Wideband three-way power divider with bandpass filtering response using unequal-width three-coupled line

Abstract

In the paper, a wideband three-way power divider (PD) with bandpass filtering response is proposed. It consists of short-circuited-stub (SCSs) loaded unequal PD, unequal-width three-coupled lines (TCLs) and isolation resistors. By using the TCLs, as well as inserting the SCSs to the connections of the PD and the TCLs, wideband bandpass filtering response with high frequency selectivity is realized. Double even-odd mode decomposition technique is adopted for analyzing the PD with asymmetric structure, and design procedures are provided for guidance. For demonstration, a prototype operating at 1.5 GHz is designed and fabricated. Measurement results coincide well with the simulated results which show that the fractional bandwidth (FBW) of more than 80% is achieved with less than 0.8 dB insertion loss and larger than 15 dB isolation. In the bandwidth, the return losses are better than 14 dB and 18 dB for the input and output ports, respectively.