一种新型毫米波差分线和基片集成波导结构转换设计

Design of a Novel Millimeter-Wave Differential Lines-Substrate Integrated Waveguide Transition

差分线和基片集成波导(Substrate Integrated Waveguide,SIW)结构由于各自显著的优势,在毫米波系统中得到广泛研究和应用。为了实现毫米波系统高度集成化,提出一种新型毫米波段差分线转基片集成波导结构。为实现工程系统中的通用性,差分线的输入端与射频前端的输出端呈一定夹角,这将导致共模噪声增大,插损恶化,结构体积增大,匹配结构的设计难度增大。通过差分线的过渡结构转角设计以及SIW结构的模式转换设计,在结构上实现了45°夹角的差分传输线输入、射频前端垂直输出,在性能上实现了转换结构的高共模噪声抑制比。对该转换结构进行了建模分析和加工测试,在68~80 GHz频段内,输入、输出端口的回波损耗高于10 dB,插入损耗低于3.39 dB。

Differential lines and substrate integrated waveguide(SIW)structure have been widely studied and applied in millimeter-wave systems due to their significant advantages.To realize the high integration of millimeter-wave system,a novel millimeter-wave band differential lines-SIW transition is proposed.In order to achieve the generality of the engineering system,the differential pairs as the input end has a certain angle with the output end of the radio frequency(RF)front end,which leads to the increase of common-mode noise,the deterioration of insertion loss,the increase of structure volume,and the increase of the difficulty of matching structure design.The angle of the differential lines-SIW transition structure and the mode conversion of the SIW structure are designed to achieve the input with 45°bend of differential transmission lines and the vertical output of the RF front end in the structure.The high common-mode noise suppression ratio of the transition structure is realized in the performance.The transition structure is modeled,analyzed,fabricated and measured.The return loss is high than 10 dB,and the insert loss is less than 3.39 dB in the working frequency range of 68-80 GHz.