belforte
 
CSELTMUSEUM POST RECORDS FEBRUARY 2018
CSELTMUSEUM POST RECORDS FEBRUARY  2018CSELTMUSEUM POST RECORDS FEBRUARY  2018
CSELTMUSEUM POST RECORDS FEBRUARY 2018Piero Belforte
 
CSELTMUSEUM POST RECORDS JANUARY 2018
CSELTMUSEUM POST RECORDS JANUARY 2018CSELTMUSEUM POST RECORDS JANUARY 2018
CSELTMUSEUM POST RECORDS JANUARY 2018Piero Belforte
 
CSELTMUSEUM expanded post records, December 2017
CSELTMUSEUM expanded post records, December 2017CSELTMUSEUM expanded post records, December 2017
CSELTMUSEUM expanded post records, December 2017Piero Belforte
 
HDT (High Design Technology) related content on Cseltmuseum Dec. 13 2017
HDT (High Design Technology) related content on Cseltmuseum  Dec. 13 2017HDT (High Design Technology) related content on Cseltmuseum  Dec. 13 2017
HDT (High Design Technology) related content on Cseltmuseum Dec. 13 2017Piero Belforte
 
HiSAFE related content on Cseltmuseum Dec. 13 2017
HiSAFE related content on Cseltmuseum Dec. 13 2017 HiSAFE related content on Cseltmuseum Dec. 13 2017
HiSAFE related content on Cseltmuseum Dec. 13 2017 Piero Belforte
 
CSELTMUSEUM post record August to December 2017
 CSELTMUSEUM post record August to December 2017 CSELTMUSEUM post record August to December 2017
CSELTMUSEUM post record August to December 2017Piero Belforte
 
Piero Belforte related presentations on slideplayer.com july 12 2017
Piero Belforte related presentations on slideplayer.com july 12 2017Piero Belforte related presentations on slideplayer.com july 12 2017
Piero Belforte related presentations on slideplayer.com july 12 2017Piero Belforte
 
Collection of Cselt related presentations on slideplayer.com by_Piero_Belfort...
Collection of Cselt related presentations on slideplayer.com by_Piero_Belfort...Collection of Cselt related presentations on slideplayer.com by_Piero_Belfort...
Collection of Cselt related presentations on slideplayer.com by_Piero_Belfort...Piero Belforte
 

Mehr von Piero Belforte (20)

Simulation-modeling matrix
Simulation-modeling matrixSimulation-modeling matrix
Simulation-modeling matrix
 
Frequency domain behavior of S-parameters piecewise-linear fitting in a digit...
Frequency domain behavior of S-parameters piecewise-linear fitting in a digit...Frequency domain behavior of S-parameters piecewise-linear fitting in a digit...
Frequency domain behavior of S-parameters piecewise-linear fitting in a digit...
 
3 experimental wideband_characterization_of_a parallel-plate_capacitor
3 experimental wideband_characterization_of_a parallel-plate_capacitor3 experimental wideband_characterization_of_a parallel-plate_capacitor
3 experimental wideband_characterization_of_a parallel-plate_capacitor
 
Automated Piecewise-Linear Fitting of S-Parameters step-response (PWLFIT) for...
Automated Piecewise-Linear Fitting of S-Parameters step-response (PWLFIT) for...Automated Piecewise-Linear Fitting of S-Parameters step-response (PWLFIT) for...
Automated Piecewise-Linear Fitting of S-Parameters step-response (PWLFIT) for...
 
Cseltmuseum post records from September 2018 to January2019
Cseltmuseum post records from September 2018 to January2019Cseltmuseum post records from September 2018 to January2019
Cseltmuseum post records from September 2018 to January2019
 
Cseltmuseum post records August2018
Cseltmuseum post records August2018Cseltmuseum post records August2018
Cseltmuseum post records August2018
 
Cseltmuseum post records July 2018
Cseltmuseum post records July 2018Cseltmuseum post records July 2018
Cseltmuseum post records July 2018
 
Multigigabit modeling of hi safe+ flying probe fp011
Multigigabit modeling of hi safe+ flying probe fp011Multigigabit modeling of hi safe+ flying probe fp011
Multigigabit modeling of hi safe+ flying probe fp011
 
Cseltmuseum post records June 2018
Cseltmuseum post records June 2018Cseltmuseum post records June 2018
Cseltmuseum post records June 2018
 
CSELTMUSEUM POST RECORDS MAY 2018
CSELTMUSEUM POST RECORDS MAY 2018CSELTMUSEUM POST RECORDS MAY 2018
CSELTMUSEUM POST RECORDS MAY 2018
 
CSELTMUSEUM POST RECORDS APRIL 2018
CSELTMUSEUM POST RECORDS APRIL 2018CSELTMUSEUM POST RECORDS APRIL 2018
CSELTMUSEUM POST RECORDS APRIL 2018
 
CSELTMUSEUM post records March_2018
CSELTMUSEUM  post records March_2018CSELTMUSEUM  post records March_2018
CSELTMUSEUM post records March_2018
 
CSELTMUSEUM POST RECORDS FEBRUARY 2018
CSELTMUSEUM POST RECORDS FEBRUARY  2018CSELTMUSEUM POST RECORDS FEBRUARY  2018
CSELTMUSEUM POST RECORDS FEBRUARY 2018
 
CSELTMUSEUM POST RECORDS JANUARY 2018
CSELTMUSEUM POST RECORDS JANUARY 2018CSELTMUSEUM POST RECORDS JANUARY 2018
CSELTMUSEUM POST RECORDS JANUARY 2018
 
