Frequency generator and gain calibration technique for two-point modulation in a phase-locked loop

A non-transitory computer-readable medium having stored thereon computer-executable instructions that when executed by one or more computing devices cause the one or more computing devices to perform operations for determining a gain of a voltage controlled oscillator (VCO) in a phase lock loop (PLL) configured for a two-point modulation scheme, the operations comprising:

• directing the voltage controlled oscillator (VCO) in the phase lock loop (PLL) via a first input to produce a desired output frequency while a feedback loop of the PLL is open;
• applying a first control signal to a second input of the VCO;
• configuring an array of capacitors in the VCO;
• measuring the output frequency of the VCO responsive to the first control signal;
• applying a second control signal to the second input of the VCO;
• measuring the output frequency of the VCO responsive to the second control signal;
• and
• determining the gain of the VCO as a function of output frequencies responsive to voltage values applied at the second input of the VCO.

A non-transitory computer-readable medium having stored thereon computer-executable instructions that when executed by one or more computing devices cause the one or more computing devices to perform operations for calibrating a transceiver configured to apply a two-point modulation scheme, the operations comprising:

• directing a voltage-controlled oscillator (VCO) in a phase look loop (PLL) to generate a desired output frequency by applying a desired voltage at a low-pass data input to the VCO while a feedback path in the PLL is open;
• applying a first control signal to a high-pass data input of the VCO, the first control signal resulting in a first tuning voltage;
• configuring an array of capacitors in the VCO;
• measuring a first frequency at an output of the VCO, the first frequency corresponding to the first tuning voltage;
• applying a second control signal different from the first control signal to the high-pass data input of the VCO, the second control signal resulting in a second tuning voltage;
• measuring a second frequency at the output of the VCO, the second frequency corresponding to the second tuning voltage;
• determining the gain of the VCO as a function of the difference of the second frequency and the first frequency and the difference of the second tuning voltage and the first tuning voltage;
• and
• adjusting a transceiver in response to the gain of the VCO prior to transmitting data from the transceiver.

A method for measuring the gain of a voltage-controlled oscillator (VCO) in a phase-locked loop (PLL) configured to apply a two-point modulation scheme, the method comprising

• opening a feedback path in the phase-locked loop (PLL) having the voltage-controlled oscillator (VCO);
• receiving at a first circuit element of the VCO a low-pass tuning voltage to generate a desired frequency at an output of the VCO while the feedback path is open;
• and
• receiving at a second circuit element of the VCO a high-pass tuning voltage while the feedback path is open including applying a first control voltage to generate a first frequency at the output of the VCO and applying a second control voltage to generate a second frequency at the output of the VCO, the first circuit element being different from the second circuit element, a gain of the VCO being independent of the low-pass tuning voltage if an output frequency of the PLL approximates a final frequency of the PLL.