Patent ID: 8253496

Claim:
A radio frequency (RF) amplifier circuit, comprising: a first impedance matching circuit configured to receive an input RF signal; a control circuit configured to produce a band control signal according to the frequency of the input RF signal; an RF amplifier having its input connected to the first impedance matching circuit, wherein the RF amplifier is configured to produce an amplified RF signal in response to the input RF signal; a second impedance matching circuit configured to receive the amplified RF signal from the RF amplifier, wherein at least one of the first impedance matching circuit and the second impedance matching circuit has an impedance that is adjustable by the band control signal; and a multi-band filter comprising a plurality of selectable narrow-band filters, wherein the multi-band filter is configured to direct the amplified RF signal from the second impedance matching circuit to one of the selectable narrow-band filters in response to the band control signal.