Patent ID: 8073401

Claim:
A front end circuit for coupling an antenna to a first radio frequency (RF) transceiver and a second RF transceiver, each of the RF transceivers having a respective one of a signal input, a signal output, a receive enable line and a transmit enable line, the front end circuit comprising: an antenna port connectible to the antenna; a first power amplifier coupled to the signal output of the first RF transceiver, the first power amplifier including a first transmit control circuit coupled to the transmit enable line of the first RF transceiver; a second power amplifier coupled to the signal output of the second RF transceiver, the second power amplifier including a second transmit control circuit coupled to the transmit enable line of the second RF transceiver; a combined low noise amplifier base stage coupled to the signal input of the first RF transceiver and the signal input of the second RF transceiver, and including a base receive control circuit coupled to the receive enable lines of the first RF transceiver and the second RF transceiver; a first low noise amplifier including a first receive control circuit coupled to the receive enable line of the first RF transceiver; a first inter-stage matching circuit coupling the combined low noise amplifier base stage to the first low noise amplifier; a second low noise amplifier including a second receive control circuit coupled to the receive enable line of the second RF transceiver; a second inter-stage matching circuit coupling the combined low noise amplifier base stage to the second low noise amplifier stage; and a matching network coupled to the antenna port, the first power amplifier, the second power amplifier, the first low noise amplifier and the second low noise amplifier, outputs of the first power amplifier and the second power amplifier and inputs of the first low noise amplifier and the second low noise amplifier all being common; wherein a corresponding enable signal applied to a one of the first transmit enable line, the second transmit enable line, the first receive enable line, and the second receive enable line activating and setting a bias point of the corresponding one of the first power amplifier, the second power amplifier, the first low noise amplifier, and the second low noise amplifier.