基于扇形枝节的Ka波段带通滤波器设计

Design of Ka Band Bandpass Filter Based on Radial Stub

【目的】在通信系统中,滤波器对滤除带外信号有着重要的作用。对于传统的平行耦合线滤波器和发夹线滤波器来说,存在体积较大以及寄生通带的问题。【方法】使用微带扇形枝节设计出一个小尺寸Ka波段带通滤波器。首先针对扇形枝节结构进行分析计算,然后使用全波三维电磁仿真软件对滤波器进行建模仿真,并通过调整扇形枝节的半径和角度等参数,对初始模型进行优化改进。最后使用RO5880基板对滤波器进行加工。【结果】实际测试得到滤波器中心频率约36.9 GHz,带宽约为4.57 GHz,达到了设计指标。【结论】本设计相较于同频段的平行耦合线滤波器占用更小的体积,且在低频段对带外信号的抑制效果更好。

【Purposes】In communication systems,filters play an important role in filtering out-of-band signals.For the traditional parallel coupled line filter and clip line filter,the size is large and the parasitic pass band problems exist.【Methods】A small Ka band pass filter is designed by using radial stub.In this paper,the radial is analyzed,calculated,and simulated.Then,the filter is modeled and simulated with HFSS.According to the simulation results,the initial model is optimized and improved by adjusting the radius and angle of the radial stub.Finally,the filter is processed by using RO5880 substrates.【Findings】The actual test results show that the center frequency of the filter is about 36.9 GHz and the bandwidth is about 4.57 GHz,which reashes the parameter requirements.【Conclusions】Compared with parallel coupled line filters,this design occupies less volume in the same frequency band,and has better suppression effect on out-of-band signals in the low frequency band.