Abstract: A phase-locked-loop circuit for a radio transceiver operative to transmit and to receive modulated signals during nonconcurrent time periods. During time periods in which the radio transceiver is to generate and to transmit a modulated signal, the phase-locked-loop circuit is connected to the transmitter portion of the transceiver. During time periods in which the radio transceiver is to receive a modulated signal, the phase-locked-loop circuit is connected to the receiver portion of the transceiver. A switch, preferably comprised of a multiplexer, alternately connects the phase-locked-loop with the transmitter portion and the receiver portion of the transceiver.

Abstract: The present patent application includes a discussion of a signal compensation apparatus (119). The apparatus is implemented in a digital radiotelephone (101) having diversity receivers (111, 113). The signal compensation apparatus utilizes three control loops and a branch selection switch circuit to substantially diminish the undesired gain and DC offset present in the selected received data signal. Portions of the apparatus are implemented in a digital signal processor (DSP) (249) for rapid adjustment of the control loops when switching to a different receiver branch.

Abstract: The antenna coupling apparatus of the present invention couples an antenna, located in a hinged element (102) of a wireless communication device, to the receiver (401) of the device. In the preferred embodiment, the communication device is a radiotelephone. The coupling is achieved without contact or flexible cable by parallel plate capacitors (201 and 202) in the hinge of the communication device. The capacitors (201 and 202) additionally act as a matching network for the antenna.