CSELTMUSEUM expanded post records, December 2017
CSELTMUSEUM expanded post records, December 2017CSELTMUSEUM expanded post records, December 2017
CSELTMUSEUM expanded post records, December 2017
 
HDT (High Design Technology) related content on Cseltmuseum Dec. 13 2017
HDT (High Design Technology) related content on Cseltmuseum  Dec. 13 2017HDT (High Design Technology) related content on Cseltmuseum  Dec. 13 2017
HDT (High Design Technology) related content on Cseltmuseum Dec. 13 2017
 
HiSAFE related content on Cseltmuseum Dec. 13 2017
HiSAFE related content on Cseltmuseum Dec. 13 2017 HiSAFE related content on Cseltmuseum Dec. 13 2017
HiSAFE related content on Cseltmuseum Dec. 13 2017
 
CSELTMUSEUM post record August to December 2017
 CSELTMUSEUM post record August to December 2017 CSELTMUSEUM post record August to December 2017
CSELTMUSEUM post record August to December 2017
 
Piero Belforte related presentations on slideplayer.com july 12 2017
Piero Belforte related presentations on slideplayer.com july 12 2017Piero Belforte related presentations on slideplayer.com july 12 2017
Piero Belforte related presentations on slideplayer.com july 12 2017
 
Collection of Cselt related presentations on slideplayer.com by_Piero_Belfort...
Collection of Cselt related presentations on slideplayer.com by_Piero_Belfort...Collection of Cselt related presentations on slideplayer.com by_Piero_Belfort...
Collection of Cselt related presentations on slideplayer.com by_Piero_Belfort...
 

Kürzlich hochgeladen

From Event to Action: Accelerate Your Decision Making with Real-Time Automation
From Event to Action: Accelerate Your Decision Making with Real-Time AutomationFrom Event to Action: Accelerate Your Decision Making with Real-Time Automation
From Event to Action: Accelerate Your Decision Making with Real-Time AutomationSafe Software
 
AI as an Interface for Commercial Buildings
AI as an Interface for Commercial BuildingsAI as an Interface for Commercial Buildings
AI as an Interface for Commercial BuildingsMemoori
 
[2024]Digital Global Overview Report 2024 Meltwater.pdf
[2024]Digital Global Overview Report 2024 Meltwater.pdf[2024]Digital Global Overview Report 2024 Meltwater.pdf
[2024]Digital Global Overview Report 2024 Meltwater.pdfhans926745
 
The 7 Things I Know About Cyber Security After 25 Years | April 2024
The 7 Things I Know About Cyber Security After 25 Years | April 2024The 7 Things I Know About Cyber Security After 25 Years | April 2024
The 7 Things I Know About Cyber Security After 25 Years | April 2024Rafal Los
 
IAC 2024 - IA Fast Track to Search Focused AI Solutions
IAC 2024 - IA Fast Track to Search Focused AI SolutionsIAC 2024 - IA Fast Track to Search Focused AI Solutions
IAC 2024 - IA Fast Track to Search Focused AI SolutionsEnterprise Knowledge
 
Kotlin Multiplatform & Compose Multiplatform - Starter kit for pragmatics
Kotlin Multiplatform & Compose Multiplatform - Starter kit for pragmaticsKotlin Multiplatform & Compose Multiplatform - Starter kit for pragmatics
Kotlin Multiplatform & Compose Multiplatform - Starter kit for pragmaticscarlostorres15106
 
Azure Monitor & Application Insight to monitor Infrastructure & Application
Azure Monitor & Application Insight to monitor Infrastructure & ApplicationAzure Monitor & Application Insight to monitor Infrastructure & Application
Azure Monitor & Application Insight to monitor Infrastructure & ApplicationAndikSusilo4
 
Tech-Forward - Achieving Business Readiness For Copilot in Microsoft 365
Tech-Forward - Achieving Business Readiness For Copilot in Microsoft 365Tech-Forward - Achieving Business Readiness For Copilot in Microsoft 365
Tech-Forward - Achieving Business Readiness For Copilot in Microsoft 3652toLead Limited
 
08448380779 Call Girls In Greater Kailash - I Women Seeking Men
08448380779 Call Girls In Greater Kailash - I Women Seeking Men08448380779 Call Girls In Greater Kailash - I Women Seeking Men
08448380779 Call Girls In Greater Kailash - I Women Seeking MenDelhi Call girls
 
Automating Business Process via MuleSoft Composer | Bangalore MuleSoft Meetup...
Automating Business Process via MuleSoft Composer | Bangalore MuleSoft Meetup...Automating Business Process via MuleSoft Composer | Bangalore MuleSoft Meetup...
Automating Business Process via MuleSoft Composer | Bangalore MuleSoft Meetup...shyamraj55
 
Pigging Solutions in Pet Food Manufacturing
Pigging Solutions in Pet Food ManufacturingPigging Solutions in Pet Food Manufacturing
Pigging Solutions in Pet Food ManufacturingPigging Solutions
 
SQL Database Design For Developers at php[tek] 2024
SQL Database Design For Developers at php[tek] 2024SQL Database Design For Developers at php[tek] 2024
SQL Database Design For Developers at php[tek] 2024Scott Keck-Warren
 
Presentation on how to chat with PDF using ChatGPT code interpreter
Presentation on how to chat with PDF using ChatGPT code interpreterPresentation on how to chat with PDF using ChatGPT code interpreter
Presentation on how to chat with PDF using ChatGPT code interpreternaman860154
 
