| 摘要 |
<p>An antenna tuning apparatus for a portable communications device (10) which includes a means (12) of adapting the device to be worn on the body. The device (10) consists of an antenna (14), tuning means (16) and a receiver for receiving transmitted signals including a tuning mode signal. A decoder (30) initiates antenna tuning when the tuning mode signal is detected. A tuning controller (32) enables a carrier detection circuit (46) to determine the magnitude of the received signals, and generate a tuning control signal supplied to a D/A converter (34) to effect tuning of the antenna (14) by monitoring the variations in the magnitude of the received signals.</p> |
