Ku波段GaN MMIC 高线性功率放大器设计

A Ku band GaN MMIC power amplifier working at 13.0~15.5 GHz was designed and fabricated in a 0.25 μm GaN HEMT technology. Two different output matching networks were employed and their influence on the efficiency and linearity of power amplifier were analyzed. The first one was matched to the best PAE while the second one was matched to the best linearity quantified by IM3. To get the best linearity and PAE, inter-stage matching network and input matching network were optimized. The test results indicate that the largest output power is up to 37.5 dBm and the PAE of circuit with output matching network is larger than 32% with a maximum of 36%. While linearity is increased by 1~2 dBc with PAE of 2~4 percent lower in the case of the best IM3 matching. It is suggested that to get the higher linearity, output matching network should be set between the best PAE and the best IM3.