一种E波段耦合微带线和矩形波导转换的设计

Design of a Structure Transforming from E-band Coupled Microstrip Line to Rectangular Waveguide

耦合微带线是毫米波中常用的一种平面传输线,其差模可以有效地减少电路间的耦合,并改善平面传输线的表面波问题,但耦合微带线不便于直接测试其性能。针对此问题,设计了一个耦合微带线和矩形波导的转换结构,能够将耦合微带线的差模转换成矩形波导的主模TE10,同时具有很高的共模抑制。该转换结构在74~77 GHz附近的性能很好,驻波比在1.2以下,插入损耗小于1 dB。该转换结构可以用来测量差模馈电的微波器件和天线。

The coupled microstrip line is a kind of planar transmission line,which is commonly used in millimeter wave.The differential mode can effectively reduce the coupling between circuits and mitigate the surface wave problem of the planar transmission line,but the coupled microstrip line is not convenient to test its characteristic directly.In order to solve this problem,a structure transforming coupled microstrip line to rectangular waveguide is designed.The transformation can convert the differential mode of the coupled microstrip line to the fundamental mode TE10 of the rectangular waveguide,while the common mode of the coupled microstrip line is highly suppressed.The transformation structure performs very well near 74~77 GHz.The VSWR of the transformation is below 1.2,and the insertion loss is below 1 dB.The transformation structure can be used to measure the microwave devices and antennas,which are fed by the differential mode signal.