Part 1 covers RF signal behavior, wireless systems hardware and wireless systems operation

1. A man pushing his car stopped outside a hotel. As
soon as he got there he knew he was bankrupt. Why?

2. A man pushing his car stopped outside a hotel. As
soon as he got there he knew he was bankrupt. Why?

3. Carl Weisman’s
Introduction to RF & Wireless
Two Day Seminar
Module 1

4. Course Objectives
Explain
♦ RF signal behavior
♦ System hardware makeup
♦ Wireless systems’ operation
Communicate
♦ Using over 300 terms
Have Fun

5. Daily Schedule
8:30 am – 10: 00 am Fun
10:00 am – 10:15 am Break
10:15 am – 11:45 am Fun
Noon – 1:00 pm Lunch
1:00 pm – 2:30 pm Fun
2:30 pm – 2:45 pm Break
2:45 pm – 4:15 pm Fun

6. Course Agenda
Day One
• Morning (Module 1)
– Introduction to RF
• Afternoon (Module 2)
– RF hardware
Day Two
• Morning (Module 3)
– Older systems & mobile telephony
• Afternoon (Module 4)
– Newer systems & the future

7. Module 1 - Introduction To RF
1. The Basics
2. RF Behavior
3. Modulation
4. Noise

8. Module 1
1. The Basics
2. RF Behavior
3. Modulation
4. Noise

9. 1. The Basics
Vocabulary
Transmitters & Receivers
Signals

10. 1. The Basics
Vocabulary
Transmitters & Receivers
Signals

11. Vocabulary
Electronics Terms
♦ Voltage: A potential between 2 points (Volts)
♦ Current: A flow of electrons (Amps)
♦ Power = Voltage x Current (Watts)
♦ Energy = Power x Time (Watt-hours)
♦ AC: Varies with time (e.g., wall outlet)
♦ DC: Constant (e.g. flashlight battery)
The Basics - Vocabulary

12. Vocabulary
More Electronics Terms
♦ Signal: Electrical energy made to vary in a
predetermined way
♦ Device: An electronic gadget that is indivisible
♦ Component: Same as a device
♦ Circuit: A collection of interconnected devices
♦ RF: Radio Frequency
♦ Wireless: A marketing term
The Basics - Vocabulary

13. Vocabulary
Prefixes
♦ pico: trillionth 10-12 0.000000000001
♦ nano: billionth 10-9 0.000000001
♦ micro: millionth 10-6 0.000001
♦ milli: thousandth 10-3 0.001
♦ Kilo: thousand 103 1000
♦ Mega: million 106 1000000
♦ Giga: billion 109 1000000000
The Basics - Vocabulary

14. Mu Not Moo
µ
The Basics - Vocabulary

15. 1. The Basics
Vocabulary
Transmitters & Receivers
Signals

16. Transmitters & Receivers
An Interesting Thing To Know
♦ An electrical signal can move from place to
place two different ways:
1) As current on a conductor (e.g. a wire)
2) As invisible waves in the air
The Basics - Transmitters & Receivers

17. Transmitters & Receivers
Wireless Communications
The Basics - Transmitters & Receivers

18. Transmitters & Receivers
Wireless Communications
The Basics - Transmitters & Receivers

19. Transmitters & Receivers
Wireless Communications
Transceiver
The Basics - Transmitters & Receivers

20. 1. The Basics
Vocabulary
Transmitters & Receivers
Signals

21. Signals
There Are Two Kinds Of Signals
♦ Analog: Can take any value
♦ Digital: Can take one of two values (high, low)
The Basics - Signals

22. Analog Signals
A Very Special Analog Signal
♦ Sine wave:
The Basics - Signals

23. Analog Signals
Properties Of A Sine Wave
Speed
The Basics - Signals

24. Analog Signals
Properties Of A Sine Wave
Speed
Frequency
The Basics - Signals

25. Analog Signals
Properties Of A Sine Wave
Speed
Frequency
(Hertz)
The Basics - Signals

26. Analog Signals
Properties Of A Sine Wave
Speed
Amplitude
Frequency
(Hertz)
The Basics - Signals

27. Analog Signals
Properties Of A Sine Wave
Speed
Amplitude
Frequency
(Hertz)
Wavelength

28. Analog Signals
Properties Of A Sine Wave
90º Phase
Speed
Amplitude 360º
0º 180º Frequency
(Hertz)
270º
Wavelength

29. Analog Signals
A Special Relationship
♦ Frequency x Wavelength = Constant
∴When you know one you know the other
♦ The constant is usually the speed of light
The Basics - Signals

