This article presents a novel differential‐to‐single‐ended (DS) crossover by using two rings included of controllable frequency ratio of composite right‐ and left‐handed (CRLH) transmission lines for dual‐band applications. To reject the out‐of‐band differential‐mode transmission coefficient, two dumbbell‐shaped defected ground resonators (DGRs) are utilized over the differential transmission lines. Theoretical analysis proves that the frequency ratio can be controlled by choosing the number of designing CRLH cells and the parameter values appropriately. Also, desired electrical lengths and impedances of DGRs were obtained at the bandstop notch of differential‐mode transmission coefficient by conducting common‐ and differential‐mode analysis of lumped element equivalent circuit. To validate the proposed structure, two fabricated prototypes including the DS crossover designing at 1.8 and 4.2 GHz and separate differential lines with embedded DGRs were fabricated and measured. Measurement mixed‐mode results exhibit that the fabricated crossover has great results at both frequency bands and has a good out‐of‐band differential insertion loss rejection.

中文翻译：

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基于哑铃形缺陷接地谐振器的差分到单端分频，用于双频应用

本文介绍了一种新颖的差分至单端（DS）分频器，它通过使用两个环来控制双频复合右手和左手（CRLH）传输线的频率比。为了拒绝带外差分模式传输系数，在差分传输线上使用了两个哑铃形缺陷接地谐振器（DGR）。理论分析证明，该频率比可以通过适当地选择设计CRLH单元和参数值的数量来控制。另外，通过对集总元件等效电路进行共模和差模分析，可以在差模传输系数的带阻陷波处获得所需的DGR的电气长度和阻抗。为了验证提议的结构，制作并测量了两个制造的原型，包括在1.8 GHz和4.2 GHz处的DS交叉设计以及带有嵌入式DGR的独立差分线。测量混合模式结果表明，制造的分频器在两个频带上均具有出色的结果，并且具有良好的带外差分插入损耗抑制能力。