Design of a C-Band High Efficiency Power Amplifier With Compact Harmonic Control Network

In this letter, the design of a
$C$
-band high-efficiency power amplifier (PA) with a compact harmonic control network (HCN) is presented. Based on the device model, the optimal fundamental and second harmonic load impedance was obtained by load-pull simulation. Then a simply fundamental matching network (FMN) is realized using the simplified real frequency technique (SRFT). To improve efficiency, a compact HCN based on a predesigned FMN is proposed. Besides, the microstrip radial stub (MRS) is used instead of the microstrip open-circuited stub to reduce the loss. A high-efficiency PA working across 6.1–7.2 GHz is simulated and fabricated. Experimental results show that the fabricated PA delivers a saturated output power of 38.2–39.3 dBm with a drain efficiency (DE) of 43%–63.4% in the interested band.