30. Visual Depiction
High frequency =
Many waves
Occurring frequently
Close together
The Basics - Signals

31. Visual Depiction
Low frequency =
Few waves
Occurring infrequently
Far apart
The Basics - Signals

32. Analog Signals
What Makes Sine Waves Special?
♦ Every analog signal is just a summation of
multiple sine waves

33. Analog Signals
Why Is All Of This Important?
1) Because everything in the wireless world is
frequency dependent
• Components are specified over certain frequencies
• Applications are specified over certain frequencies
2) And because it is sine waves that travel through
the air as invisible waves
The Basics - Signals

34. Analog Signals
Frequency (Hertz) Application
Frequencies
60 Electrical wall outlet
Of 2,000 The human voice
Some 530,000 AM radio
Applications 54,000,000 VHF television
88,000,000 FM radio
824,000,000 Cellular phones
1,850,000,000 PCS phones
11,700,000,000 DirectTV™

35. Analog Signals
Wavelength (meters) Application
Wavelengths 5,000,000 Electrical wall outlet
Of 152,500 The human voice
Some 566 AM radio
Applications 5 VHF television
3 FM radio
0.3 Cellular phones
0.1 PCS phones
0.02 DirectTV™

36. Analog Signals
Frequency Band Frequency Range
L-Band 1 – 2 GHz
Bands S-Band 2 – 4 GHz
C-Band 4 – 8 GHz
X-Band 8 – 12 GHz
K-Band 12 – 40 GHz
The Basics - Signals

37. Analog Signals
Term Frequency Range
Frequency
RF Frequency Less Than 1 GHz
Ranges Microwave Frequency Between 1 GHz & 40 GHz
Millimeter Wave Frequency Greater Than 40 GHz
The Basics - Signals

38. Digital Signals
An Example Of A Digital Signal
The Basics - Signals

39. Digital Signals
Properties Of A Digital Signal
Amplitude
(0 or 1)
The Basics - Signals

40. Digital Signals
Properties Of A Digital Signal
Amplitude
(0 or 1)
Frequency
The Basics - Signals

41. Digital Signals
Properties Of A Digital Signal
Amplitude
(0 or 1)
Frequency = Data Rate
The Basics - Signals

42. Digital Signals
Properties Of A Digital Signal
Amplitude
(0 or 1)
Frequency = Data Rate (bits/second)
The Basics - Signals

43. Analog vs Digital
Analog Signals
♦ Occur naturally
♦ Represent information AND
♦ Travel through the air as invisible waves
Digital Signals
♦ Are man made
♦ Represent information only

44. Analog to Digital Conversion
How Is It
Done?

45. Digital Data Rate
Human Voice
♦ Highest frequency = 4000 Hz
Sample Rate
♦ Twice the highest frequency = 8000 samples/sec
Granularity
♦ 8 bits/sample
Data Rate
♦ 8 (bits/sample) X 8000 (samples/sec) = 64 Kbps

46. Analog vs Digital
Analog Signals
♦ Advantages: Can travel wirelessly
♦ Disadvantages: Susceptible to noise
Digital Signals
♦ Advantages: Noise resistant, compression
♦ Disadvantages: Expensive RF hardware
The Basics - Signals

47. The Basics
The end

48. Module 1
1. The Basics
2. RF Behavior
3. Modulation
4. Noise

49. 2. RF Behavior
Loss & Gain
Decibels
Bandwidth
RF in the Environment
Match

50. 2. RF Behavior
Loss & Gain
Decibels
Bandwidth
RF in the Environment
Match

51. Energy Is Conserved

52. Devices
Two Types Heat
Power Supply
Gain
Heat
Loss

53. Loss & Gain
Vocabulary
♦ Gain: Also called amplification & power gain
♦ Loss: Also called insertion loss & attenuation
RF Behavior - Loss & Gain

54. Loss & Gain
Component Active Passive
Possibilities
Gain “Amplifier” Impossible
Loss Many Many
RF Behavior - Loss & Gain

55. Loss & Gain
Are Cumulative
Total gain = 100
RF Behavior - Loss & Gain

56. 2. RF Behavior
Loss & Gain
Decibels
Bandwidth
RF in the Environment
Match

57. Decibels
What's The Problem?
1000 Watts 0.000000000001 Watts
RF Behavior - Decibels

58. Decibels
Definition
Decibels = 10 x log10(Pout/Pin)
RF Behavior - Decibels

59. Decibels
The Basics
♦ Measure a change (e.g. output vs input)
♦ Bigger (i.e, gain), decibels are positive
♦ Smaller (i.e., loss) , decibels are negative
♦ Decibels are abbreviated "dB"
RF Behavior - Decibels

