T型支节加载的双模双通带微带滤波器

提出了一种新颖的双模双通带滤波器。该滤波器由带有短截线的双模谐振腔和半波长U型谐振器构成。设计滤波器的中心频率为3．65GHz／8．3GHz。两个通带分别工作在S波段和X波段。源和负载的耦合是由输入和输出馈线之间的半波长U型谐振器引入。U型谐振器可以控制第二个通带的带宽。两个额外的传输零点的引入提高了滤波器的选择性和隔离度。两个通带的回波损耗均大于20dB。滤波器尺寸非常小，宽为9．2mm，长为9mm。

Dual-mode dual-band microtrip filter loaded with T-shape section

A novel microtrip dual-band filter with stub-loaded dual-mode resonant cavity and U-shape half-wavelength re- sonator is presented. The centre frequency of the designed filter is 3.65 GHz/8.3 GHz. The two passbands work at S-band and X-band respectively. The cross-coupling between the input and output lines is introduced by half-wavelength U-shape re- sonator. The bandwidth of the second passband can be controlled by U-shape resonator： The introduction of two additional transmission zeros improved the selectivity and the isolation of filters significantly. Return loss of the two passbands is more than 20 dB. The filter is very small, only 9.2 mm in width and 9 mm in length.