Wideband Multi-Channel Multi-Way Power Combiner With High Frequency Selectivity

A wideband multi-channel multi-way power combiner with high frequency selectivity circuit using the center-loaded multimode step impedance resonator (SIR) is presented in this brief. The SIR stubs can generate four transmission zeros on the both sides of the passbands, which improves the frequency selectivity of the two channels. The distributed coupling technique is used to connect the two different-frequency channels without any additional matching network. The presented power combiner is designed, fabricated, and measured. The measured center frequency and relative 3-dB bandwidth of the two channels are 1.73/2.71 GHz and 43%/35%, respectively. The measured input return loss are greater than 16.4/20.8 dB, the measured output return loss is greater than 20.4/13.4 dB, and the measured insertion loss are 0.7/1.0 dB. Moreover, the measured different-frequency isolation between the two channels is greater than 26.8 dB, and the measured same -frequency isolation are greater than 23.9/29.1 dB, respectively.