60. Decibels
The Only Math You'll Need To Know
♦ +3dB means 2 times bigger
♦ +10 dB means 10 times bigger
♦ -3dB means 2 times smaller
♦ -10 dB means 10 times smaller
♦ Add and subtract decibels only
RF Behavior - Decibels

61. Decibel Conversion
Examples
Change Factors Decibels
4000 2 x 2 x 10 x 10 x 10 3+3+10+10+10=36 dB
-4000 -36 dB
5000 10 x 10 x 10 x 10 ÷ 2 10+10+10+10-3=37 dB
8000 2 x 4000 36 dB + 3 dB = 39 dB
6000 37.5 dB ≈ 37. 78 dB
RF Behavior - Decibels

62. Summing Decibels
Recall From Before
Total gain = 100
RF Behavior - Decibels

63. Summing Decibels
Now With dB
10 dB 10 dB
Gain Gain
Total gain = 20 dB
RF Behavior - Decibels

64. Summing Decibels
One More Example
Total change = +19 dB
RF Behavior - Decibels

65. dBm
What Is It?
♦ A measure of power NOT change
In The RF World
♦ The "standard" unit of power is 1 milliwatt
Definition
♦ dBm = "dB above 1 milliwatt"
RF Behavior - Decibels

66. dBm
Example
Gain of device = 30 dB
"Change" Output of device = 30 dBm
"Power"
Output = 30 dB above 1 milliwatt = 30 dBm
RF Behavior - Decibels

67. dBm Conversion

68. dBm
Recall From Before
0 dBm 19 dBm
Input = 0 dBm = 1 milliwatt
Total change = +19 dB
Output = 19 dBm ≈ 100 milliwatts
RF Behavior - Decibels

69. dBm
Another Example
20 dBm 39 dBm
Input = 20 dBm = 100 milliwatt
Total change = +19 dB
Output = 39 dBm ≈ 10 watts
RF Behavior - Decibels

70. 2. RF Behavior
Loss & Gain
Decibels
Bandwidth
RF in the Environment
Match

71. Bandwidth
What Is It?
♦ A range of frequencies (in Hertz)
♦ Defined by the highest & lowest frequency
Where Is It Used?
♦ Components
♦ Wireless applications
RF Behavior - Bandwidth

72. Bandwidth
Example 1
An amplifier provides 30 dB of gain from 75 MHz to
125 MHz. What is its bandwidth?
Highest frequency = 125 MHz
Lowest frequency = 75 MHz
Difference = 50 MHz = Bandwidth
RF Behavior - Bandwidth

73. Bandwidth
Example 2
Cellular telephony in the US operates between 824 MHz
and 894 MHz. What is the bandwidth?
Highest frequency = 894 MHz
Lowest frequency = 824 MHz
Difference = 70 MHz = Bandwidth
RF Behavior - Bandwidth

74. Percentage Bandwidth (BW)
What Is It?
♦Another way to describe bandwidth
How To Calculate It (from previous example)
1. Bandwidth = 70 MHz
2. Ave frequency = (824 + 894)/2 = 859 MHz
3. %BW = 70 MHz/859 MHz x 100% = 8%
RF Behavior - Bandwidth

75. Bandwidth
Ways To Describe It
♦Narrowband: %BW < 50%
♦Wideband: %BW > 50%
♦Octave: Highest frequency = 2x lowest frequency
♦Decade: Highest frequency = 10x lowest frequency
RF Behavior - Bandwidth

76. 2. RF Behavior
Loss & Gain
Decibels
Bandwidth
RF in the Environment
Match

77. RF In The Environment
Free Space Loss
Skin Effect
Absorption
Reflection

78. RF In The Environment
Free Space Loss
Skin Effect
Absorption
Reflection

79. Free Space Loss
RF signals spread out as they travel through the air
Power density: Watts per square meter
RF Behavior - RF In The Environment

80. Free Space Loss (FSL)
Formula
FSL = A function of frequency & distance
FSL > 120 dB
RF Behavior - RF In The Environment

