Signal Generation and Conditioning

1

• Signal Generation and Conditioning

2
Passive Components

• Complex
• Amplitude and phase
• Impedance
• Resistor Z R
• Inductor Z j?L
• Short at DC
• Capacitor Z 1/( j?C)
• Short at high frequency
• Series ZZ1Z2
• Parallel 1/Z1/ Z1 1/Z2

3
In Series

• ZZ1Z2
• Voltage Divider
• Maximize Power Delivered to Load
• Impedance Matching

4
LC Resonator

• LC in parallel
• 1/Z1/ Z1 1/Z2
• Frequency Response
• Resonance frequency
• Z at fR
• Effect of R
• Bandwidth
• Q
• What about LC in series?

5
Making Inductors

• Cylindrical inductor, N turns of wire The ideal
  inductance is given by
• when d is much greater than the diameter
• http//hibp.ecse.rpi.edu/connor/education/EIexp-p
  roj-lect/exp03.ppt
• http//www.ee.surrey.ac.uk/Workshop/advice/coils/

6
Circuit Practice

• At high frequencies no circuit elements are
  simple.
• Capacitor has series stray inductance, parallel
  leakage resistance.
• The junction capacitances of transistors must be
  considered.
• A wire has stray inductance and capacitance
  causing unexpected feedback.
• Connecting wire is a transmission line.
• Ground plane and isolation are extremely
  important.
• Use decoupling capacitors and negative feedback.

7
Amplifiers

• Class A CE Amplifier
• Tuned
• Inductor (choke) or
• transformer
• Configuration
• Gain vs ZC
• A(f)
• Linear

8
Amplifiers

• Other Configurations
• Common base amplifier (http//www.eee.bham.ac.uk/c
  ollinst/walkthroughs/cb-amp/)
• Class B amplifier
• Class C amplifier
• No base bias
• No dc current
• High efficiency
• Nonlinear
• Harmonic frequency amplification

9
Class C Amplifier

• Bode Plot
• Waveform
• fR

10
Class C Amplifier

• Waveform
• fR/2
• http//hem.passagen.se/communication/clc.html
• Feedback Control
• Neutralization cancel unwanted feedback

11
Power Amplifier - Efficiency

• DC Power
• Signal Power
• Efficiency
• Amplifiers
• Class A resistor lt25
• Class A inductor lt50
• Class B lt78.5
• Class C lt100
• Class D,
• http//ocw.mit.edu/NR/rdonlyres/Electrical-Enginee
  ring-and-Computer-Science/6-776Spring-2005/3239E36
  0-13B6-4830-A9C6-8BC2E574E770/0/lec18.pdf

12
Amplifier Design

• Impedance Matching
• Gain and Frequency Dependence
• Bandwidth
• Uniformity
• Distortion
• Crosstalk
• Noise
• Device
• Circuit
• Low Noise Amplifier Designs
• http//ocw.mit.edu/NR/rdonlyres/Electrical-Enginee
  ring-and-Computer-Science/6-976High-Speed-Communic
  ation-Circuits-and-SystemsSpring2003/0A7661A1-C163
  -478D-AFFE-DC6C233216EC/0/lec9.pdf
• http//www-smirc.stanford.edu/papers/aacd98p-tom.p
  df

13
RF Amplifiers

• RF Connectors
• Power
• Control
• Surface Mount
• Transmission Line
• Shield

14
Oscillator

• Positive Feedback With Gain
• Amplifier
• Operational amplifier
• Bipolar junction transistor amplifier
• FET
• GaAs HEMT
• In phase feedback
• 0-degree for op amp with non-inverting input
• 180-degree for CE BJT

15
RC Feedback

• Feedback Loop
• Bode Plot
• Amplitude
• Phase

16
Wien Bridge Oscillator

• Circuit Diagram
• Characteristics
• Sine wave
• Low Q
• http//webapps.calvin.edu/pribeiro/courses/engr33
  2/Handouts/Wein20Bridge20Oscillators20Presentat
  ion-Darren.ppt

17
LC Feedback

• Feedback Loop
• Capacitor divider
• Inductor tap
• L1-C2 Divider
• Resonator Characteristics
• Capacitors in series resonate with inductor
• 180-degree phase change at resonance
• Feedback factor
• Q

18
LC Oscillators

• Hartley Oscillator
• (http//www.geocities.com/neveyaakov/electro_scie
  nce/hartley.html)
• Colpitts Oscillator
• Reference (http//www.du.edu/etuttle/electron/ele
  ct16.htm)

