Semtech Corporation
Capacitive proximity sensor in a mobile device and method of limiting radiation absorption

Abstract:

A proximity sensor for detecting proximity of a body portion to a mobile device, comprising: a plurality of capacitive sensing electrodes for detecting said body portion, an electronic processing circuit arranged for measuring the capacities of said capacitive sensing electrodes and for generating a proximity signal based on the capacities so measured, wherein the capacitive sensing electrodes are connected together by one or more capacitive elements, and at least one capacitive sensing electrode is connectable to a radio circuit of said mobile device so as to constitute a radiofrequency antenna of said mobile device.