08448380779 Call Girls In Friends Colony Women Seeking Men
08448380779 Call Girls In Friends Colony Women Seeking Men08448380779 Call Girls In Friends Colony Women Seeking Men
08448380779 Call Girls In Friends Colony Women Seeking MenDelhi Call girls
 
How to Troubleshoot Apps for the Modern Connected Worker
How to Troubleshoot Apps for the Modern Connected WorkerHow to Troubleshoot Apps for the Modern Connected Worker
How to Troubleshoot Apps for the Modern Connected WorkerThousandEyes
 
Salesforce Community Group Quito, Salesforce 101
Salesforce Community Group Quito, Salesforce 101Salesforce Community Group Quito, Salesforce 101
Salesforce Community Group Quito, Salesforce 101Paola De la Torre
 
08448380779 Call Girls In Civil Lines Women Seeking Men
08448380779 Call Girls In Civil Lines Women Seeking Men08448380779 Call Girls In Civil Lines Women Seeking Men
08448380779 Call Girls In Civil Lines Women Seeking MenDelhi Call girls
 
Slack Application Development 101 Slides
Slack Application Development 101 SlidesSlack Application Development 101 Slides
Slack Application Development 101 Slidespraypatel2
 
Swan(sea) Song – personal research during my six years at Swansea ... and bey...
Swan(sea) Song – personal research during my six years at Swansea ... and bey...Swan(sea) Song – personal research during my six years at Swansea ... and bey...
Swan(sea) Song – personal research during my six years at Swansea ... and bey...Alan Dix
 
Handwritten Text Recognition for manuscripts and early printed texts
Handwritten Text Recognition for manuscripts and early printed textsHandwritten Text Recognition for manuscripts and early printed texts
Handwritten Text Recognition for manuscripts and early printed textsMaria Levchenko
 

Kürzlich hochgeladen (20)

From Event to Action: Accelerate Your Decision Making with Real-Time Automation
From Event to Action: Accelerate Your Decision Making with Real-Time AutomationFrom Event to Action: Accelerate Your Decision Making with Real-Time Automation
From Event to Action: Accelerate Your Decision Making with Real-Time Automation
 
AI as an Interface for Commercial Buildings
AI as an Interface for Commercial BuildingsAI as an Interface for Commercial Buildings
AI as an Interface for Commercial Buildings
 
[2024]Digital Global Overview Report 2024 Meltwater.pdf
[2024]Digital Global Overview Report 2024 Meltwater.pdf[2024]Digital Global Overview Report 2024 Meltwater.pdf
[2024]Digital Global Overview Report 2024 Meltwater.pdf
 
The 7 Things I Know About Cyber Security After 25 Years | April 2024
The 7 Things I Know About Cyber Security After 25 Years | April 2024The 7 Things I Know About Cyber Security After 25 Years | April 2024
The 7 Things I Know About Cyber Security After 25 Years | April 2024
 
IAC 2024 - IA Fast Track to Search Focused AI Solutions
IAC 2024 - IA Fast Track to Search Focused AI SolutionsIAC 2024 - IA Fast Track to Search Focused AI Solutions
IAC 2024 - IA Fast Track to Search Focused AI Solutions
 
Kotlin Multiplatform & Compose Multiplatform - Starter kit for pragmatics
Kotlin Multiplatform & Compose Multiplatform - Starter kit for pragmaticsKotlin Multiplatform & Compose Multiplatform - Starter kit for pragmatics
Kotlin Multiplatform & Compose Multiplatform - Starter kit for pragmatics
 
Azure Monitor & Application Insight to monitor Infrastructure & Application
Azure Monitor & Application Insight to monitor Infrastructure & ApplicationAzure Monitor & Application Insight to monitor Infrastructure & Application
Azure Monitor & Application Insight to monitor Infrastructure & Application
 
Tech-Forward - Achieving Business Readiness For Copilot in Microsoft 365
Tech-Forward - Achieving Business Readiness For Copilot in Microsoft 365Tech-Forward - Achieving Business Readiness For Copilot in Microsoft 365
Tech-Forward - Achieving Business Readiness For Copilot in Microsoft 365
 
08448380779 Call Girls In Greater Kailash - I Women Seeking Men
08448380779 Call Girls In Greater Kailash - I Women Seeking Men08448380779 Call Girls In Greater Kailash - I Women Seeking Men
08448380779 Call Girls In Greater Kailash - I Women Seeking Men
 
Automating Business Process via MuleSoft Composer | Bangalore MuleSoft Meetup...
Automating Business Process via MuleSoft Composer | Bangalore MuleSoft Meetup...Automating Business Process via MuleSoft Composer | Bangalore MuleSoft Meetup...
Automating Business Process via MuleSoft Composer | Bangalore MuleSoft Meetup...
 
Pigging Solutions in Pet Food Manufacturing
Pigging Solutions in Pet Food ManufacturingPigging Solutions in Pet Food Manufacturing
Pigging Solutions in Pet Food Manufacturing
 
SQL Database Design For Developers at php[tek] 2024
SQL Database Design For Developers at php[tek] 2024SQL Database Design For Developers at php[tek] 2024
SQL Database Design For Developers at php[tek] 2024
 
Presentation on how to chat with PDF using ChatGPT code interpreter
Presentation on how to chat with PDF using ChatGPT code interpreterPresentation on how to chat with PDF using ChatGPT code interpreter
Presentation on how to chat with PDF using ChatGPT code interpreter
 
08448380779 Call Girls In Friends Colony Women Seeking Men
08448380779 Call Girls In Friends Colony Women Seeking Men08448380779 Call Girls In Friends Colony Women Seeking Men
08448380779 Call Girls In Friends Colony Women Seeking Men
 
