Power Amplifier Design Using Interactive Multi-Objective Visualization

This paper presents a method for systematic power amplifier design using a multi-objective interactive visualization method to analyze trade-offs between multiple output performance metrics. By observing load and source pull data, one can select nondominated solutions (decision variables). These have associated input and output reflection coefficients for desired output power, large signal gain, and power-added efficiency over bandwidth and drain supply voltages. A Qorvo discrete GaN device is used for validating the method, under varying frequency (2.5-5 GHz) and supply voltage (14–26 V), as well as input power. Parallel plots of nondominated designs are generated to determine the gate and drain reflection coefficients that result in the best tradeoff between output power and efficiency with a 50–Ω load. From the impedances obtained by the optimization, a circuit is designed with a measured 10-W output power and peak efficiency of 69% at 14 and 20V, validating the approach.