A C-Band High-Efficiency Power Amplifier MMIC With Second-Harmonic Control in 0.25 μm GaN HEMT Technology

This letter presents a
$C$
-band high-efficiency fully integrated high-power amplifier (HPA) monolithic microwave integrated circuit (MMIC) in 0.25
$\mu \text{m}$
gallium nitride (GaN) high electron mobility transistor (HEMT) technology. The proposed GaN HPA MMIC consists of two amplifying stages, and its output stage includes eight transistors in parallel. In order to realize the high efficiency, a low-loss harmonic control network (HCN) using a parallel
LC
resonate block is applied to obtain the optimum load impedance to each transistor employed in the output stage of the HPA at both
$f_{0}$
and
$2f_{0}$
. Thus, the designed GaN HPA can operate in pulse conditions of 100
$\mu \text{s}$
pulsewidth and 10% of duty cycle over the frequency from 5.6 to 6.3 GHz. The proposed high-efficiency GaN HPA MMIC provides an average output power of 45.0–45.5 dBm (31.6–35.5 W) with a power-added efficiency (PAE) of 59%–61.8%, and a gain of 26–28.5 dB under a drain voltage of 28 V. The area of the proposed GaN HPA MMIC is 4.2 mm
$\times $
4 mm including pads.