An Unconventional Measurement Technique to Estimate Power Transfer Efficiency in Series–Series Resonant WPT System Using S-Parameters

Power transfer efficiency is a critical performance parameter for the coil design of a wireless power transfer (WPT) system. An accurate and simplistic measurement technique of power transfer efficiency will ensure the system less susceptible to the external environment with high reliability. Broadly, S-parameter-based efficiency is considered a precise measurement technique attained by the network analyzer. However, it lacks consistency in the practical scenario, being the input-output ports calibrated at 50Ω. Accordingly, most of the power dissipates in the instrument’s internal resistance. Therefore, this paper proposes a novel S-parameter efficiency measurement technique aided by user-calibrated source and load factors. This technique’s output ensures the WPT system’s performance assessment even at high frequencies by S-parameters at all conditions. Besides, the proposed technique is experimentally verified and compared with various conventional techniques employed in several literary works.