81. Free Space Loss
Recall From Before
1000 Watts
RF Behavior - RF In The Environment

82. Free Space Loss
Recall From Before
60 dBm
Free Space Loss = 120 dB
RF Behavior - RF In The Environment

83. Free Space Loss
Recall From Before
60 dBm
-120 dB
RF Behavior - RF In The Environment

84. Free Space Loss
Recall From Before
60 dBm
- 60 dBm
-120 dB
RF Behavior - RF In The Environment

85. Free Space Loss
Recall From Before
60 dBm
Free Space Loss = 120 dB
- 60 dBm
RF Behavior - RF In The Environment

86. RF In The Environment
Free Space Loss
Skin Effect
Absorption
Reflection

87. Skin Effect
What Is It?
♦ When an RF signal is on a conductor, it resides
only on the surface
Signal on the surface
No signal inside
RF Behavior - RF In The Environment

88. Skin Effect
What Is The Implication?
♦ RF signals can't penetrate conductors (e.g. metal)
∴Metal can be used to control airborne RF waves
RF Behavior - RF In The Environment

89. RF In The Environment
Free Space Loss
Skin Effect
Absorption
Reflection

90. Absorption
What Is It?
♦ When RF waves travel through the air, some
things they encounter cause attenuation
• Air
• Rain
• Foliage
RF Behavior - RF In The Environment

91. Absorption
And
♦ Absorbed energy gets converted to heat
Heat
RF Behavior - RF In The Environment

92. Absorption
Look Familiar?
Heat
RF Behavior - RF In The Environment

93. Absorption
What Else?
♦ Also called atmospheric attenuation
♦ Measured in dB
Heat
RF Behavior - RF In The Environment

94. Atmospheric
Attenuation

95. Absorption
Recall From Before
Output Power
Free Space Loss
Absorption
RF Behavior - RF In The Environment

96. RF In The Environment
Free Space Loss
Skin Effect
Absorption
Reflection

97. Reflection
What Is It?
♦ When RF waves travel through the air, some
things they encounter cause the signal to be
reflected
• Buildings
• Mountains
• Automobiles

98. Reflection
In Fact
♦ Some materials reflect the RF completely
• Metal
♦ Some reflect the RF only partially
• Wood
• Concrete
RF Behavior - RF In The Environment

99. Reflection
What Does Than Mean?
♦ Some materials absorb AND reflect RF waves
RF Behavior - RF In The Environment

100. Reflection & Absorption
Visual Depiction Heat
Incident wave
Transmitted wave
Reflected wave

101. Recap
Free space loss Due to signal spreading out
Skin effect Signal on surface of conductor
Absorption Due to the environment
Reflection Signal direction changes

102. 2. RF Behavior
Loss & Gain
Decibels
Bandwidth
RF in the Environment
Match

103. Match
Impedance
♦ Components have impedance
♦ Conductors have impedance
♦ Conductors connect components
RF Behavior - Match

104. Match
Impedance
♦ Components & conductors should have the same
impedance
• 50 ohms
♦ But they don't
• Their impedances
don't "match"
RF Behavior - Match

105. Match
Why Don't Things Match?
♦ Different standards
• 50 ohms in the RF world
• 75 ohms in the video world
♦ Impedance varies
• Over frequency
• From unit to unit
RF Behavior - Match

106. Mismatch
What Are The Consequences?
♦ The RF signal gets reflected
• The bigger the mismatch, the greater the reflection
♦ If too much signal gets reflected
• Adverse effects
RF Behavior - Match

107. Mismatch
Good match
Incident signal
Reflected signal
Poor match
Incident signal
Reflected signal
RF Behavior - Match

108. Match
How Is Match Measured?
♦ Two ways
• VSWR (Voltage Standing Wave Ratio)
• Return loss (RL)
RF Behavior - Match

109. VSWR
VSWR Meaning
1.0:1 Perfect match
1.4:1 Excellent match
2.0:1 Good match
10:1 Poor match
∞:1 Special cases
RF Behavior - Match

110. VSWR Special Cases
∞:1 (VSWR is infinite)
1) Perfect open
• Conductor/component left unattached
2) Perfect short
• Conductor/component short circuited
ALL RF ENERGY REFLECTED
RF Behavior - Match

111. Return Loss
Meaning
♦ "The loss that the return (reflected) signal
experiences"
• Big RL = small reflected signal Good
• Small RL = big reflected signal Bad
♦ Measured in dB
• Just like insertion loss
RF Behavior - Match

112. Return Loss
Good match
Incident signal
High RL
Reflected signal
Poor match
Incident signal
Low RL
Reflected signal
RF Behavior - Match

