ANTENNA ARRAY CALIBRATION FOR WIRELESS CHARGING

摘要

Antenna array calibration for wireless charging is disclosed. In one aspect, an initial calibration sequence is performed each time a wireless charging station is powered on. The initial calibration sequence utilizes a reference antenna element, which is an antenna element randomly selected from a plurality of antenna elements in the wireless charging station, to determine relative receiver phase errors between the reference antenna element and each of the other antenna elements in an antenna array. In another aspect, a training sequence is performed after completing the initial calibration sequence to determine total relative phase errors between the reference antenna element and each of the other antenna elements in the antenna array. Adjustments can then be made to match respective total relative phase errors among the plurality of antenna elements to achieve phase coherency among the plurality of antenna elements for improved wireless charging power efficiency.

主权项

1. A wireless charging station, comprising:
a plurality of antenna elements each comprising:
a receiver and a transmitter coupled to an antenna; anda phase shift circuitry coupled to the transmitter and configured to adjust respective transmitter phase of the transmitter; a calibration antenna element comprising a calibration receiver and a calibration transmitter; and a controller coupled to the plurality of antenna elements and the calibration antenna element, the controller configured to:
select a reference antenna element from the plurality of antenna elements wherein unselected ones of the plurality of antenna elements are non-reference antenna elements;transmit a first calibration signal from a transmitter of the reference antenna element;measure phase ax of the first calibration signal at a receiver of the reference antenna element;measure phase bx of the first calibration signal at the calibration receiver of the calibration antenna element; andfor each of the non-reference antenna elements:
transmit a second calibration signal from a transmitter of a non-reference antenna element;measure phase ay of the second calibration signal at a receiver of the non-reference antennaelement;measure phase by of the second calibration signal at the calibration receiver of the calibration antenna element;transmit a third calibration signal from the calibration transmitter of the calibration antenna element;measure phase cx of the third calibration signal at the receiver of the reference antenna element;measure phase cy of the third calibration signal at the receiver of the non-reference antenna element; anddetermine relative receiver phase error between the non-reference antenna element and the reference antenna element based on the phase ax, the phase bx, the phase cx, the phase ay, the phase by, and the phase cy.