A Novel Capacitive Coupler Array with Free-Positioning Feature for Mobile Tablet Applications

This letter proposes a novel capacitive coupler array with free-positioning feature for mobile tablet applications. The capacitive coupler consists of three printed circuit boards, two of which constitute the transmitter and the third one is the receiver. The coupler is vertically arranged to make the charging system compact and feasible for mobile tablet applications. By applying a repetitive structure on the transmitter side and properly designing the receiver, free-positioning capacitive charging is realized and the coil-to-coil charging efficiency is not affected by the variation of the receiver position. Only two series inductances are utilized for compensation purposes, which makes the system more compact and easy to be fabricated. This proposed capacitive coupler is studied via finite-element analysis and verified by the experimental results at 1, 2.17, and 3.45 MHz.