The Design and Implementation of Solid-state Power Amplifier based on Spatial Power Combiner for X-band Vertical Pointing Radar

According to the requirement of X-band vertical pointing radar, this paper details design and implementation of a X-band solid-state power amplifier module by using an eight-way radial waveguide spatial power combiner structure. This radial waveguide spatial combiner is simulated and optimized by electromagnetic simulation software, and the simulation results show that, between 9.3GHz~9.5GHz, the insertion losses are below 0.1dB, the differences of phase between each port are within 0.5°. According to final optimization parameters, this radial waveguide spatial combiner is made of aluminum blanks, and assembled with eight power amplifiers. The measured insert loss of radial waveguide spatial combiner module is below 0.65dB, and the VSWR at each port are below 1.5:1. At 9.3GHz ~9.5 GHz, the measured gain of X-band power amplifier is greater than 35dB with ripple is less than 1dB, and the output power at P-1dB is greater than 15W. The average power combining efficiency of this SSPA module is greater than 85%.