基于复合左右手传输线的移相器设计

Abstract

本文利用复合左右手传输线特殊的非线性相位响应特性，提出一种宽带移相器的设计方法。宽带移相器的使用可以控制天线波束在宽带内实现较固定的倾角。该方法由主副两个通路组成四端口的差分移相，其中主通路由复合左右手传输线组成，副通路由传统的右手传输线构成。两通路在很宽的带宽内相位变化一致，能够实现宽带移相。通过HFSS软件仿真设计出90˚移相器，在8~15.9 GHz (66.4%)带宽内相位不平衡度为±3˚，带内回波损耗 < −12 dB，最大插入损耗为0.3 dB。该结构设计简单，加工方便。 A design of broadband phase-shifter is presented by utilizing the unique nonlinear phase response of the composite right-left handed transmission line. The use of wideband phase-shifter can control antenna beam to achieve a fixed angle in broadband. The four-port differential phase- shifter consists of two paths, one path using composite right-left handed transmission line while the other using conventional right hand transmission line. A stable phase difference can be obtained over a wide bandwidth, so that broadband phase shift can be achieved. Simulated results show that the 90˚, phase-shift with phase imbalance of ±3 can be achieved over a broad bandwidth from 8 GHz to15.9 GHz (66.4%), with the return losses more than 12 dB and the insertion losses less than 0.3 dB. Moreover, the proposed structure is easy to design and convenient to fabricate.