RF Power Amplifier Design and Testing

1
RF Power Amplifier Design and Testing

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

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Presentation Overview

• Update on Project Goals
• Power Amplifier Overview
• Branch-Line Coupler
• ADS Models
• Simulation Results
• Tentative Schedule
• Questions

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Project Goals

• Original
• PA and DA from scratch
• Use Power Splitters/Combiners for increased power
• WiMAX Application (2-3 GHz)
• Output Power 1 Watt

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Project Goals

• Updated
• Tuning of Commercially Available Power Amplifier
• Power Splitter/Combiner designed from scratch
• WiFi application (2.4-2.5 GHz)
• Output Power 100mW

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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
• Return Losses

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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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Tuned ADS Model BLC
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Tuned ADS Model Results BLC
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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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Design Overview

• Power Amplifiers have been purchased-FR-4 Eval
  Board
• Additional circuitry is given in the Data Sheet
  for the Amplifier
• Fabrication will be outsourced

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RF5622 Power Amplifier

• Input/Output Matching
• DC Bias Circuits

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RF5622 Power Amplifier Layout
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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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Tasks

• Send BLC model out for Fabrication
• Simulation with Evaluation Board
• Finalize ADS Model of our PA Module
• Send Model of PA Module out for Fabrication
• Solder Components
• Test
• Present Results

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Tentative Work Schedule

• To be done before Spring Break
• All models sent for Fabrication
• Testing with Evaluation Board
• To be done after Spring Break
• Solder Components
• Test
• Present Results

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References

• 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?

• We may or may not have reasonable answers!