Patent ID: 6668165
Filing Date: 2003-12-23
Classification: H03F,H03H

Abstract:
An amplifier comprising:a first circuit having a variable transconductance part and a frequency control part, and being capable of oscillating to generate an output signal in response to an input signal from an antenna; and a controller for controlling the operating state of the first circuit between oscillation and close to oscillation so that high gain, narrowband signal amplification occurs, having: a circuit for generating an error signal through a comparison of the output signal of the first circuit and a Q reference level; a first filter for filtering the error signal to hold the first circuit at a desired Q; a circuit for generating a quenching signal of a sample rate for a quenched operation of the first circuit; a circuit for generating a resulting signal through a multiplication of the filtered error signal and the quenching signal and applying the resulting signal to the transconductance part to control transconductance; a circuit for generating a driving signal through a comparison of the output signal of the first circuit and a reference frequency; and a second filter for filtering the driving signal and applying the filtered driving signal to the frequency control part, a filtering bandwidth being narrow relative to the signal bandwidth if the filtering is active during a matched Q portion with the quench cycle.