A Novel Tuning Method for Impedance Matching Network Based on Linear Fractional Transformation

作     者：Xiong, Botao Yang, Lei Cao, Tao 

作者机构：China Acad Engn Phys Inst Elect Engn Mianyang 621000 Sichuan Peoples R China 

出 版 物：《IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS》 (IEEE Trans. Circuits Syst. Express Briefs)

年 卷 期：2020年第67卷第6期

页      面：1039-1043页

核心收录：

学科分类：0808[工学-电气工程] 08[工学] 

基　　金：National Natural Science Foundation of China 

主　　题：Linear fractional transformation detector for the sign of S-11 binary search algorithm 

摘      要：Correction of antenna impedance variation in real time with low cost is a challenge. We propose two criteria with the aid of linear fractional transformation (LFT) to fulfill the pre-requirements of binary search scheme. Compared with gradient descent-based algorithms, the convergence speed is improved from O(N) to O(logN) at the cost of expensive impedance sensor. To reduce the hardware cost and computational complexity of feedback circuits, the binary search scheme is optimized so that only the detection of the sign of real part and imaginary part of S-11 is required. As a result, compared with the impedance sensor, no analog to digital converters (ADCs) and digital calculations are required for the proposed feedback loop. In the end, the proposed scheme is validated with an electromagnetic simulation.