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?