一种基于模式匹配法的新型波导双工器设计

Design of a New Waveguide Duplexer Based on Mode Matching Method

为进一步提高频带间隔离度,获得陡峭的抑制边带同时不增加体积,文中设计了一款新型的S频段波导双工器。在传统膜片式波导滤波器的基础上,低频滤波器提出了一种新型的波导CT型感性交叉耦合结构,高频滤波器引入非谐振腔结构,工作频段为2.025~2.12 GHz&2.2~2.3 GHz。根据其结构的不连续性,采用模式匹配法进行快速分析设计。该双工器在通带的高、低频带外均产生了传输零点,在2.2~2.3 GHz与2.025~2.12 GHz频段内,隔离度分别大于60 dB与90 dB,回波损耗大于20 dB。与同等性能的传统双工器相比,该双工器尺寸小、设计简洁,可在电子工程中广泛应用。

In order to further achieve the requirement of high isolation between frequency bands without increasing the size of the duplexer, this paper proposes a new type of waveguide duplexer. Based on the traditional diaphragm waveguide filter, the low-frequency filter of this duplexer uses a new waveguide CT-type inductive cross-coupling structure, and the high frequency filter introduces a non-resonant cavity structure. An S-band duplexer with a working frequency band of 2.025-2.12 GHz & 2.2-2.3 GHz is designed. According to the discontinuity of its structure, the mode matching method is used to quickly analyze and design. The duplexer has transmission zeros outside the high and low frequency bands of the passband. In the 2.2-2.3 GHz and 2.025-2.12 GHz bands, the isolation is greater than 60 dB and 90 dB, and the return loss is greater than 20 dB. Compared with the traditional duplexer with the same performance, the duplexer has a small size and can be easily designed and widely used in engineering.