Optimum power transfer in RF front end systems using adaptive impedance matching technique

Mohammad Alibakhshikenari; Bal S Virdee; Leyre Azpilicueta; Chan H See; Raed Abd-Alhameed; Ayman A Althuwayb; Francisco Falcone; Isabelle Huynen; Tayeb A Denidni; Ernesto Limiti

doi:10.1038/s41598-021-91355-4

Optimum power transfer in RF front end systems using adaptive impedance matching technique

Sci Rep. 2021 Jun 3;11(1):11825. doi: 10.1038/s41598-021-91355-4.

Authors

Affiliations

¹ Electronic Engineering Department, University of Rome "Tor Vergata", Via Del Politecnico1, 00133, Rome, Italy. alibakhshikenari@ing.uniroma2.it.
² Center for Communications Technology, London Metropolitan University, London, N7 8DB, UK.
³ School of Engineering and Sciences, Tecnologico de Monterrey, 64849, Monterrey, NL, Mexico.
⁴ School of Engineering and the Built Environment, Edinburgh Napier University, Edinburgh, EH10 5DT, UK.
⁵ Faculty of Engineering and Informatics, University of Bradford, Bradford, BD7 1DP, UK.
⁶ Department of Electrical Engineering, College of Engineering, Jouf University, Sakaka, 72388, Aljouf, Saudi Arabia.
⁷ Electronic and Communication Engineering Department, Public University of Navarre, 31006, Pamplona, Spain.
⁸ Institute of Smart Cities, Public University of Navarre, 31006, Pamplona, Spain.
⁹ Institute of Information and Communication Technologies, Electronics and Applied Mathematics, Université Catholique de Louvain, Ottignies-Louvain-la-Neuve, Belgium.
¹⁰ Institut National de la Recherche Scientifique (INRS), Université du Quebec, Montreal, QC, H5A 1K6, Canada.
¹¹ Electronic Engineering Department, University of Rome "Tor Vergata", Via Del Politecnico1, 00133, Rome, Italy.

Abstract

Matching the antenna's impedance to the RF-front-end of a wireless communications system is challenging as the impedance varies with its surround environment. Autonomously matching the antenna to the RF-front-end is therefore essential to optimize power transfer and thereby maintain the antenna's radiation efficiency. This paper presents a theoretical technique for automatically tuning an LC impedance matching network that compensates antenna mismatch presented to the RF-front-end. The proposed technique converges to a matching point without the need of complex mathematical modelling of the system comprising of non-linear control elements. Digital circuitry is used to implement the required matching circuit. Reliable convergence is achieved within the tuning range of the LC-network using control-loops that can independently control the LC impedance. An algorithm based on the proposed technique was used to verify its effectiveness with various antenna loads. Mismatch error of the technique is less than 0.2%. The technique enables speedy convergence (< 5 µs) and is highly accurate for autonomous adaptive antenna matching networks.