This paper presents an 8.8-9.8 GHz hybrid power amplifier (PA) designed with GaN HEMT bare die transistors. Generally, hybrid X-band high power amplifier (HPA) suffers from relatively low bandwidth. However, this paper introduces wideband high gain power amplifier, by using low loss Wilkinson combiner/divider, a modified form of taper-based divider, and wideband matching structures. The optimum values of all elements are determined by using Random and Gradient algorithms. The microstrip matching structures are realized on Rogers4003 and RT/druid5880 substrates. Large-signal simulation results show peak efficiency of 40%, an output power of 100 W and power gain of 50 dB at 9.5GHz. The input and output return losses are respectively less than -12 dB and -10 dB.

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