利用复合左右手传输线设计任意双频微带分支线定向耦合器

该文对基于复合左右手传输线(CRLH-TLs)的双频技术进行了改进，控制设计参数，使其在任意两个工作频率的相位响应分别为和，并用它设计了一个可同时工作在0.9GHz和1.8GHz的微带分支线定向耦合器(BLC)。仿真及实验结果表明：若其它参数保持不变，文中给出的双频微带BLC只与工作在0.9GHz的传统单频BLC尺寸相当，比前人利用CRLH-TLs结构实现的双频BLC尺寸显著减小。这在一定程度上解决了双频工作与结构紧凑性之间的矛盾，具有一定的工程应用价值。

Arbitrary Dual-band Microstrip Branch-line Coupler Using Composite Right/Left-handed Transmission Lines

The Dual-band technique based on Composite Right/Left Handed (CRLH) Transmission Lines (TLs) is improved in this paper. By properly choosing the parameters of the CRLH-TLs, the structure will yield electrical length and at the two operating frequencies. Employing this structure, an arbitrary dual-band microstrip Branch-Line Coupler (BLC) operating at 0.9GHz and 1.8GHz is achieved. Simulated and measured results demonstrate that when the rest of the parameters are unchanged, this BLC is significantly more compact compared to the CRLH approach proposed before, and as small as that of the conventional BLC based on quarter-wavelength TLs with single operating frequency at 0.9GHz. The proposed method can mitigate some of the problems between the dual-band work and the need for compact size, which is of great use in practical applications.