差分无源器件的设计

在现代无线通信系统中，差分电路相比单端电路而言具有更强的抗干扰能力，因此受到了国内外学者的广泛关注。文章介绍了混合模散射参数、差分器件设计中常用的微带线和缝隙线及两种传输线之间的相互转化，并介绍了基于微带线和缝隙线转换结构的两种全差分带通滤波器。两种滤波器分别实现了多频段和宽带的差模传输特性以及宽带的共模抑制特性。文章还给出了差分耦合器、差分功分器和差分天线等差分器件的设计。仿真与实测结果吻合较好，验证了设计方法的正确性。

Design of Differential Passive Devices

In modern wireless communication system, differential circuit has stronger anti-interference ability than the single-ended circuit, so it has been widely concerned by scholars at home and abroad. In this paper, mixed mode S-parameters are introduced firstly, and then microstrip line and slotline, which are commonly used in differential device designs, and their mutual transformation are introduced. Two types of fully differential bandpass filters based on microstrip line and slotline conversion structures are presented in this paper. The two filters realize the differential-mode transmission characteristics of multi-band and broadband respectively, and the broadband common-mode suppression characteristic. Finally, the designs of various differential devices such as differential coupler, differential power divider and differential antenna are also given. The simulation results agree well with the measured results, which verify the correctness of the design method.