113. Return Loss vs VSWR
VSWR Return Loss
1.0:1 ∞
1.4:1 15.6 dB
2.0:1 9.5 dB
10:1 1.7 dB
∞ :1 0 dB
RF Behavior - Match

114. Mismatch
How To Deal With Mismatch
♦ If the mismatch is small
• Do nothing
♦ If the mismatch is large
• Impedance matching circuit
RF Behavior - Match

115. Impedance Matching
Impedance matching circuit
75 ohms 50 ohms
RF Behavior - Match

116. RF Behavior
The end

117. Module 1
1. The Basics
2. RF Behavior
3. Modulation
4. Noise

118. 3. Modulation
How RF Carries Information
AM FM PM QAM

119. 3. Modulation
How RF Carries Information
AM FM PM QAM

120. How RF Carries Information
Wireless Communications
♦ Transmitting information wirelessly requires
TWO different signals
1. Information signal (analog or digital)
2. RF signal (sine wave) or "carrier"

121. How RF Carries Information
Modulation
♦ Combining an information
signal and a carrier signal

122. How RF Carries Information
Modulation Result
♦ One signal - the carrier
♦ The carrier is manipulated to reflect the
imparted information
• Amplitude
• Frequency
• Phase
Modulation - How RF Carries Information

123. How RF Carries Information
Demodulation
♦ Separating the information signal
from the carrier
• The carrier is then"discarded"
Modulation - How RF Carries Information

124. How RF Carries Information
How Is It Done?
♦ Modulator: An RF component that combines an
information signal & a carrier
♦ Demodulator: An RF component that separates
an information signal from a carrier
Modulation - How RF Carries Information

125. How RF Carries Information
Where Is It Done?
Modulation - How RF Carries Information

126. How RF Carries Information
Where Is It Done?
Modem
Modulation - How RF Carries Information

127. How RF Carries Information
Where Is It Done?
Radio
Modulation - How RF Carries Information

128. 3. Modulation
How RF Carries Information
AM FM PM QAM

129. Amplitude Modulation (AM)
Definition
♦ Imparting information onto a sine wave by
varying the amplitude
Amplitude

130. Amplitude Modulation (AM)
Types
♦ AM: "Analog" amplitude modulation
• Information signal is analog
♦ BASK: Binary amplitude shift keying-
"digital" amplitude modulation
• Information signal is digital
Modulation - AM

131. AM
Example
Modulation - AM

132. BASK
Example
Modulation - AM

133. 3. Modulation
How RF Carries Information
AM FM PM QAM

134. Frequency Modulation (FM)
Definition
♦ Imparting information onto a sine wave by
varying the frequency
Frequency

135. Frequency Modulation (FM)
Types
♦ FM: "Analog" frequency modulation
• Information signal is analog
♦ FSK: Frequency shift keying-
"digital" frequency modulation
• Information signal is digital
Modulation - FM

136. FM
Example
Modulation - FM

137. FSK
Example
Modulation - FM

138. 3. Modulation
How RF Carries Information
AM FM PM QAM

139. Phase Modulation (PM)
Definition
♦ Imparting information onto a sine wave by
shifting the phase of successive sine waves
90º Phase
360º
0º 180º
270º

140. Phase Shift
What Is It?
♦ Successive sine
waves starting at a
different point on
the sine wave
• Measured with
respect to the
previous sine wave
Modulation - PM

141. 90° Phase Shift
In Action
Phase shift: 0°

142. 90° Phase Shift
In Action
Phase shift: 0°

143. 90° Phase Shift
In Action
Phase shift: 0°

144. 90° Phase Shift
In Action
Phase shift: 0°

145. 90° Phase Shift
In Action
Phase shift: 0°

146. 90° Phase Shift
In Action
Phase shift: 90°

147. Phase Modulation (PM)
Types
♦ PM is digital modulation ONLY
• Information signal is digital
♦ Many different types
• BPSK: Binary phase shift keying
• QPSK: Quadrature phase shift keying
Modulation - PM

148. Phase Shift
How Does It Represent Digital Info?
♦ "0" = 0° phase shift
♦ "1" = 180° phase shift
Phase shift: 0°
Digital bit: 0

149. Phase Shift
How Does It Represent Digital Info?
♦ "0" = 0° phase shift
♦ "1" = 180° phase shift
Phase shift: 180°
Digital bit: 1

150. BPSK
Example
Modulation - PM

151. Phase Shift
It Can Represent More Information
♦ "00" = 0° shift ♦"10" = 180° shift
♦ "01" = 90° shift ♦"11" = 270° shift
Phase shift: 0°
Digital bit: 00

