Low-insertion-loss Gysel power combiner with high power density and high isolation

A suspended-stripline Gysel low-insertion-loss power combiner is presented in this paper. The multi-layer cavity structure reduces the circuit size and increases power density, composed of suspended strip lines and coaxial lines. The transmission-line theory is used to analyze this proposed power combiner, and the equivalent circuit model is developed to investigate the characteristics and design of the power combiner. The measured input return loss is greater than 20 dB from 7.15 to 9.35 GHz. The measured insertion loss is less than 0.36 dB, and the power-combining efficiency is greater than 92% from 7.39 to 9.19 GHz. The maximum power-combining efficiency is 98.8% at 8.1 GHz. Besides, the measured isolation is greater than 20 dB from 7 to 10 GHz. The power capacity is analyzed, and the cross-sectional power density is greater than 3.57 kW/cm(2). The measured and simulated results show reasonable agreement with each other.