Performance indicator for phase locked loops

Performance indicator circuitry adapted to characterize performance of a phase locked loop (PLL) comprising an oscillator, a high pass path, and a low pass path comprising loop filter circuitry, wherein the PLL is in a phase path of a phase modulator, wherein the loop filter circuitry comprises gain circuitry that outputs an amplified signal, a low pass filter that outputs a filtered signal, and integrator circuitry that outputs an integrated signal, the performance indicator circuitry comprising:

• first input circuitry comprising a multiplexer that selects one of the amplified signal, the low pass signal, or the integrated signal;
• and
• parameter calculation circuitry configured to:
• compute a value for a performance indicator based on the selected signal;
• and
• control an aspect of operation of the PLL based on the value.

Performance indicator circuitry adapted to characterize performance of a phase locked loop (PLL) comprising an oscillator, a high pass path, and a low pass path comprising loop filter circuitry, wherein the PLL is in a phase path of a phase modulator, the performance indicator circuitry comprising:

• first input circuitry configured to input a signal from the loop filter circuitry;
• parameter calculation circuitry configured to compute a value of a statistical characterization of the loop filter signal over time and control an aspect of operation of the PLL based on the value;
• and
• trigger circuitry configured to detect a trigger signal, and in response, cause the parameter calculation unit to compute the statistical characterization over a predetermined time period.

A phase modulator configured to process a frequency modulation signal to generate a phase modulated radio frequency (RF) signal for recombination with an amplitude modulation signal to generate a phase and amplitude modulated RF signal, the phase modulator comprising:

• alignment circuitry configured to process the frequency modulation signal to produce a low pass signal and a high pass signal;
• a phase locked loop, comprising:
• an oscillator configured to generate the phase modulated RF signal based on a control signal;
• a loop filter comprising a series of circuitry, wherein each circuitry in the loop filter is configured to output a respective unique loop filter signal;
• and
• summation circuitry configured to add the high pass signal to an output of the loop filter to generate the control signal;
• and
• performance indicator circuitry comprising:
• first input circuitry configured to input a selected loop filter signal;
• parameter calculation circuitry configured to compute a value for a performance indicator based at least on the loop filter signal;
• and
• second input circuitry configured to input the frequency modulation signal, comprising:
• a reference filter that inputs the frequency modulation signal and outputs a filtered frequency modulation signal;
• and
• a multiplexer that selects one of the filtered frequency modulation signal or the frequency modulation signal and inputs the selected signal to the parameter calculation circuitry, and
• wherein the parameter calculation circuitry is configured to calculate the value based on a correlation between the loop filter signal and the frequency modulation signal.

A phase modulator configured to process a frequency modulation signal to generate a phase modulated radio frequency (RF) signal for recombination with an amplitude modulation signal to generate a phase and amplitude modulated RF signal, the phase modulator comprising:

• alignment circuitry configured to process the frequency modulation signal to produce a low pass signal and a high pass signal;
• a phase locked loop, comprising:
• an oscillator configured to generate the phase modulated RF signal based on a control signal;
• a loop filter comprising gain circuitry that outputs an amplified signal, a low pass filter that outputs a filtered signal, and integrator circuitry that outputs an integrated signal;
• and
• summation circuitry configured to add the high pass signal to the output of the loop filter to generate the control signal;
• and
• performance indicator circuitry comprising:
• input circuitry comprising a multiplexer that selects one of the amplified signal, the low pass signal, or the integrated signal;
• and
• parameter calculation circuitry configured to compute a value for a performance indicator based at least on the selected signal.

A phase modulator configured to process a frequency modulation signal to generate a phase modulated radio frequency (RF) signal for recombination with an amplitude modulation signal to generate a phase and amplitude modulated RF signal, the phase modulator comprising:

• alignment circuitry configured to process the frequency modulation signal to produce a low pass signal and a high pass signal;
• a phase locked loop, comprising:
• an oscillator configured to generate the phase modulated RF signal based on a control signal;
• a loop filter comprising a series of circuitry, wherein each circuitry in the loop filter is configured to output a respective unique loop filter signal;
• and
• summation circuitry configured to add the high pass signal to the output of the loop filter circuitry to generate the control signal;
• and
• performance indicator circuitry comprising:
• input circuitry configured to input a selected loop filter signal;
• and
• parameter calculation circuitry configured to compute a statistical characterization of the loop filter signal over time;
• and
• trigger circuitry configured to detect a trigger signal, and in response, cause the parameter calculation unit to compute the statistical characterization.

A method for use with a phase locked loop comprising an oscillator configured to generate a phase modulated signal based on a control signal and a loop filter comprising a series of circuitry, wherein each circuitry in the loop filter is configured to output a respective unique loop filter signal, the method comprising:

• inputting a loop filter signal from the loop filter;
• inputting a frequency modulation signal;
• filtering the frequency modulation signal;
• computing a value for a performance indicator based on a correlation between the loop filter signal and the filtered frequency modulation signal;
• and
• characterizing performance of the PLL based on the value.

A method for use with a phase locked loop comprising an oscillator configured to generate a phase modulated signal based on a control signal and a loop filter comprising a gain circuitry that outputs an amplified signal, a low pass filter that outputs a filtered signal, and integrator circuitry that outputs an integrated signal, the method comprising:

• selecting one of the amplified signal, the low pass signal, or the integrated signal;
• inputting the selected signal;
• and
• computing a value for a performance indicator based on the selected signal;
• and
• characterizing performance of the PLL based on the value.