High-Selective and Compact-Size Diplexer-Integrated Filtering Power Divider Using Tri-Mode Stub-Loaded Resonators

Diplexer-integrated filtering power divider (PD) is proposed in this article. The tri-mode stub-loaded resonators, which not only resonate to generate transmission poles but also have an inherent ability to provide two extra transmission zeros (TZs), are used to form the diplexer-integrated filtering PD. For demonstration, a microstrip diplexer-integrated filtering PD with a respective central frequency of 1.17 GHz/1.485 GHz and a respective bandwidth of 140 MHz/150 MHz is designed, fabricated, and measured, which exhibits good equal power split and filtering responses of each channel and high isolation among channels. The proposed multifunctional diplexer can be a good candidate for microwave systems.