Patent attributes
A front end circuit for coupling an antenna to a radio frequency (RF) transceiver is disclosed. An antenna port connectible to the antenna is provided, as well as a power amplifier coupled to a signal output of the RF transceiver and a low noise amplifier coupled to the signal input of the RF transceiver. The front end circuit includes a switching network that is connected to the antenna port, the power amplifier, and the low noise amplifier. Additionally, there is at least one resonant circuit and a control circuit coupled to a receive enable line of the transceiver. This resonant circuit defines a parallel resonance with a first resonant resistance in the operating frequency band upon activation in the receive mode. The resonant circuit also defines a substantially high transistor impedance upon deactivation in the transmit mode.
