Patent ID: 7812672
Filing Date: 2010-10-12
Classification: H03F

Abstract:
1. A low noise amplifier, comprising: a first transistor to receive an input signal at a control terminal; a second transistor configured to couple a first terminal to a second terminal of the first transistor and to provide an amplifier output signal; an envelope detector to output a signal representative of the input signal; and an envelope amplifier to amplify the signal of the envelope detector to apply to a control terminal of the second transistor, wherein a gain of an envelope path β of the envelope amplifier is β=−g.sub.3/(λ.g.sub.1), where λ is a channel length modulation coefficient, g.sub.1 and g.sub.3 are respectively a first order coefficient and a third order coefficient of a polynomial when a non-linearity of an output to an input of the first transistor is represented as the polynomial.