公开(公告)号：US10063087B2

公开(公告)日：2018-08-28

申请号：US15138322

申请日：2016-04-26

Applicant: NXP B.V.

Inventor： Robert Glenn Il Crosby ,  Peter Christiaans ,  Qiong Wu

IPC: H02J7/00 ,  H02J7/02 ,  H02J50/12

CPC classification number: H02J7/025 ,  H02J50/10 ,  H02J50/12

Abstract: A wireless charging receiver operates on a resonance principle and includes an impedance matching circuit coupled between an antenna and a rectifier circuit. The impedance matching circuit has both series-connected and parallel-connected capacitors. At least one of the capacitors is a tunable variable capacitor. A method is provided for automatically adjusting a capacitance value of the at least one variable capacitor based on an error voltage between a target rectifier voltage and a measured rectifier voltage. Automatically adjusting the antenna impedance of the receiver provides for improved power transfer efficiency for changing operating conditions. In one embodiment, one or more of the parallel-connected capacitors are variable capacitors. In another embodiment, one or more of the series-connected capacitors are variable capacitors.