Inventors:
Gustavo D. Leizerovich - Miami Lakes FL
Dennis G. Anson - Coral Springs FL
Assignee:
Motorola, Inc. - Schaumburg IL
International Classification:
H01Q 136
Abstract:
A communication unit (200) employs a method and apparatus for increasing an output impedance of a transmit amplifier during a receive mode of the communication unit. The communication unit includes a transmit amplifier, an antenna (209), and a signal receiver (211), and is operable in at least a transmit mode and a receive mode. During the transmit mode, the transmit amplifier, which includes an amplifying device (201), amplifies an input signal (221) and provides the amplified signal (233) to the antenna for transmission. During the receive mode, the antenna receives signals and provides the received signals to the signal receiver. To mitigate the transmit amplifier's effect on the received signals during the receive mode, the communication unit, during the receive mode, couples the transmit amplifier to the antenna and applies a bias (225) to the amplifying device to increase the output impedance (Z. sub. out) of the transmit amplifier, such that the transmit amplifier does not significantly load the received signals.