Cross-band microstrip diplexer design

Abstract

A large span ultra-broadband microstrip planar structured diplexer are presented. Firstly, this paper describes the general steps for designing filters based on the synthesis of N+2 coupling matrices, based on microstrip lines. Secondly, this paper implements a dual-way frequency combing of C and X band satellite downlink signal based on a cross-finger filter structure and a microstrip T-junction. Finally, the diplexer was tested for practical processing. The diplexer operates in the frequency range of 3.7GHz-4.2GHz and 7.25GHz-7.75GHz, with in-band insertion loss better than 1.6dB and 2.6dB respectively, return loss better than 15.6dB and 15dB respectively, and passband isolation greater than 60dB. The test results are consistent with the simulation results and meet the design specifications

A Compact Negative Group Delay Microstrip Diplexer with Low Losses for 5G Applications

“…Several different microstrip configurations are presented to create diplexers for wireless RF applications. A cross-band microstrip diplexer is presented in (Duan, et al, 2023). The dual-mode squared shape BPFs are used to obtain a microstrip diplexer in (Alnagar, et al, 2022).…”

“…The dual-mode squared shape BPFs are used to obtain a microstrip diplexer in (Alnagar, et al, 2022). The common problems of the proposed diplexers in (Al-Majdi and Mezaal, 2023;Deng, Xu and Zheng, 2023;Chaudhary, Roshani and Shabani, 2023;Duan, et al, 2023;Alnagar, et al, 2022) are their high insertion losses and large dimensions. Based on a new resonator, a compact diplexer is proposed in (Yahya, Rezaei and Nouri, 2021) which works at 3 GHz and 1.4 GHz for S-band and L-band wireless applications.…”