全微带结构三阶全范数横向滤波器设计

全微带结构三阶全范数横向滤波器设计

内容简介：滤波器尺寸直接影响整个前端系统的集成度，滤波器小型化一直是研究热点。设计了一种紧凑的全微带结构的三阶全范数微波滤波器，该滤波器基于一短路枝节加载双模谐振器和一终端短路的半波长偶模谐振器，从而构成了全微带结构的三阶横向滤波器。相比传统纵向滤波器，微带结构的三阶全范数横向滤波器具有结构紧凑、选择性高和便于加工制造等优点。由于引入了源与负载直接耦合，该滤波器通带两侧具有3个传输零点，显著提高了滤波器的通带选择性以及消除了无用的高次谐波信号。设计的滤波器中心频率为1??5 GHz，绝对带宽为80 MHz，回波损耗约为22 dB。实测结果和仿真结果基本吻合。滤波器尺寸约为0??14λg ×0??076λg ，其中λg 为中心频率对应的波导波长。

Abstract：The size of filters impacts directly the whole front-end system integration,and the miniaturization of filters is always research hot spot.This paper proposes a compact three-order full canonical transversal microstrip bandpass filter.The microstrip filter is based on a short stub loaded dual-mode resonator (SSLDR) and a short-ended half-wavelength resonator (SEHR).Different from the conventional microwave filter,the three-order full canonical transversal microstrip filter presents miniaturization,high selectivity and simple fabrication.By utilizing the resonance properties of the transversal filter and the introduced source-load coupling (S-L coupling), the filter is designed with three transmission zeros at both sides of passband.The selectivity of passband is improved and the unwanted signal beyond the passband is rejected due to the transmission zeros.A 1?? 5 GHzthree-order transversal BPF is designed,which presents 80 MHz absolute bandwidth and an in-band return loss of 22 dB.The measured results match well with the simulations,and size of the proposed filter is less than 0.14λg ×0.076λg ,where λg is the guided wavelength at the center frequency.

作者：吴景宇, 位朝垒, 李晶,

关键词：微带, 横向滤波器, 传输零, 源与负载耦合