A high-isolation eight-way Power Combiner

A high-isolation eight-way power combiner is proposed in this paper. It is constructed by cascading three-stage power combiners in series. Its high isolation and low return loss characteristics are realized by the lumped isolators, side isolated network, and resistive septum. The eight-way power combiner is substantially a 17-port mode network. It consists of eight input ports, eight matching ports, and one output port. The mode network matrix cascade computation clearly reveals its working mechanism. Based on the 17-port network, an eight-way power combiner is realized with eight matching ports connected to loads. The model has been constructed and simulated in Hfss software. Simulation shows that from 8 to 10 GHz, the return loss is greater than 20 dB, the isolation is greater than 20 dB, and insertion loss is less than 0.15 dB. Its cross-section areas are approximately 0.3 λ×1.5 λ for the central frequency of 9 GHz. It is suitable for the integration of high power amplifiers.