Filtering power divider with improved isolation bandwidth using frequency‐varying network

Abstract

This letter presents a method to design filtering power divider (FPD) with expanded isolation bandwidth (IBW). In the proposed FPDs, two novel frequency-varying isolation networks (INWs) derived from the network matrix theory are used to improve the IBW. At the same time, coupled lines are applied to generate filtering properties. For verification, three FPDs operating at 2.4 GHz are fabricated. Measured results indicate that the two INWs achieve 26.6% and 31.6% 20 dB IBW, respectively. Compared with traditional FPD, IBW has been improved by 56.5% and 86% within the passband.