152. Phase Shift
It Can Represent More Information
♦ "00" = 0° shift ♦"10" = 180° shift
♦ "01" = 90° shift ♦"11" = 270° shift
Phase shift: 90°
Digital bit: 01

153. Phase Shift
It Can Represent More Information
♦ "00" = 0° shift ♦"10" = 180° shift
♦ "01" = 90° shift ♦"11" = 270° shift
Phase shift: 180°
Digital bit: 10

154. Phase Shift
It Can Represent More Information
♦ "00" = 0° shift ♦"10" = 180° shift
♦ "01" = 90° shift ♦"11" = 270° shift
Phase shift: 270°
Digital bit: 11

155. QPSK
Example
Modulation - PM

156. QPSK
Example
Modulation - PM

157. QPSK
Example
Modulation - PM

158. QPSK
Example
Modulation - PM

159. QPSK
Example
Modulation - PM

160. 3. Modulation
How RF Carries Information
AM FM PM QAM

161. Quadrature Amplitude Modulation (QAM)
What Is It?
♦ A combination of amplitude shift keying and
phase shift keying
• For digital information signals only
♦ Several different kinds
• QAM-8
• QAM-16
• QAM-64
Modulation - QAM

162. QAM - 8
How Does It Represent Digital Info?
♦ Amplitude shift keying (BASK)
• "0" = low
• "1" = high
♦ Phase shift keying (QPSK)
• "00" = 0°
• "01" = 90°
• "10" = 180°
• "11" = 270°
Modulation - QAM

163. QAM - 8
Example
Modulation - QAM

164. QAM - 8
Example
Modulation - QAM

165. QAM - 8
Example
Modulation - QAM

166. Spectral Efficiency
Bits/Second/Hertz
♦ BPSK: 1 bps/Hz
♦ QPSK: 2 bps/Hz
♦ QAM: 3 bps/Hz

167. Recap
Modulation Analog Digital
AM “AM” BASK
FM “FM” FSK
PM N/A BPSK
QPSK
QAM N/A BASK+
QPSK

168. Modulation
The end

169. Module 1
1. The Basics
2. RF Behavior
3. Modulation
4. Noise

170. 4. Noise
What Is It?
Link Budget
Noise Effects

171. 4. Noise
What Is It?
Link Budget
Noise Effects

172. Noise
What Is It?
♦ Signal disturbance
♦ Unwanted signal(s), also called interference
Where Does It Come From?
♦ Environment
♦ Man made
Noise - What is it

173. Noise
Types
♦ AM: Unwanted changes to the amplitude
• Predominantly environment
♦ FM: Unwanted changes to the frequency
• Predominantly hardware
♦ PM: Unwanted changes to the phase
• Predominantly hardware
Noise - What is it

174. Noise
A Function Of Bandwidth & Temperature
♦ Noise density
♦ "Noise floor”
• Thermal noise
-120 dBm
Noise - What is it

175. 4. Noise
What Is It?
Link Budget
Noise Effects

176. Signal To Noise Ratio (S/N)
Definition
♦ A measure (in dB) of how much bigger the
received signal is relative to the noise floor
• AM: 40-50 dB
• FM: 20-30 dB Receiver sensitivity
• Digital: 10-20 dB
Noise - Link budget

177. Link Budget
Power out 40 dBm
Free space loss 120 dB
-80 dBm
Absorption 10 dB
-90 dBm
S/N 30 dB
Noise floor -120 dBm

178. Link Budget
Noise Spectrum Signal Spectrum

179. Shannon’s Theorem
Maximum Data Rate
♦ A function of bandwidth
♦ A function of S/N ratio
Noise - Link budget

180. 4. Noise
What Is It?
Link Budget
Noise Effects

181. Noise Effects
Analog AM
No noise
Noise - Noise Effects

182. Noise Effects
Analog AM
Noise
Noise - Noise Effects

183. Noise Effects
Digital AM
No noise
Noise - Noise Effects

184. Noise Effects
Digital AM
Noise
Noise - Noise Effects

185. Noise Effects
Phase Modulation
♦ Unwanted phase shift (e.g., 45°)
BPSK QPSK
0 0° 00 0°
45° 45°
1 180° 01 90°
♦ Shows up as increased Bit Error Rate (BER)
Noise - Noise Effects

186. Noise
The end

187. Module 1 - Introduction To RF
The end