How to Troubleshoot Apps for the Modern Connected Worker
How to Troubleshoot Apps for the Modern Connected WorkerHow to Troubleshoot Apps for the Modern Connected Worker
How to Troubleshoot Apps for the Modern Connected Worker
 
Salesforce Community Group Quito, Salesforce 101
Salesforce Community Group Quito, Salesforce 101Salesforce Community Group Quito, Salesforce 101
Salesforce Community Group Quito, Salesforce 101
 
08448380779 Call Girls In Civil Lines Women Seeking Men
08448380779 Call Girls In Civil Lines Women Seeking Men08448380779 Call Girls In Civil Lines Women Seeking Men
08448380779 Call Girls In Civil Lines Women Seeking Men
 
Slack Application Development 101 Slides
Slack Application Development 101 SlidesSlack Application Development 101 Slides
Slack Application Development 101 Slides
 
Swan(sea) Song – personal research during my six years at Swansea ... and bey...
Swan(sea) Song – personal research during my six years at Swansea ... and bey...Swan(sea) Song – personal research during my six years at Swansea ... and bey...
Swan(sea) Song – personal research during my six years at Swansea ... and bey...
 
Handwritten Text Recognition for manuscripts and early printed texts
Handwritten Text Recognition for manuscripts and early printed textsHandwritten Text Recognition for manuscripts and early printed texts
Handwritten Text Recognition for manuscripts and early printed texts
 

