基片集成波导宽带四路滤波功分器的设计

Design of broadband four-way filter power divider based on substrate integrated waveguide

根据基片集成波导(substrate integrated waveguide,SIW)和传统矩形波导的等效关系,设计了一款基于SIW结构小型化的宽带四路滤波等功分器。通过同轴线在波导中心馈电,输出端口采用微带输出的方式,且输出等幅同相。四排金属孔将波导平均分成4个腔,腔体中同时存在3种模式(TE101/TE102/TE201),实现三模带通;利用感性孔的微扰抑制高次模(TE202),提高阻带性能。实测工作带宽不小于2.5GHz,中心频率10GHz。该四路滤波功分器具有体积小、制作简单、方便与其他电路集成等优势。

According to the equivalent relation between the substrate integrated waveguide and conventional rectangular waveguide,a compact wideband four-way equal filter power divider is designed based on substrate integrated waveguide（SIW）.The design uses coaxial feed in the center.SIW-to-microstrip transitions are used for the output ports with equal amplitude and phase.The four-row metal holes are used to divide the waveguide into four cavities on average.In the pass-band,there are three modes（TE101/TE202/TE303）in the cavities,which can realize tri-mode bandpass.The high order mode（TE202）is suppressed by the perturbation of the inductive hole,and the stop band performance is improved.Measured results of the filter power divider have shown that the bandwidth is more than 2.5 GHz at centre frequency of 10 GHz.The four-way filter power divider has the advantages of small size,simple manufacture,easy integration with other circuits,etc.