Patent ID: 6774736
Filing Date: 2004-08-10
Classification: H03B,H03C,H03J,H03L

Abstract:
A device comprising:a voltage-controlled oscillator (VCO) circuit, the VCO circuit comprising: a) a variable capacitor for coarsely tuning the VCO circuit, the variable capacitor providing one of a plurality of capacitance values, each of the plurality of capacitance values corresponding to a distinct frequency band, each of the plurality of capacitance values providing a frequency/voltage characteristic for the VCO that is sufficiently linear to implement direct modulation for the frequency band, wherein the variable capacitor is a plurality of switchable capacitors, each capacitor coupled to a binary switch that allows the capacitor to be turned on or off; b) a varactor for fine tuning the VCO circuit; and c) a series capacitor having a capacitance value to linearize a frequency/voltage characteristic of the varactor sufficient to implement direct modulation for a specified channel frequency within the frequency band.