RF Power Amplifier Design and Testing

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RF Power Amplifier Design and Testing

• By Jonathan Lipski and Brandon Larison
• Advisor Dr. Shastry

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Why is this important?

• Wherever there are wireless communications,
  there are transmitters, and wherever there are
  transmitters, there are RF power amplifiers
  -Steve Cripps

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Presentation Overview

• Project Goals
• Power Amplifier Overview
• Branch-Line Coupler
• ADS Models
• Simulation Results
• Final Results
• Concluding Remarks
• Questions

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Project Goals

• Building of Power Amplifier Module using
• Commercially Available Power Amplifier Chip
• Power Splitter/Combiner designed from scratch
• WiFi application (2.4-2.5 GHz)
• Output Power 100mW

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RFMD RF5622 Power Amplifier

• Input/Output Matching
• DC Bias Circuits

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RF5622 Power Amplifier Layout
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Power Amplifier Module
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Power Splitters/Combiners

• Why use them?
• Same gain
• Higher power
• Branch Line vs. Wilkinson
• Extra Resistor Needed

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Branch Line Coupler Model
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Branch Line Coupler Theory
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Calculations

• Widths Lengths
• MSTRIP.exe
• Center Frequency and Characteristic Impedance
• VT-42 Data Sheet (Micro Circuits)
• Height of substrate
• Dielectric Constant

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First Iteration ADS Model BLC
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First Iteration ADS Results BLC
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Port Performance relative to Port 1
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Return Losses
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Phase Difference
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Isolation Losses
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Tuned ADS Model BLC
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Tuned ADS Model Results BLC
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Port Performance relative to Port 1
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Return Losses
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Phase Difference
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Isolation Losses
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ADS Layout BLC
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First Iteration ADS Model PA Module
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First Iteration ADS Results PA Module
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Port Performance relative to Port 1
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Return Losses
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Phase Difference
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Isolation Losses
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Tuned ADS Model PA Module
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Tuned ADS Results PA Module
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Port Performance relative to Port 1
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Return Losses
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Phase Difference
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Isolation Losses
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ADS Layout PA Module
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ADS Layout PA Chip
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PA Module
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Testing Procedure

• WiMAX
• Instrumentation cannot handle the power levels
  well be using
• WiFi
• Requires much less power

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Testing Procedure

• Network Analyzer
• Measures Return Losses, VSWR,
• S-Parameters
• Spectrum Analyzer
• Measures Output Power

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Final Results

• Board currently needs to be soldered
• Testing will occur after
• Results and Simulation comparisons will be
  documented in final report

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Concluding Remarks

• Aspects we learned
• Power Amplifier Theory
• Power Divider/Combiner Design
• Microstrip Line Fabrication

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Concluding Remarks

• Recommendations for Future
• Choose the design first, application second
• Estimate fabrication time, then double it

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References

• Cripps, Steve C. RF Power Amplifiers for Wireless
  Communications. Boston Artech House, 1999.
  Print.
• Gonzalez, Guillermo. "4.7-4.8." Microwave
  Transistor Amplifiers Analysis and Design. Upper
  Saddle River, NJ Prentice Hall, 1997. 352-74.
  Print.
• Grebennikov, Andrei. "Power Amplifier Design
  Fundamentals More Notes from the Pages of
  History." High Frequency Electronics May 2010
  18-30.
• "High Power RF Amplifier." RF Power Amplifier
  Powerful Amplification. Web. 25 Sept. 2011.
  lthttp//www.rfpoweramplifier.org/high_power_rf_amp
  lifier.htmlgt.
• "RF Power Amplifier." Wikipedia, the Free
  Encyclopedia. Web. 25 Sept. 2011.
  lthttp//en.wikipedia.org/wiki/RF_power_amplifiergt.
  
• RFMD, comp. RF5622 Data Sheet. Greensboro, NC
  RFMD, 2006. Print.

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Questions?