19
Colpitts Oscillators

• Common Source
• Common Base
• ftp//ftp.ni.com/pub/devzone/tut/3_lab_fm_colpitt
  s.doc

20
RD Topics on Oscillators

• Phase Noise
• http//ieeexplore.ieee.org/iel5/4/17940/00826814.p
  df?tparnumber826814isnumber17940
• GHz Voltage Controlled Oscillator IC
• Chaos

21
Tunability

• Varactor
• Voltage dependent capacitance

22
Tunable Oscillators

• Clapp Oscillator Using Varactor
• VCO
• XR-2207
• LM556
• Function Generators
• XR-2206 Monolithic function generator

23
Crystal Oscillator
http//www.npc.co.jp/ja/general/icmt2002_npc.pdf
24
Crystal Oscillator

• High Q
• Piezoelectric Effect
• Crystal Cuts
• Working Range
• 50kHz-40MHz
• Temperature Coefficient
• 10 Hz/MHz/C
• ?f k f0 ?T (C)
• http//www.txc.com.tw/en/d_support/01.html

25
Analysis

• Equivalent Circuit
• Equation
• Zero R
• Serial
• Z 0
• Parallel
• Z h
• Non Zero R?

26
Crystal Oscillator

• Typical Values

27
Resonance

• Characteristics
• Large, low loss inductor
• Cp (pF) gtgt Cs (fF)
• High Q circuit
• fs very close to fp
• Operating Frequency
• fs lt f lt fp

28
Crystal Circuits

• Oscillator Circuits
• Logic Gate
• L, Cs
• Cp
• C1, C2
• CB
• L, Cs
• fs
• http//www.northcountryradio.com/PDFs/column007.pd
  f
• http//www.caliberelectronics.com/oscillator-desig
  n.htm
• Crystal Filter
• http//www.aade.com/filter32/dishal.htm

29
Mixers

• Combinations of Input Frequencies
• Nonlinear Devices
• Diode, Transistor, FET
• Intrinsic Response
• New Frequencies
• Effects of Nonlinearity
• New frequency generation
• In band interference

30
Balanced Mixer

• Characteristics
• Input
• Output Frequencies

31
Gilbert Cell

• Differential Amplifier Implementation
• (http//members.tripod.com/michaelgellis/gilbert.h
  tml)
• MOS Implementation
• (http//eesof.tm.agilent.com/adsdemo/seminar4/abs
  tract.html)

32
Phase Lock Loop

• Historical Review
• (http//www.uoguelph.ca/antoon/gadgets/pll/pll.ht
  ml)
• Block Diagram
• Phase Detector
• LPF, Amplifier
• VCO
• Phase-Locked Loop
• XR-215A
• Characteristics
• www.nxp.com/acrobat_download/applicationnotes/
• AN177.pdf
• Free-Running Frequency
• Capture Range
• Lock Range
• (drift beyond capture)

33
PLL

• Waveform
• Reference
• Local oscillator
• Loop filter?
• Digital PLL
• Incremental counter
• Clock generator
• http//www.erg.abdn.ac.uk/users/gorry/course/phy-p
  ages/dpll.html

34
PLL

• PLL Laboratory
• http//ece-www.colorado.edu/ecen4618/lab4.pdf
• http//inst.eecs.berkeley.edu/ee128/fa05/labs/lab
  _3/lab3.pdf
• PLL Characterization
• http//www.analog.com/library/analogDialogue/archi
  ves/33-05/phase_locked/index.html
• http//www.tektronix.com/Measurement/App_Notes/61_
  18193/eng/61W_18193_0.pdf

35
Applications of PLL

• Carrier or Clock Synchronization
• FM or FSK Detection
• Improved S/N after detection
• Frequency Synthesis

36
Frequency Synthesis

• Frequency Synthesizer
• Divider (counter)
• Mixer
• Multiplier
• PLL with divide by N
• Pre-scaler
• Comb generator
• Examples
• 14.318 MHz and
• TI CDC960 IC
• TSA6057 radio-tuning
• PLL frequency synthesizer

37
Chapter Review

• LC
• Tuned amplifier
• Class C amplifier
• Feedback
• Oscillators
• Q, crystal
• Tunable VCO
• Mixer
• Phase lock loop
• Frequency synthesis