Patent ID: 7164325

Claim:
An integrated circuit (IC) temperature compensated Voltage Controlled Oscillator (VCO), comprising: a semiconductor substrate; an oscillator manufactured on the substrate and having a variable frequency resonant circuit, the frequency of the resonant circuit controlled, in part, based on a control voltage applied to at least one varactor diode; a first variable voltage source manufactured on the substrate configured to substantially compensate for a temperature sensitive frequency drift attributable to the at least one varactor; and a second variable voltage source manufactured on the substrate configured to substantially compensate for a temperature sensitive frequency drift attributable to the at least one varactor, wherein the variable frequency resonant circuit comprises: a fixed value inductor manufactured on the substrate and having a first end and a second end; a first pair of varactor diodes having a common anode connection, and a cathode of a first varactor of the first pair of varactor diodes coupled to the first end of the fixed value inductor and a cathode of a second varactor of the first pair of varactor diodes coupled to the second end of the fixed value inductor, the common anode connection of the first pair coupled to an output of the first variable voltage source; a second pair of varactor diodes having a common anode connection distinct from the common anode of the first varactor diode pair, and a cathode of a first varactor of the second pair of varactor diodes coupled to a cathode of the first varactor of the first varactor diode pair and a cathode of a second varactor of the second pair of varactor diodes coupled to the cathode of the second varactor of the first varactor diode pair, the common anode connection of the second pair coupled to an output of the second variable voltage source; a first coupling capacitor configured to couple the cathode of the first varactor to the first end of the fixed value inductor; and a second coupling capacitor configured to couple the cathode of the second varactor to the second end of the fixed value inductor.