Rg58 s par theory cst_spice_dws_final

  • 1. Comparison of time-domain Sparameters of RG58 cable computed by: Theory, CST, SPICE, DWS S. Caniggia, P. Belforte February 04, 2014 1
  • 2. Outline • • • • • • • • • Introduction S-parameter definition in time domain Simulations of a 18.3-cm RG58 coaxial cable S11&S21 computed by analytic approach (theory) Cable Studio 2013 results as source of a BTM of a 1.83m RG58 coaxial cable used in DWS Analytical method results as source of a BTM of a 10-m RG58 coaxial cable used in DWS Conclusions Appendix: Dielectric losses (Tanδ) References 2
  • 3. Introduction • • • • • • In this report, the sixth of a series devoted to lossy lines [1,2,3,7,8], several approaches for computing time-domain step responses of a lossy line are outlined and compared. The methods used are: MWS of CST, CS of CST, RL-TL model for SPICE & DWS, Theory. The purpose is to pinpoint the advantages and drawbacks of each approach for simulating lossy lines. The feasibility of deriving BTM models to be used by DWS is analyzed. Long lossy lines can be simulated by DWS in seconds using a cascade of shorter line segment characterized as Behavior Transmission Model (BTM) by parameters S11 & S21 in time domain (7,9). These S parameters can be computed by CS or theory and can be used as models for DWS. If a piecewise linear (pwl) approximation is used for behaviors, a dramatic speedup of simulations can be obtained A typical RG58 coaxial cable is used as line sample for the study.
  • 4. Methods for time domain simulations of lossy lines [4] Three methods can be used to simulate lossy lines in transient. The choice depends on which simulator should be used for a simple or complex line structure. 1. Behavioral Transmission line Model (BTM) block, based on time-domain step responses of lossy line S-parameter to be used within the Digital Wave Simulator (DWS) [1,2,3,7,8,9] to get quick simulations. 2. Vector fitting technique (VFT) [4,6] to set, starting from analytical expression of losses, an equivalent circuit for a cascade of RLGC-TL (lossless) segments of line electrically short to be used with a SPICE-like circuit simulator such as MC10 [1,2,3,4,6] or DWS for faster (1-2 order of magnitude) simulations [1,2,3,7,8] . 3. Model Order Reduction (MOR) technique to set, starting from S parameters, an equivalent circuit of the line (complex net of RLGC-TL) for the frequency range of interest to be used by CST circuit simulator [1,2,3,7,9]. Note: • The lossy line can be both a cable or a PCB trace. • VTF and MOR should be used for the frequency range of interest. • CST is particularly suitable for complex line structures such as multi-conductor lines with shields. • DWS allows the use of hybrid BTM and circuital models [8]
  • 5. Flow chart for direct transient simulation of lossy lines by using three different methods: SPICE, CST, DWS [4]. Define the line (a,p,σ,μ,Rdc,tanθ,Kp) and compute the per-unit-line parameters: Zi, L0, C0, Gd unit cell RL TL Segmented line Full line Which model ? GC One block: measured or computed S-parameter line in time domain S11 One block complex RLGC-TL net Zi, L0,C0, Gd VFT technique Modeling Cascade of unit cells to form a block (SPICE-like Sim.) MOR technique S21 Which technique? S technique Modeling Modeling One RLGC-TL block One BTM block (DWS) (SPICE in CST) Cable block in schematic Simulated waveforms with several loadings (passive/active, linear/non-linear)
  • 7. S-parameter definition for two-port network [5] I1 a1 I2 + + Z01 b1 V1 Two port network - V2 - a2 b2 Z02 With n=1,2: Normalized incident wave Vn  an  Z0n Vn  (Vn   Vn - )  Z0n (a n  b n ) 1 1 In  (Vn   Vn - )  (a n  b n ) Z0n Z0n Vn  bn  Z0n Normalized reflected wave  b1  S11 S12   a1  b   S S22  a 2   2   21   7
  • 8. S-parameter physical interpretation [5] a1 a2=0 Z01 + Source applied to Port 1 - b1  S11a1 b 2  S21a1 a1  Port 2 matched Two port network b1 Z02 b2 S11 is just the input reflection coefficient when the output is matched. S21 is the ratio of waves to the right at output and input under this condition. V1  Z01I1 2 Z01 V1  Z01I1 b1  2 Z01 When Z01=Z02=Z0 (the characteristic impedance of the two port network representing a cable), and the source is a step of amplitude 2V: 1+S11 and S21 are the V1 and V2 voltages respectively. 8
  • 9. Port signals in MWS • • • • MWS stimulates the network by means of a gaussian pulse having a flat bandwidth up to the maximum frequency defined by the user. Port signals: (i1), (o1,1), (o2,1) of MWS have the meaning respectively of incident (a1), reflected wave at port1 (b1) and reflected wave at port2 (b2). Better results can be obtained by using waveguide ports instead of discrete ports when possible: less oscillations in reflected wave b1. To find equivalent circuit of a DUT it is better to use the option in MWS “S parameters without normalization to fixed impedance” instead of “…with…”: resonance peaks are avoided. These resonances are due to mismatch between port and waveguide which could be: coaxial cable, microstrip, etc. • Integrating (o1,1) & (o2,1) waveforms in time domain, we get the response at port1 (1+S11) and port2 (S21) of a step pulse with rise time tr determined by the maximum frequency. • The source pulse is obtained by integrating (i1) of MWS. 9
  • 10. S parameters in time domain Typical source and load voltage waveforms for an interconnect matched at both ends: lossless TL (dashed line), frequency-dependent lossy TL (solid line) [6, Fig.7.3] Definitions of S parameters in time domain: •VS=1+S11 •VL=S21 When TL has characteristic impedance different from the loads, distortions occur 10
  • 11. Simulations of a 18.3-cm RG58 coaxial cable 11
  • 12. S-parameters calculations • • • • • • Time-domain S-parameters computation from incident and reflected waves provided by MWS is shown. S11 and S21 time-domain step responses with matched line at both ends are computed integrating the waveforms provided by MWS when using waveguide ports. Comparison with RL-TL model used by MC10 (SPICE) or DWS [1,2,3] and 2D-TL model of Cable Studio (CS) [3] is given. CS 2013 takes into account also proximity effects [3]. The accuracy of models has been evaluated by comparison with actual TDR measurements of a 1.83-m RG58 coaxial cable [2,3,7,8]. The lack of dielectric losses in the RL-TL model is somewhat compensated by the overestimation of skin effect [3]. 12
