A four‐way broadband filtering power divider with improved matching network for X‐band application

Abstract

AbstractThis study presents a novel design methodology of one‐to‐four filtering power divider (FPD) with a broadband response. It comprises three one‐to‐two power dividers (PDs) and a broadband bandpass filtering circuit in series. The impedance transformer of the one‐to‐two PD is designed into a dual‐T‐type symmetrical structure for improving the matching network and broadening the bandwidth, which includes a tapered transmission line, two cascaded microstrip lines with the same characteristic impedance, as well as a stepped‐impedance open stub. The bandpass filtering circuit is formed by three coupled quarter‐wavelength microstrip lines in parallel, where the intermediate subresonator is grounded via a hole instead of half wavelength line for pursuing a wider bandpass characteristic. The proposed FPD is fabricated and measured. The good performance is achieved with the return loss of >13.8 dB for input/output ports as well as minimum insertion loss of <0.21 dB (over the −6 dB splitting ratio) from 7.3 to 13 GHz.