RF Power Amplifier Design and Testing By Jonathan
RF Power Amplifier Design and Testing By: Jonathan Lipski and Brandon Larison Advisor: Dr. Shastry
Why is this important? n “Wherever there are wireless communications, there are transmitters, and wherever there are transmitters, there are RF power amplifiers” -Steve Cripps
Presentation Overview n n n n Project Goals Power Amplifier Overview Branch-Line Coupler ADS Models Simulation Results Final Results Concluding Remarks Questions
Project Goals • Building of Power Amplifier Module using: Commercially Available Power Amplifier Chip n Power Splitter/Combiner designed from scratch n • Wi. Fi application (2. 4 -2. 5 GHz) • Output Power = 100 m. W
RFMD RF 5622 Power Amplifier n n Input/Output Matching DC Bias Circuits
RF 5622 Power Amplifier Layout
Power Amplifier Module
Power Splitters/Combiners n Why use them? • Same gain • Higher power n Branch Line vs. Wilkinson • Extra Resistor Needed
Branch Line Coupler Model
Branch Line Coupler Theory
Calculations n Widths & Lengths • MSTRIP. exe • Center Frequency and Characteristic Impedance • VT-42 Data Sheet (Micro Circuits) Height of substrate n Dielectric Constant n
First Iteration ADS Model: BLC
First Iteration ADS Results: BLC
Port Performance relative to Port 1
Return Losses
Phase Difference
Isolation Losses
Tuned ADS Model: BLC
Tuned ADS Model Results: BLC
Port Performance relative to Port 1
Return Losses
Phase Difference
Isolation Losses
ADS Layout: BLC
First Iteration ADS Model: PA Module
First Iteration ADS Results: PA Module
Port Performance relative to Port 1
Return Losses
Phase Difference
Isolation Losses
Tuned ADS Model: PA Module
Tuned ADS Results: PA Module
Port Performance relative to Port 1
Return Losses
Phase Difference
Isolation Losses
ADS Layout: PA Module
ADS Layout: PA Chip
PA Module
Testing Procedure n Wi. MAX • Instrumentation cannot handle the power levels we’ll be using n Wi. Fi • Requires much less power
Testing Procedure n Network Analyzer • Measures Return Losses, VSWR, S-Parameters n Spectrum Analyzer • Measures Output Power
Final Results n n n Board currently needs to be soldered Testing will occur after Results and Simulation comparisons will be documented in final report
Concluding Remarks Aspects we learned: • Power Amplifier Theory • Power Divider/Combiner Design • Microstrip Line Fabrication
Concluding Remarks Recommendations for Future: • Choose the design first, application second • Estimate fabrication time, then double it
References n n n 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. <http: //www. rfpoweramplifier. org/high_power_rf_amplifier. html>. "RF Power Amplifier. " Wikipedia, the Free Encyclopedia. Web. 25 Sept. 2011. <http: //en. wikipedia. org/wiki/RF_power_amplifier>. RFMD, comp. RF 5622 Data Sheet. Greensboro, NC: RFMD, 2006. Print.
Questions?
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