Voltage-controlled oscillator with gain proportional to operating frequency

An oscillator circuit, the circuit comprising:

• a voltage-controlled oscillator (VCO) having an output frequency FVCO and a gain KVCO that is proportional to the output frequency FVCO;
• a current scaling block for generating a VCO bias current ICELL that is input to the VCO, the current scaling block having a scaling factor A;
• a reference current source for generating a VCO reference current IFIXED;
• a voltage to current (V/I) converter for converting a control voltage VCTRL into a VCO control current IGM;
• and
• a summing node for coupling the VCO control current IGM and the VCO reference current IFIXED into the current scaling block in such a way that the VCO control current IGM is scaled by the same scaling factor as the VCO reference current IFIXED, wherein the VCO bias current ICELL is the sum of the VCO reference current IFIXED scaled by the scaling factor A and the VCO control current IGM scaled by the scaling factor A, wherein the output frequency FVCO is based on the VCO bias current ICELL.

A phase-locked loop (PLL) circuit, comprising:

• a phase/frequency detector (PFD);
• a filter coupled to the output of the PFD;
• and
• a voltage-controlled oscillator (VCO) coupled to the filter and the output of the PFD in such a way that a feedback path exists between the VCO and the PFD, the VCO generating an output frequency FVCO that is proportional to a VCO input voltage VLF provided by the filter, wherein the VCO has a gain KVCO that is proportional to the output frequency FVCO, and wherein the VCO includes circuitry that couples a VCO control current IGM and a VCO reference current IFIXED and scales the sum of the coupled currents to form a bias current ICELL that adjusts the output frequency FVCO of the VCO.