  • 13. MWS structure •Frequency range: 0-40GHz •Waveguide ports Cable parameters: • Dielectric=2.3, tangent delta=0 • Lossy metal: 5.8e7 S/m • Geometry in mm: length=183; wire radius=0.395, shield radius=1.397; shield thickness=0.127 Meshcells=545,472 13
  • 14. Input signal in MWS Gaussian (40GHz) Step source Integration of gaussian normalized to maximum value of the integral Tr=23ps 14 Rise time tr between 10-90% is about 23ps as used in TDR measurements
  • 15. Port signals of RG58 in MWS i1 o21 ns o11 ns Integrating o11 and o21 and normalizing the results to the maximum value of the gaussian integral, we get respectively S11 and S21 as response of a step with tr=23 ps 15
  • 16. Cable studio (CS) structure Step source with 40GHz bandwidth imported from MWS (see previuos slide) Ohmic losses only 16
  • 17. MC10 (SPICE) structure The equivalent RL circuit was obtained by VFT applied to compact expressions for coaxial cable without factor ½, see Eq.7.57 of [6] Step source with tr=25ps S11=VTin S21=VTout Cascade of 100 1.83-mm unit RL-TL cell 17
  • 18. DWS (Spicy SWAN [12 ]) circuits RL-TL5mmx37=185mm 185-mm RG58 from CST 18
  • 19. Input (1+S11) and output (S21) line waveforms Line length= 18.3 cm 1+S11 S21 MWS waveforms ps Remark: MC10 and CS provide similar waveforms 19
  • 20. S11 Volt MC10&DWS MWS: solid CS: dot MWS&CS MC10: dash ps • MC10 & DWS with RL-TL cells compute the same waveforms [10] • MWS & CS provide about similar waveforms with less losses (lower values than DWS & MC10) 20
  • 21. 1+S11 and S21 Volt 1+S11 MC10 MWS: solid MWS&CS CS: dot MC10: dash MWS&CS MC10 S21 DWS 1+S11 ps • MC10 & DWS compute the same waveforms [10] • MWS & CS compute similar waveforms with about half losses S21 • S11 of CS & DWS show some slight segmentation due to 37cell discretization 21
  • 22. 1+S11 and S21 with and without dielectric losses MC10 CS CS MC10 •Solid MC10 RLTL without dielectric losses •Dash CS 2013 without dielectric losses •Dot CS 2013 with dielectric losses (Tanδ=0.8m) Dielectric losses introduce just a slight difference in this portion of the waveform 22
  • 23. CS 2012: Adding dielectric losses (tanδ=0.8m) Volt Ohmic losses 1+S11 S21 sec Volt Ohmic + dielectric losses 1+S11 S21 sec •There are slight differences in this portion of the waveform •The segmentation effect is eliminated 23
  • 24. CS 2013: Adding dielectric losses (tanδ=0.8m) Volt Ohmic losses 1+S11 S21 sec Volt Ohmic + dielectric losses 1+S11 •The segmentation effect is eliminated also for ohmic losses • There is a slight increase of losses due to proximity effect in CST 2013 vs 2012 S21 sec 24
  • 25. Input and output line voltages VS VL MC10 VS VL MWS 2013 VS VL CS 2013 •For MC10 a ramp has been used •For MWS and CS the time integral of a gaussian (40GHz BW) has been used. • S11 (=Vin-1) and S21 (=Vout) should be computed with an input step of about 1ps rise time to approximate the ideal step response. • A non zero rise time input could give some inaccuracy when using these responses to get a BTM model [11]. • In the following slides this error 25 will be estimated.
  • 26. Comments on simulations • • • • • • MC10 & DWS by using RL-TL model compute the same waveforms and are used as reference being validated experimentally [1,2,3]. MWS & CS provide similar waveforms with less losses respect to RL-TL model, as verified in [1,2]. MWS waveforms evolves more rapidly than CS towards dc values for high values of time. S11 of DWS shows a small ringing due to finite number of cell segmentation. This effect can be eliminated by using more unit cells (example 100 as done with MC10). DWS simulations are very fast (50+ times faster than MC 10) at equal cell number. 26
  • 27. S11&S21 computed by analytic approach (Theory)
  • 28. Analytic method • • • • • • The method used for computing S11 & S21 in time domain is outlined in [4] and with more details in chapter 7, subparagraph 7.1.5.2 of [6]. A linear ramp of tr=25ps for a cable length of 18.3cm and tr=100ps for 1.83m are used as input . Tangent delta (θo) is set to 0.8m, see Appendix. Skin effect is computed by Eq.7.57 of [6] by using a factor ½ for comparison with CS and without the factor ½ for comparison with RL-TL model. MathCad code professional 2001i is used for analytic computations. The comparisons are performed among: RL-TL model (RL-TL), Cable Studio ohmic losses (cs), Cable Studio ohmic+dielectric losses (cs_d), analytic results with all losses (Theory).
  • 29. Line structure & input signal Source signal: tr=25ps Zocoax Vsin (1+S11) Len Vl (S21) Vs=2V Zocoax tr (10%-90%) Coaxial cable rw: wire radius rsh : internal shield radius dcoax: shield thickness
  • 30. Skin effect (compact expressions) ½ factor • In [5], Ziwcoaxb and Zishcoaxb expressions for a coaxial cable, are reported without the factor ½, while for a round wire the factor ½ should be used. •It will be shown that cs waveforms are in agreement with theory using factor ½ (round wire) while RL-TL waveforms are in agreement with theory without factor ½ because vector fitting technique (VFT) was applied starting from these expressions.
  • 31. Skin effect impedances (Ohm/m) •ZiSkinw Internal wire impedance computed as round wire, see chapter 7 of [6] for the expressions. •Ziwcoaxb Internal wire impedance computed by compact expression with ½ factor. •Zishcoaxb Shield impedance computed by compact expression with ½ factor. • ZiSkin= Ziwcoaxb+ Zishcoaxb Total impedance of the cable ZiSkinw and Ziwcoaxb provide the same values See also the results reported in [3] for the 18.3cm RG58 cable
  • 32. Dielectric losses and line parameters Dielectric losses Line parametrs For more details, see chapter 7 of [6]
  • 33. Output rise time comparison (Len=18.3cm) MC, CS, CS_d ps Theory ns • Good agreement nevertheless a ramp and not a gaussian shape has been used • A delay of 22ps has been introduced into theorical result for comparison reasons
  • 34. S11&S21 computed with factor ½ (Len=18.3cm) cs_d cs_d Theory • Good agreement between cs_d and theory • S11 of theory is slightly lower
  • 35. S11&S21 computed without factor ½ (Len=18.3cm) •Very good agreement between RL-TL model and theory RL-TL RL-TL ps Theory ns •The reason is that the RL-TL model was obtained by VFT using compact skin effect expressions for coaxial cable without factor ½.
