宽频带低损耗的五模腔体滤波器

Wideband and low-loss cavity filter using penta-mode resonator

为满足通信系统对于高通信容量和高传输效率的需求,提出了一种低损耗宽频带腔体滤波器的设计方案。本设计采用金属矩形腔体作为谐振器,通过探针馈电和微扰金属柱同步激励单个谐振腔内五个谐振模式。同时改变馈电探针和金属柱的尺寸,可进行多模式谐振频率与传输零点的调控,实现宽频带和高选择性的滤波通道,且高品质因数的矩形腔体保证了通带内的低损耗。基于HFSS的仿真优化,进行了实物加工和测量。实测结果表明:该滤波器在中心频率11.2 GHz处实现了36%的相对带宽,通带内平均损耗0.25 dB;靠近通带两侧的多个传输零点提高了通带选择性。本文提出的五模腔体滤波器电路,具有带宽宽、损耗低和通带选择性好的优势,适用于高性能的卫星和雷达通信服务。

In order to meet the demand of high communication capacity and high transmission efficiency in communication system,a construction of wideband and low-loss cavity filter is proposed.In this design,metal rectangular cavity is employed as the resonator,and five modes of this resonator are excited simultaneously by the feeding probe and perturbed metal posts.When adjusting the dimensions of the feeding probe and perturbed metal posts,the resonant frequencies of the multiple modes and transmission zeroes could be controlled.Accordingly,a wideband filtering response with high passband selectivity is formed.In the meanwhile,the high quality factor of the cavity contributes to the low insertion loss in the passband.After simulation and optimization in HFSS,the proposed filter is manufactured and measured.As the measured results presented,this design is centered at 11.2 GHz with the fractional bandwidth of 36%,the insertion loss is 0.25 dB,multiple transmission zeroes are close to the center frequency to enhance the passband selectively.The proposed penta-mode cavity filter possesses wideband,low loss and high passband selectivity,which is applicable to satellite and radar communication services.