Multifunctional Quad-Channel Diplexer-Integrated Single-Pole Double-Throw Switch With Three Operating Modes

This paper introduces a novel multifunctional quad-channel diplexer-integrated single-pole double-throw (SPDT) switch with three switchable operating modes. In Modes 1 and 2, the switch serves as a dual-band SPDT bandpass filter for distinct frequency bands and is compatible with time division duplexing (TDD) systems. In Mode 3, it serves as a quad-channel switchable diplexer suitable for both TDD and frequency division duplexing systems. The quad-channel diplexer-integrated SPDT switch is designed and implemented using microstrip technology, and its functionalities in the three modes are demonstrated. Experimental results revealed that, in comparison with state-of-the-art diplexers, the proposed multifunctional diplexer has greater advantages such as compact size, versatility, multimode switching, multichannel support, and high performance.