陷波特性超宽带带通滤波器设计

Design of ultra-wideband bandpass filter with notched band

应用级联低通滤波器与带通滤波器的方法设计了一款高性能小型化的超宽带带通滤波器。低通滤波器由输入、输出馈线与枝节加载型多模谐振器应用零度馈电方式构成;带通滤波器由输入、输出馈线上加载短路枝节构成。超宽带滤波器的陷波特性由加载的开路枝节实现。该超宽带滤波器的仿真结果显示,其相对带宽达到143.71%,带内插入损耗S21优于-0.8 dB,回波损耗S11优于-10.76 dB。陷波频段在8.04 GHz附近,最大陷波深度达到-28.45 dB,可有效提升超宽带滤波器对卫星通信系统的抗干扰能力。

A high-performance and miniaturized ultra-wideband bandpass filter is designed by cascading low-pass filter and band-pass filter. The low-pass filter is formed by zero-feed of input/output feed lines and loaded-stub multimode resonator, and the short-circuited stub loaded at I/O feed lines to constitute a bandpass filter. The notched characteristics of the filter is achieved by open-circuit stub. The simulated results show that the fractional bandwidth is 143.71%, the minimum insertion loss of the ultra-wideband filter is about-0.8 dB and maximum return loss is-10.76 dB in passband. The notched center frequency of the UWB filter is 8.04 GHz, and the notched depth is-28.45 dB,which could avoid the interference of the satellite communication system on UWB filter effectively.