Balanced quad-band diplexer with wide common-mode suppression and high differential-mode isolation

Ching-Her Lee, Chung I.Gavin Hsu, Shang Xing Wu, Pi Hung Wen

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A balanced quad-band diplexer is proposed with wide common-mode (CM) suppression and high differentialmode (DM) isolation in this study. The six-port balanced diplexer was formed by combining two dual-band bandpass filters operating at 1.92/5.25 and 2.45/5.8 GHz through two stepped-impedance resonator (SIR) inserted T-junctions. By carefully designing the section length of the T-junction and the SIR length from its open-end to the joint-point with the T-junction, high isolation between diplexer channels can be attained. A prototype of the proposed balanced quad-band diplexer was implemented and measured with a DM isolation of higher than 51.8 dB and a CM suppression of larger than 47.9 dB in the four DM passbands. Good agreement was observed between the simulated and the measured results.

Original languageEnglish
Pages (from-to)599-603
Number of pages5
JournalIET Microwaves, Antennas and Propagation
Issue number6
Publication statusPublished - 2016 Apr 24


All Science Journal Classification (ASJC) codes

  • Electrical and Electronic Engineering

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