基于双模谐振器的W波段波导带通滤波器

W-Band Waveguide Bandpass Filter Using Dual-Mode Resonances

带通滤波器为现代毫米波系统中进行频率选择的重要器件,而波导滤波器因其低损耗、大功率容量、易加工等优点成为首选。为满足系统的小型化要求,设计并制作了一款基于双模谐振器且具有准椭圆函数响应的W波段波导带通滤波器。该波导带通滤波器结构简单紧凑,由两个双模方形脊谐振腔组成,可获得2个传输零点及四阶准椭圆函数响应,结构简单紧凑。滤波器样品选取紫铜材质,采用CNC技术加工制作。经矢量网络分析仪测试,该滤波器通带内最小插损0.5 dB,3 dB波束带宽为4.35%（92.2-96.3 GHz）,回波损耗优于20 dB,通带外存在两个非对称零点。在全W波段的测试结果与仿真数据高度吻合。

The bandpass filter is one of the essential components for frequency selecting in modem millimeter wave system. Waveguide bandpass filters with advantages of low loss, high power handling and easy fabrication are preferred. In this letter, a W-band waveguide bandpass filter with quasi-elliptical response using dual-mode resonances is developed. This bandpass filter features a compact and simple construction, in which two dual-mode square ridge cavity resonators are used to generate two transmission zeros and support the required fourth-order response. The filter fabricated within the red copper block by CNC-milling process exhibit a low insertion loss of about O. 5 dB, a 3 dB fractional bandwidth of 4.35 % from 92.2 GHz to 96.3 GHz, the return loss is mainly lower than 20 dB, and two evident transmission zeros in the out-of-band. The measured results are in good agreement with the simulated ones in the full W-band.