基于零度馈电的共面波导双通带滤波器

Coplanar waveguide dual-passband filter based on zero-degree feed

为了满足工作在多频段的通信系统的需求,提出了一种零度馈电结构的共面波导双通带滤波器。利用共面波导不连续性结构生成第一通带,再采用零度馈电结构激励开路枝节生成第二通带。滤波器第一通带中心频率为1.2 GHz,带宽为300 MHz,带内插入损耗优于0.15 dB。第二通带中心频率为2.45 GHz,带宽为250 MHz,带内插入损耗优于0.43 dB。滤波器带外有四个传输零点,提高了通带隔离度、选择性和阻带抑制性能。对滤波器进行了加工与测试,实测结果与仿真结果基本一致,验证了设计的有效性。滤波器结构简单,尺寸较小,仅为0.16λg×0.16λg,对于工作在北斗导航B2/B3频段和ISM频段的通信系统有一定的应用价值。

In order to meet the needs of the multi-band application of the communication systems,a coplanar waveguide dual-passband filter with zero-degree feed structure was proposed.The first passband was generated by the coplanar waveguide discontinuity structure,and then the second passband was generated by the excitation of the open-stubs with the zero-degree feed structure.The center frequency of the first passband of the filter is 1.2 GHz with the bandwidth of 300 MHz,and in-band insertion loss is better than 0.15 dB.The center frequency of the second passband is 2.45 GHz with the bandwidth of 250 MHz,and in-band insertion loss is better than 0.43 dB.There are four transmission zeros outside the band of the filter,as a result,the passband isolation,selectivity and stopband suppression performance are improved.The filter was fabricated and tested,and the measured results were basically consistent with the simulated results,which verified the effectiveness of the design.The filter has simple structure and small size,which is only 0.16λg×0.16λg,and it has potentials for the communication system working in B2/B3 band of Beidou navigation and ISM band.