Patent ID: 7808312

Claim:
A broad-band linear amplifier circuit, comprising: a driver amplifier configured, under the control of a bias signal, to produce a first amplified radio frequency (RF) signal in response to an input RF signal of a first RF frequency and to produce a second amplified RF signal in response to an input RF signal of a second RF frequency, wherein the first RF frequency is in a first single RF band and the second RF frequency is in a second single RF band, wherein the first single RF band and the second single RF band are not overlapping and reside in a broad band; a power amplifier configured to amplify the first amplified RF signal to produce a first output RF signal and to amplify the second amplified RF signal to produce a second output RF signal; a sensing circuit configured to sense at least one of a power, a gain, or a phase of the first output RF signal and the second output RF signal, and to produce a sensing signal; a biasing circuit configured to produce the bias signal in response to the sensing signal; a gain control circuit configured to control gain variation of the driver amplifier in response to the sensing signal; and a multi-band filter comprising a first selectable narrow-band filter and a second selectable narrow-band filter, wherein the first selectable narrow-band filter is configured to produce a first RF output signal in the first single RF band in response to the first amplified radio RF signal, wherein the second selectable narrow-band filter is configured to produce a second RF output signal in the second single RF band in response to the second amplified radio RF signal.