140GHz空腔滤波器设计及加工工艺研究

设计并实现了一种采用进口电火花技术加工的D波段电感膜片耦合的矩形波导空腔滤波器。采用等效电路法设计了一个140GHz矩形空腔带通滤波器。采用有限元仿真软件HFSS分析了腔体个数对滤波器主要性能的影响，最终成功设计了一个性能优良的四阶空腔滤波器，中心频率（140±3）GHz，带内插入损耗S21在-3dB以内，回波损耗S11在-20dB以下。采用电火花微加工技术成功加工出了四阶滤波器的主体部分，相应完成了结构键合等关键工艺，首次制作了基于电火花技术的D波段矩形波导空腔滤波器。测试结果为中心频率（138.5±3）GHz，带内插入损耗最好达到了-4.4dB。结果表明滤波器在140GHz具有带通特性和滤波功能，尽管与理论上的-3dB有差异，但考虑到加工误差、夹具损耗等情况下，样品主要技术指标与设计值较为一致。

The design of cavity filter at 140GHz and study on processing technology

The paper designed and achieved a rectangular waveguide cavity filter of D band with inductor diaphragm coupling by adopting electric spark micro-machining technology. Using the equivalent circuit method designed a rectangular cavity filter at 140GHz. The influence of cavity number on the main performance of the filter was analyzed. A four order cavity filter with excellent performance was designed successfully, The center frequency is (140±3)GHz, the insertion loss is within -3dB, the return loss is below -20dB. The prototypes were fabricated using electric spark micro-machining technology, the bonding technique was employed for the fabrication of filter. The electric spark micro-machining cavity filter with a center frequency of (138.5±3)GHz, insertion loss of -4.4dB, the test results showed the filter has the band-pass characteristics and filter function in 140GHz. In the case of considering the machining error and fixture loss, The main technique indexes basically accord with the design values.