Transmission wave guide lines

1. INTRODUCTION
Transmission Lines and Waveguides

2. Energy Transfer
All the systems are designed to carryout the
following jobs:
1.Energy generation.
2. Energy transportation.
3. Energy consumption.
Here we are concerned with energy transfer.

3. Electrons
Electron is part of everything on earth. Electrons
are the driving force for every activity on earth.
Electron is a energy packet, Source of energy,
capable of doing any work.
Electron accumulation = Voltage
Electron flow = current
Electrons’ oscillation = Wave
Electron transfer = Light
Electron emission = Heat.

4. No mass ;
No inertia;
Highly mobile;
No wear and tear;
No splitting of
electron;
No shortage;
Excellent service
under wider
different conditions:
Vacuum, gas, solid;

5. Controlled by
Fields :
accelerated,
retarded, change
directions,
increase and
decrease of stream
of electrons;
instant reaction
due to zero inertia.

6. Energy = Electron - Wave
Energy is transferred from place to by two
means:
1.Current : Flow of electrons through
conductors.
2. Wave : Wave propagation in space, using
guiding systems or unguided system (free
space).
In this subject, except free space energy
transfer, other means are discussed.

7. Electron - waves

8. Major Topics for discussion
i) Circuit domain ( Filters )
i) Semi Field domain (Transmission Line : Voltage-
Current – Fields)
i) More Field domain (Coaxial line)
i) Field domain : TEM waves ( Parallel plate guiding)
i) Fully Field domain : TE-TM modes ( Waveguide )

14. Transmission Line – Waveguide
Guided communication

37. System Frequency Energy Flow
Circuits LF, MF, HF Inside Conductor
Transmission Lines VHF Outside Cond.
Coaxial Lines UHF Outside Cond.
Waveguides SHF inside Cond.
Optical Fiber 1015 Hz Inside Fiber

38. Energy
V = Voltage = Size of energy packet / electron.
I = Current = Number of energy packet flow / sec
Total energy flow / sec = V X I

39. System Power Flow Medium
Circuits P = V x I Conductor
Transmission Lines P = E x H Free space
Coaxial Lines P = E x H Free space
Waveguides P = E x H Free space
Optical Fiber P = E x H Glass

40. Quantum of energy E = h f; h =6.626x10-34 J-s
Quantum physics states the EM waves are
composed of packets of energy called photons.
At high frequencies each photon has more energy.
Photons of infrared, visible, and higher frequencies
have enough energy to affect the vibrational and
rotational states of molecules and electrons in the
orbits of atoms in the materials.
Photons at radio waves do not have enough energy
to affect the bound electrons in the materials.

41. System Energy Flow
Circuits Inside Conductor
Transmission Lines TEM mode
Coaxial Lines TEM mode
Waveguides TE and TM modes
Optical Fiber TE and TM modes

42. High Frequency Effects
1.Skin effect
2.Transit time –
3.Moving electron induce current
4. Delay
5. Retardation-.Radiation
6.Phase reversal of fields.
7.Displacement current.
8.Cavity

43. High Frequency effects
1.Fields inside the conductor is zero.
2.Energy radiates from the conductors.
3.Conductor no longer behaves as simple
conductor with R=0
4.Conductor offers R, L, G, C along its length.
5.Signal gets delayed or phase shifted.

44. Skin Effect
Skin effect makes the current flow simply a surface
phenomenon. No current that vary with time can
penetrate a perfect conducting medium. Iac = 0
The penetration of Electric field into the conducting
medium is zero because of induced voltage effect.
Thus inside the perfect conductor E = 0
The penetration of magnetic field into the conducting
medium is zero since current exists only at the
surface. H=0.

45. Circuits Radiate at high
frequency opearation
D →λ

46. Skin Effect
As frequency increases, current flow becomes a
surface phenomenon.

47. Conductor radiates at high frequencies