和差网络是毫米波单脉冲雷达前端中的一个重要器件,设计了一种由四个阶梯型波导魔T组成的Ka波段和差网络。相比于传统的波导匹配魔T,该新型魔T由于采用了阶梯型过渡匹配结构,抗振动能力较好。四个魔T按一定方式排列和连接,以使和差端口成一直线分布,四个接收端口成“十冶字型分布,易于系统集成。通过三维电磁仿真软件优化设计,在34 GHz ~36 GHz 范围内,和差器各端口回波损耗大于15 dB,当和端口激励时各输出端口的幅度一致性小于0. 1dB、相位一致性小于5°。最后,给出和差网络的实物测试结果,并与仿真结果对比。

The sum-difference network is an important part of millimeter wave monopulse radar. A monopulse sum-difference network composed of four step-shaped magic tee is proposed at Ka-band. Compared with the conventional waveguide matching magic tee,the newly waveguide magic tee has a better ability to resist vibration because of the step-shaped matching structure. The four magic tee are arranged and connected in a certain way to make the distribution of the four input ports into the shape of a cross and the output ports into the shape of a linear according to the design requirements. Using 3D electromagnetic simulation software to optimize the design,simulation results indicate that the return loss of each port is more than 15 dB from 34 GHz to 36 GHz. When thesum port is excitated,the power difference between the four outout ports is less than 0. 1 dB and the phase difference is less than 5°. Finally,the test results are given and compared with the simulation results.