Patent ID: 7427894

Claim:
A radio frequency (RF) amplifier for providing an output signal to a load, the RF amplifier comprising: a first impedance transformation network having an input and having an output connected to the load; an output amplifier stage having an input and having an output connected to an input of the first impedance transformation network; a driver amplifier stage adapted to receive an RF input signal and to amplify the RF input signal; and a switching circuit adapted to provide the amplified RF signal to the input of the output amplifier stage in response to a mode select signal having a first state indicating a first mode, and adapted to provide the amplified RF signal to the input of the first impedance transformation network in response to the mode select signal having a second state indicating a second mode, wherein the output amplifier stage is turned on when the mode select signal has the first state, and is turned off when the mode select signal has the second state, wherein the first impedance transformation network presents to the output amplifier stage a first load impedance at a frequency of the amplified RF signal when the mode select signal has the first state, and wherein the switching circuit presents to the driver amplifier stage a second load impedance at the frequency of the amplified RF signal when the mode select signal has the second state, where the second load impedance is greater than the first load impedance.