Advanced Micro Devices, Inc.
TRANSMITTER DYNAMIC RF POWER CONTROL VIA VSWR DETECTION FOR WIRELESS RADIOS

Abstract:

An electronic device includes a power amplifier that sets the power of a transmit signal that is transmitted via an antenna of the device, and further includes a VSWR detector to identify the VSWR at a signal path between the antenna and the power amplifier. As a person (e.g., a user) moves in close proximity to the antenna, the amount of reflected energy along the signal path increases, thereby increasing the VSWR. A power controller of the electronic device sets a gain of the power amplifier based on the VSWR to ensure that the SAR exposure to the person is maintained below a specified threshold.