Patent ID: 6496065
Filing Date: 2002-12-17
Classification: H03F

Abstract:
A linear amplifier using a low frequency 2nd intermodulation feed-forwarding method to offset a 3rd intermodulation component of a fundamental signal, the device comprising:a transistor for amplifying a fundamental signal, the transistor having a gate, drain, and an output port; an input impedance matching unit connected to the gate of the transistor for impedance-matching a source of the fundamental signal with the gate of the transistor; a first filter unit, a first end of which is connected to the gate of the transistor, for filtering a 2nd order intermodulation signal from the fundamental signal; a low frequency amplifier connected to a second end of the first filter unit, for amplifying the 2nd order intermodulation signal with a voltage gain; a second filter unit connected in series between an output port of the low frequency amplifier and the drain of the transistor, for filtering the amplified 2nd intermodulation signal and feeding the amplified 2nd intermodulation signal after filtering to the output port of the transistor; and an output impedance matching unit connected to the output port of the transistor for impedance-matching the output port of the transistor with an external load.