System and method for selectively providing security to and transmission power from a portable electronic device depending on a distance between the device and a user

Abstract

A portable electronic device is provided for sending and receiving a communication signal to and from a target, respectively. Among other components, the portable electronic device includes an antenna, a transceiver, a signal processing system and control circuitry. The signal processing system determines a distance between the target and the portable electronic device. There are various ways to determine the relative distance between the target and the device. One such methodology is to use a change in a signal that is transmitted from the transceiver and reflected from the target back to the transceiver. The change can be a frequency shift, a phase shift, a capacitive coupling change, an impedance change, or any other change which notes the presence of a target relative to the transceiver. The control circuitry may be used to change the amount of power applied to the antenna and/or to change at least one security measure of the device depending on the distance detected between the target and the device.

Dependencies are inferred from the claim text.