Design of 1.9-2.6 GHz Filtering Power Amplifier Based on Impedance and S-Parameter Optimization

To minimize mismatch and additional insertion loss between the power amplifier and the filter, a filtering power amplifier (FPA) using a terminated coupled line structure (TCLS) is designed. The output matching network is optimized using an algorithm based on impedance and S-parameter to improve the output power and efficiency. The TCLS matches the fundamental impedance and incorporates a low-pass filter to suppress high-order harmonics. A 1.9-2.6 GHz broadband high-efficiency FPA was designed and implemented. Measurement results indicate that the saturation efficiency ranges from $\mathbf{6 0 \%}$ to 68%, and the saturated output power is between 39.3 dBm and 42.5 dBm over the whole operating frequency band.