Tuning Methods for Wireless Power Transfer in Biomedical Device

Abstract

This paper presents tuning methods on a Class-E power amplifier for a wireless power transfer (WPT) system based on resonant inductive coupling. In this paper, the scope of research is focusing on providing a stable power for Wireless Capsule Endoscopy (WCE). Shifting of the resonance frequency of a WPT system is unavoidable mainly due to various factors including variations in its working environments. This reduces the performance of WPT system leading to inconsistent voltage at the receiver. To overcome this problem, two tuning approaches namely frequency tuning and voltage tuning are proposed. The Frequency tuning method works to tune the power amplifier circuit so that it operates at the frequency close the resonant frequency of the transmitter which is also ensured the optimal switching condition in the driving circuit. The voltage tuning helps to regulate the receiver’s voltage output to make it stable and constant. Our experimental results indicate that the proposed approach has improved the performance of the WPT.