Gazi Üniversitesi Fen Bilimleri Dergisi (Jun 2017)
Design Of A Resonance Frequency Tracking System For Rf Applications
Abstract
In this work, a resonance frequency tracking system is proposed for general use in RF applications. The proposed system is based on the fact that the minimum input reflection coefficient occurs at the resonance frequencies, and the system consists of a bidirectional coupler, a rectifier and a control unit. The sampled signals from the forward and reflect ports of the bidirectional coupler are taken as an input for the controller unit and the reflection coefficient is calculated by dividing the reflected one to forward one. The control unit systematically changes the source frequency until a minimum reflection coefficient is reached. The frequency that corresponds that minimum reflection coefficient is the instant resonance frequency for the system. After discussing the details of proposed frequency tracking system, the system is applied to a wireless power transfer system based on resonance magnetic coupling. Measurement results of the fabricated circuits and the test results for the control unit are presented.
