A Novel Triplexer Based on SISL Platform

In this paper, a novel triplexer using the substrate-integrated suspended line technology is proposed. Two matching circuits are designed to connect the three filter channels for the triplexer construction. The used bandpass filters are composed of a low-pass filter and a high-pass filter, and they have advantages of high controllability and low insertion loss. For the proposed triplexer, two adjacent filter channels compose a duplexer. Based on the design consideration, the triplexer can be extended to a multiplexer. The proposed design is further improved by using a patterned suspended substrate for loss reduction. The triplexer achieves good isolations among the three ports and low insertion losses of 1.4/1.3/0.8 dB for the three channels of 0.8, 2.5, and 5.8 GHz, respectively.