  • 36. S11 computed with factor ½ (Len=1.83m) Theory Cable studio (Bandwith=10GHz) CST provides slightly lower values
  • 37. S21 computed with factor ½ (Len=1.83m) Theory Both methods provide the same values Cable studio (Bandwith=10GHz)
  • 38. 1+S11 computed without factor ½ (Len=1.83m) Theory Cable studio (Bandwith=10GHz) Theory provides more than doubled values for S11
  • 39. S21 computed without factor ½ (Len=1.83m) Theory Theory computes slight lower rising edge values Cable studio after the 80% of its DC level (Bandwith=10GHz)
  • 40. Comments on analytic approach • • • • Good agreement between CS and theory waveforms considering all losses. RL-TL model overestimates the losses due to the lack of .5 factor in skin effect compact expressions used to get the equivalent RL circuit by Vector Fitting Technique. This difference compensates the lack of dielectric losses in the model RL-TL and justifies the good agreement with the measured waveform tails as shown in [2,3]. The S21 rising edge coming from the RL-TL model is too fast due to lack of dielectric losses and can be compensated using a DWS RL_LTL hybrid model as shown in [8]
  • 41. Cable Studio results as source of a BTM of a 1.83-m RG58 coaxial cable used in DWS 41
  • 42. Used BTM procedure • • • • The S11 and S21 computed by cable studio (CS) 2013 for a 18.3cm of RG58 (0-40GHz) have been used as sources to get the Behavioral Transmission Model (BTM) in DWS. The waveforms obtained from a 1ps ramp input are used in the BTM model as PWL approximations and not directly as ASCII file (both ways provided by DWS) to speed up the simulations . For comparisons, a ramp of 25ps is also considered. DWS has been used to compute VS&VL voltages obtained from a cascade of 10 BTM with a ramp input. The waveforms are compared with those computed by CS 2013 using a model valid in the range 010GHz.
  • 43. CS VS&VL (cable length=18.3cm, model:040GHz,tandelta=0.0) tr=25ps 1+S11 A fixed time step of 0.1ps has been used for CS simulation tasks tr=1ps 1+S11 S21 S-parameter waveforms do not seem influenced by the tr, apart the oscillations in S11 43
  • 44. CS VS&VL (cable length=18.3cm, model:040GHz,tandelta=0.8m) tr=25ps 1+S11 A fixed time step of 0.1ps has been used S21 tr=1ps 1+S11 S21 S11 waveform does not seem influenced by the tr, apart the oscillations in S11 44
  • 45. VS&VL (cable length=18.3cm, model:040GHz,tandelta=0.8m): extended time scale 1+S11 tr=25ps S21 Time step=1ps Samples=4001 Zoom 45
  • 46. VL edge detail (cable length=18.3cm, model:040GHz,tandelta=0.8m) tr=25ps S21 Time step=0.1ps Samples= 4001 tr=1ps S21 Time step=0.02ps Samples= 8001 •S21 rising edge is strongly influenced by input tr • Waveform from 1ps stimulus can be used to extract BTM models using 46 the PWL technique
  • 47. PWL generation PWL generation: The CS output waveform is digitized by extracting the time and amplitude values at user chosen points (see small circles along the waveform). The manual choice is performed with the aim of minimizing the number of points but still achieving a good accuracy .This can been accomplished by a graphic digitizer program due to the availability of the image files. In case of ASCII files compatible with the .g format of DWS, a DWV viewer feature is provided to quickly accomplish this task in a semi-automatic way.
  • 48. VS&VL (cable length=1.83m, model:0-10GHz, tandelta=0.8m, tr=25ps) V 1+S11 CS 2013 Cascade of 10 BTM cells with DWS S21 ns V 1+S11 S11 & S21 waveforms are in good agreement ns 48
  • 49. VL (S21) edge detail (cable length=1.83m, model:010GHz, tandelta=0.8m, tr=25ps) V CS 2013 S21 Cascade of 10 BTM cells with DWS ns • S21 waveforms are in good agreement • S21 rising edge computed by 10 BTM seems to be a little lower 49
  • 50. Comments on BTM results • The S11 waveform obtained by DWS from a chain of 10 BTM cells derived from CS is in good agreement with the one obtained by CS for the total length of the cable The S21 edge obtained by a cascade of 10 BTM cells seems to be slightly faster than the one obtained by a CS for the total length of cable There are some key points to be taken into account in using the cascade of BTM cells : • • 1. 2. 3 4 A fast (1ps) edge has to be used as input stimulus to extract the BTM model of the unit cell. A slower rise time stimulus as 25ps would introduce a significant error in computing the S21 edge [11]. A suitable bandwidth (e.g. 40Ghz) has to be set in CS to get an accurate response to the 1ps input required for the BTM model. This bandwidth determines the number of cascaded RLCTL cells of the CS circuital model (100-cell for a 183mm long cable) and the simulation time of CS. BTM model accuracy depends on the number and placement of the breakpoints chosen for the pwl behavior. Normally 20-30 breakpoints are enough to get a good speed/accuracy trade off. An impressive DWS vs speedup factor (3 to 4 orders of magnitude) is obtained for “long” cables using chain of BTM cells
  • 51. Analytical methods used to extract a 1-m unit cell BTM to simulate a 10-m RG58 coaxial cable with DWS
  • 52. Procedure adopted for BTM cell extraction • • • The theoretical expressions previously shown in this report are used to get approximated S11 and S21 step responses for a 1-m RG58 cable. Two different ramps of tr=5ps and tr=25ps respectively are used as input stimuli. The computed waveforms are digitized to get the breakpoints for build up the pwl BTM cell model A chain of 10 equal cells is simulated by DWS to get the response of a 10-meter cable.
  • 53. Signals & line voltages for 1-m of RG58 Tr=25p s S21 Data used as input for BTM S11 Tp Data used as input for BTM Time period Tp should be large enough to reach with approximation the dc values of S11
  • 54. Signals & line voltages for 10-m of RG58 Source signal: tr=100ps Line voltages: input (vsin) & output (vl) Tp Time period Tp should be large enough to reach with approximation the dc values of S11
  • 55. S21 (vl) rising edge (10-m cable) Edge computed by Theory Edge computed by DWS using 10 BTM cells with tr=5ps Edge computed by DWS using 10 BTM cells with tr=25ps
  • 56. S21 (vl) rising edge of a 10-m cable: detailed view with equalized delays for edge comparison Edge computed by Theory Edge computed by DWS using 10 BTM cells with tr=5ps Edge computed by DWS using 10 BTM cells with tr=25ps As expected [11], better agreement is obtained by using tr=5ps as input for the 1m basic cell
