
改进的宏元胞法及其在一维人工周期传输线色散性能提取中的应用
Improved Macro Cell Method and Its Application in Extraction of Dispersive Characteristics of 1D Artificial Periodic Transmission Lines
针对传统宏元胞法时效性低通用性弱的缺陷,提出了一种改进的宏元胞法,即将相移常数的多值问题转化为对同一周期结构相位解卷绕起始频点的判定问题,如此可方便地提取出唯一精确的相移常数.由于新方法严格考量了元胞间电磁场的互耦效应,仅需一次仿真或实测便可计算出元胞间存在任意耦合强度的一维人工周期传输线的色散和Bloch阻抗性能.运用新方法提取了经典的非平衡态和平衡态互易非对称微带复合左右手传输线的色散特性,并与传统的本征模式法、解卷绕法和单元胞法的提取结果进行了对比.进一步利用改进宏元胞法和解卷绕法的提取结果分别反演出微带复合左右手传输线的S参数,基于改进宏元胞法解的S参数与全波仿真S参数之间良好的一致性证实了新方法的精确性.
In view of the poor time-efficiency and generality of the traditional macro cell method, an improved macro cell method(IMCM)is proposed, capable of extracting the dispersive properties of any 1D reciprocal artificial periodic transmission line(APTL)with finite periodicity.Key to the IMCM lies in that the multiple-root problem of the initially extracted phase shift constant is transferred to the problem of judging the starting frequency of the phase unwrapping, making it easy to determine the uniquely correct phase shift constant.Since the electromagnetic coupling effects among unit cells of a periodic structure are rigorously considered in the IMCM, both the dispersion and Bloch impedance characteristics can be accurately and effectively extracted with simulation or measurement only once, however strong the coupling intensity is.As examples, the proposed IMCM is applied to extract the dispersive properties of the classical reciprocal asymmetric microstrip composite right-/left-handed transmission lines(CRLHTLs)in the unbalanced and balanced states, and the extraction results are compared to those from the traditional eigenmode method, unwrapping method(UPM)and single cell method.Furthermore, S parameters of the microstrip CRLHTL are retrieved using the extraction results of the IMCM and the UPM, and the former S parameters coincide perfectly with the full-wave results, confirming the accuracy of the IMCM.
改进的宏元胞法 / 人工周期传输线 / 色散和Bloch阻抗性能 {{custom_keyword}} /
improved macro cell method / artificial periodic transmission line / dispersion and Bloch impedance characteristics {{custom_keyword}} /
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中央高校基本科研业务费 (No.K5051202007); 国家自然科学基金面上项目 (No.61271017)
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