Patent ID: 7098747

Claim:
A precision tunable voltage controlled oscillator (VCO) comprises: a bias transistor having a gate, a drain, and a source, wherein the gate of the bias transistor is operably coupled to a bias voltage and the source of the bias transistor is operably coupled to a power supply source; a first inductor having a first node and a second node, wherein the first node of the first inductor is operably coupled to the drain of the bias transistor; a second inductor having a first node and a second node, wherein the first node of the second inductor is operably coupled to the drain of the bias transistor; a first input transistor having a gate, a drain, and a source, wherein the drain of the first input transistor is operably coupled to the second node of the first inductor to provide a first leg of a differential output oscillation of the precision tunable VCO; a second input transistor having a gate, a drain, and a source, wherein the drain of the second input transistor is operably coupled to the second node of the second inductor to provide a second leg of the differential output oscillation, wherein the source of the first input transistor is operably coupled to the source of the second input transistor and to ground, wherein the gate of the second transistor is operably coupled to the first leg of the differential output oscillation and the gate of the first transistor is operably coupled to the second leg of the differential output oscillation; a first capacitor having a first node and a second node, wherein the first node of the first capacitor is operably coupled to receive a control voltage and the second node of the first capacitor is operably coupled to the first leg of the differential output oscillation; a second capacitor having a first node and a second node, wherein the first node of the second capacitor is operably coupled to receive the control voltage and the second node of the second capacitor is operably coupled to the second leg of the differential output oscillation; a first precision tune capacitor circuit operably coupled to the first leg of the differential output oscillation, wherein the first precision tune capacitor circuit provides a first precision capacitance value based on a calibration signal, in which a range of the first precision capacitance value selected is to maintain a precision tuning range of approximately 0.5%; and a second precision tune capacitor circuit operably coupled to the second leg of the differential output oscillation, wherein the second precision tune capacitor circuit provides a second precision capacitance value based on the calibration signal, in which a range of the second precision capacitance value selected is to maintain a precision tuning range of approximately 0.5%, wherein the control voltage, the first precision capacitance value, the second precision capacitance value, the first capacitor, the second capacitor, the first inductor, and the second inductor establish frequency of the differential output oscillation.