Apple Inc.
Circuit, transmission system and method for determining proximity of an object

Abstract:

A circuit includes a sensing circuit for a first antenna and a second antenna, the sensing circuit including an adjustable characteristic that is based on a proximity of an object to the first or second antenna used to transmit a transmit signal. An evaluation circuit is coupled to the sensing circuit. The evaluation circuit is configured to monitor the characteristic of the sensing circuit and to determine whether the characteristic fulfills a predetermined criterion.