Practical applications of universal approach for calculating maximum transfer efficiency of MIMO-WPT system

• Published in: Wireless power transfer Vol. 7; no. 1; pp. 86 - 94
• Main Authors: Yuan, Qiaowei, Aoki, Takumi
• Format: Journal Article
• Language: English
• Published: Cambridge Cambridge University Press 01.03.2020
• Subjects: Efficiency; Eigenvalues; Impedance matrix; Load; MIMO communication; Misalignment; Receivers & amplifiers; Receiving; S matrix theory; System effectiveness; Transmitters; Wireless power transmission
• DOI: 10.1017/wpt.2020.7
• ISSN: 2052-8418

In this paper, a concise and universal method to calculate the maximum RF (radio frequency) power transfer efficiency between arbitrary multiple transmitters and multiple receivers wireless power transfer (MIMO-WPT) system is presented. The method is based on maximum Rayleigh quotient which can be deduced either from the multi-port impedance matrix Z or from the multi-port scattering matrix S. Moreover, without any limitation on the transmitting/receiving element's geometry, numbers, operating frequency, coupling method, and so on, the approach is capable to evaluate both the transfer efficiency and the maximum transfer efficiency (MTE) of any type of transmitting and receiving elements, and to obtain the optimum impedances for all transmitting or receiving ports as well. At the end of this paper, the MTEs of some typical MIMO-WPT systems will be calculated to validify the proposed method, and the effectiveness against the receiver's misalignment by using multiple transmitters will be demonstrated.