  • 57. S11 reflections computed by Theory reflections computed by DWS by using 10 BTM with tr=5ps The difference after t=40ns is due to S11 behavior truncation after the first 40ns window. Beyond 40ns the analytical S11 response was not available due to FFT issues. At least a 400ns window should be required.
  • 58. BTM model from theoretical responses: key points 1. 2. 3. As for the BTM model extracted from Cable Studio simulations, some key points have to be pointed out: The S21 rising edge should be computed by IFFT using an enough short rise-time ramp as input (e.g. 5ps for 1-m cable) to limit the rise time error of the BTM cells cascade [11]. The reflection coefficient (S11) should be computed using an input stimulus period enough large to allow a good approximation of steady state (dc ) values. A tradeoff between this period and IFFT computation time is required. Therefore, a global tradeoff is needed to take into account accuracy requirement for simulations, fast tr, and large period Tp for IFFT computation. The BTM model extracted taking into account previous points is very fast and achieves a good accuracy level.
  • 59. Using Cable Studio: user considerations • • • • • • • • • • The results of CS are strongly influenced by several options set by the user. The effect of options on final results is not always clear to the user. TLM (modal) option is required to get accurate results. TLM produces circuital models including thousands of RLC and TL elements. The unit cell TL delay can be a number like TD=9.54361271247e-012 sec. This kind of values requires to set short fixed time step (e.g. 100fs) to get reliable results from CS simulations . Otherwise overall delay and behavior of a 100-cell cascade can be strongly affected. The Bandwidth to be set to get the modal TLM directly affects the number of cascaded cells in the cable model . For example a 40Ghz BW generates a 100-cell model for a 18.3 cm cable. CS 2013/14 simulations at fixed step can require several minute on a multicore CPU. DWS can achieve a 10-50X speed up over CS to simulate complex TLM models generated by CS [13 ]. To extract accurate BTM models for DWS, a rise time of about 1ps for a 20-cm unit cell and 5ps for a 1-m unit cell is suggested as stimulus signal of the cable. The same rule of thumb should be utilized to extract BTM models from analytical methods. 59
  • 60. Conclusions • • • • • • • • Cable Studio computes the step responses of the cable in good agreement with MWS and the analytic approach based on theory. RL-TL circuital model provides overestimation of losses because the VFT used for getting the equivalent RL circuit was applied by using compact analytic expression for coaxial cable without the factor ½ [6]. This factor compensates the lack of dielectric losses in the RL-TL model with the exception of S21 rising edge. A closer result with the measurement is shown in [2] and [3]. An improved RL-TL hybrid circuital-BTM model is shown in [8]. A BTM cell model cannot be practically obtained by a 3D model (MWS) because the number of mesh cells required by a source with rise time in the order of 1 ps is too large for the computation. A BTM cell can be obtained by a 2D model (CS) feasible with a good tradeoff between the CS input bandwidth and the stimulus rise time. The analytical approach is feasible to get the BTM model. A tradeoff is needed between the required fast input rise time and large period value used for the IFFT computation. A two-step modeling using two different theoretical responses (fast edge & short period, slower edge & larger period) should give the best results DWS can be used with major speed benefits both for TLM (10 to 50X) and BTM (up to 10000X) cable models DWS can also utilize both hybrid ( BTM and TLM) and full BTM models directly extracted or optimized to actual TDR measures [8]. 60
  • 62. Typical Tanδ values • The following tables are extracted from the literature. • They should be compared with the value of Tanδ=0.8m used in this report.
  • 63. Tandδ http://cp.literature.agilent.com/litweb/pdf/genesys200801/elements/substrate_tables/t ablelosstan.htm The dielectric loss tangents for some materials commonly used in coaxial cables are: tanD at 100 MHz tanD at 3 GHz Air 0.0 0.0 PTFE 2E-4 15E-4 PolyEthylene, DE-3401 2E-4 3.1E-4 Polyolefin, irradiated 3E-4 3E-4 Polystyrene 1E-4 3.3E-4 Polyvinal formal (Formvar) 1.3E-2 1.1E-2 Nylon 2E-2 1.2E-2 Quartz, fused 2E-4 6E-5 Pyrex Glass 3E-3 5.4E-3 Water, distilled 5E-3 1.6E-1 Material For simulation we have used Tanδ=8e-4 (used in CST as default value) 63
  • 64. Tandδ (coax Belden) For RG58, a tanδ between 1.12e-3 and 2.12e-3 are given (values higher than the previous table for polyethylene) Tandelta From: H. Johnson, M. Graham, “High-Speed Signal Propagation”, Prentice Hall, 2003 64
  • 65. References [1] Piero Belforte, Spartaco Caniggia, “CST coaxial cable models for SI simulations: a comparative study”, March 24th 2013CST models for theRG58 coax cable [2] Piero Belforte, Spartaco Caniggia,, “Measurements and Simulations with1.83-m RG58 cable”, April 5th 2013 [3] Piero Belforte, Spartaco Caniggia, “TDR measurements and simulations of RGU 58 coaxial cable S-parameters”, June 04, 2013 TDR measures and simulations of RG58 cable [4] Spartaco Caniggia, “Modeling interconnects and power distribution network in PCBs, CST workshops, Milano, 26-11-2013 [5] Ramo, Whinnery, Van Duzer, “Fields and wave in communication electronics”, John Wiley, 3rd Edition [6] S. Caniggia, F. Maradei, “Signal Integrity and Radiated Emission of High-Speed Digital Systems”, John Wiley & Sons, 2008 65
  • 66. References (2) [7] Piero Belforte “ TDR mesurements of RG58 coaxial cable Sparameters”, April11th 2013 TDR measurements of RG58 coax cable [8] Piero Belforte “ RG58 coaxial cable: A comparison among Analytical models, DWS BTM models, TDR measures and CST 2013 Cable Studio simulations”, Dec. 24th 2013 Models and measurements for a RG58 coax [9] Piero Belforte “A new modeling and simulation environment for highperformance digital systems” HP Digital Symposium (1993) [10] Piero Belforte “DWS vs MC10: a comparative benchmark” April 15th 2013 DWS vs MC10 [11] Piero Belforte “ Prediction of rise time errors of a cascade of equal behavioral cells” May 2nd 2013 Rise time error prediction [12] http://ischematics.com/ [13] SWAN sim of a CST2014 TLM cable model 66