高功率小型化波导E面异频功率合成器的设计

Design of a high-power miniaturized waveguide E-plane heterodyne power combiner

为了满足典型应用场景对高功率异频功率合成器提出的输入输出同向及结构紧凑的需求,提出并设计了一种工作在9.3 GHz和9.7 GHz频率的高功率小型化波导E面异频功率合成器。基于滤波器结构异频功率合成器的原理,通过采用过模矩形波导E面合成的形式,使两个波导滤波器相互平行,两个输入端口相互平齐,以满足特定应用场景的需求。同时,通过减小合成环节的矩形波导尺寸对合成过程中产生的高次模进行抑制,并按照半个波导波长的整数倍减小波导滤波器模片间距,在保证具有高功率容量的前提下缩短了滤波器长度。设计的异频功率合成器整体长度为9.2λ,宽度为1.5λ,高度为2.8λ(λ为9.5 GHz所对应的自由空间波长)。仿真结果表明,该合成器在9.3 GHz和9.7 GHz频率下的回波损耗均大于20 dB,合成效率大于98%,输入端口之间的隔离度大于20 dB,在80 MV/m微波脉冲击穿阈值下,功率容量为310 MW。

The existing heterodyne power combiners are not suitable for applications where input and output signals need to be in the same direction with limited space.To solve the problem,this paper designs a high-power and miniaturized heterodyne power combiner operating at frequencies of 9.3 GHz and 9.7 GHz.Based on the traditional filter-based heterodyne power combiner,the proposed design utilizes an over-mode rectangular waveguide E-plane power combiner.The waveguide filters are parallel and the input ports are also located on the same plane,so that the combiner is suitable for the specific applications.The sizes of the rectangular waveguide are reduced to suppress higher-order modes.Besides,the distance between mode strips is decreased in integer multiples of half-wavelength of the waveguide to compresses the overall length with high power capacity.The combiner has a length of 9.2λ,a width of 1.5λand a height of 2.8λ,whileλis the wavelength corresponding to the frequency of 9.5 GHz in free space.At 9.3 GHz and 9.7 GHz,the return loss of the combiner is more than 20 dB,its combining efficiency is more than 98%,and the isolation between input ports is more than 20 dB.At microwave pulse breakdown threshold of 80 MV/m,the combiner provides a power capacity of 310 MW.