Patent ID: 6307442
Filing Date: 2001-10-23
Classification: H03H,H03J

Abstract:
A tunable electronic filter circuit comprising:an input terminal;an output terminal connected to the input terminal with a node therebetween;a variable capacitor coupled between the node and a common ground reference;an inductor coupled between the node and the common ground reference;a resistor coupled between the node and the common ground reference;a feedback control circuit coupled to the variable capacitor, the feedback control circuit operable to tune the variable capacitor in order to set a predetermined frequency of the electronic filter circuit, wherein the feedback control circuit includes a quality factor calibration loop, wherein the quality factor calibration loop includes a peak detector;whereby when an input signal is applied to the input terminal, the electronic filter circuit passes an output signal to the output terminal which includes components of the input signal within a predetermined frequency bandwidth set by the predetermined frequency while substantially filtering out other components of the input signal.