一种三频带微带带通滤波器的设计

Design of Microstrip Tri-Band Bandpass Filter

为了满足射频前端系统对滤波器的小型化、多频带、高集成度等性能的需求,设计并制作了一种三频带微带带通滤波器,它是由多个弯折型谐振器串联而成,可在DC～4.5GHz的工作频段内实现三频带带通滤波的功能,整体结构尺寸为40mm×15mm.利用有限元仿真软件HFSS建立三维结构模型,通过参数扫描获得带通滤波器最佳性能指标,并利用矢量网络分析仪进行测试.测试结果表明,该滤波器的三个中心频率分别为2.23,2.83,4.05GHz,插入损耗为0.91dB@4.05GHz,带外抑制为45.64dB@1.18GHz.该微带带通滤波器性能良好,测试结果与仿真结果基本一致.

A tri-band microstrip bandpass filter was designed and fabricated to satisfy the performance demand of radio frequency front-end system for the miniaturization,multi-band and high integration.It was composed of multiple bending resonators in series.The function of tri-band bandpass filter could be realized in the working frequency band of DC^4.5 GHz.The bandpass filter had a small size of 40 mm×15 mm.The three-dimensional structure model was established by using HFSS of the finite element simulation software,and the optimal performance of the bandpass filter was obtained by parameter scanning,and the vector network analyzer was used to test.The test results show that the three central frequencies of the filter are 2.23 GHz,2.83 GHz and 4.05 GHz.The insertion loss is 0.91 dB at 4.05GHz and the out-of-side rejection is 45.64 dB at 1.05 GHz.The performance of the microstrip bandpass filter is good,and the test results are in good agreement with the simulation results.