Abstract: Provided is a phase-lock loop gear shifter that includes: an input for receiving a loop gain that is dynamically controllable; an input for receiving a phase-error signal; a subtractor configured to provide a gain difference between the loop gain input at a second time and the loop gain input at a first time, the first time being earlier than the second time; a module that determines a characteristic phase-error value based on the phase-error signal; and a multiplier that multiplies the gain difference by the characteristic phase-error value to provide a control-signal correction value.

Abstract: A method of operation for a dual mode Phase-Locked Loop (PLL) for phase coherent application includes selecting one of a non-coherent mode and a coherent mode. The non-coherent mode includes controlling a Voltage Controlled Oscillator (VCO) with a first error voltage determined by a first Low Pass Filter (LPF), the first LPF configured to filter a first output of a phase detector, the phase detector configured to determine a phase difference between a reference frequency and a feedback signal derived from a VCO frequency generated by the VCO. The coherent mode includes controlling the VCO with the first error voltage and a second error voltage determined by a second LPF of a Proportional and Integral Controller (PIC) configured to filter the first output of the phase detector and by a time variant proportional gain configured to modify a second output of the second LPF.

Abstract: A transmit apparatus comprising a scaler arranged to scale a frequency deviation signal associated with a frequency shift keying signal (FSK) by a scale factor and a limiter arranged to limit frequency deviations of the scaled frequency deviation signal after a filtering. A power spectral density, phase trajectory, and frequency deviation of an FSK signal based on the limited scaled frequency deviation tracks similar criteria of a minimum phase shift keying (MSK) signal.

Abstract: A transmit apparatus comprising a scaler arranged to scale a frequency deviation signal associated with a frequency shift keying signal (FSK) by a scale factor and a limiter arranged to limit frequency deviations of the scaled frequency deviation signal after a filtering. A power spectral density, phase trajectory, and frequency deviation of an FSK signal based on the limited scaled frequency deviation tracks similar criteria of a minimum phase shift keying (MSK) signal.

Abstract: Provided is a phase-lock loop that includes: an oscillator having an input for receiving a control signal and an output for providing an output signal having a frequency based on the control signal; a phase detector having a first input for receiving a reference signal, a second input coupled to the output of the oscillator for receiving a feedback signal, and an output for providing a phase-error signal that is indicative of a phase difference between the reference signal and the feedback signal; and a loop filter having a first input coupled to the output of the phase detector, a second input for receiving a proportional-phase-compensation value, and an output for providing the control signal to the oscillator. The control signal comprises a proportional component which is a combination of the phase-error signal and the proportional-phase-compensation value.

Abstract: Provided is a phase-lock loop gear shifter that includes: an input for receiving a loop gain that is dynamically controllable; an input for receiving a phase-error signal; a subtractor configured to provide a gain difference between the loop gain input at a second time and the loop gain input at a first time, the first time being earlier than the second time; a module that determines a characteristic phase-error value based on the phase-error signal; and a multiplier that multiplies the gain difference by the characteristic phase-error value to provide a control-signal correction value.

Abstract: An analog PLL comprising: a VCO configured to provide a PLL output signal; a phase detector (PD) configured to receive a feedback signal from the VCO and a reference signal and wherein the PD provides a PD signal to a low pass filter (LPF), the LPF configured to filter of the PD signal and provide the filtered signal as a tuning voltage for the VCO; and a tracking loop configured to receive the tuning voltage and comprising at least a tracking loop comparator configured to provide a comparator output voltage based on a difference between the tuning voltage and a target voltage, wherein an output of the tracking loop provides a tracking voltage based on the comparator output voltage and wherein the frequency of the PLL output voltage is based on the tuning voltage and the tracking voltage.

Abstract: A duty cycle correction circuit (DCCC) for a multi-modulus frequency divider, the DCCC comprising: a corrector chain comprising a plurality of flip-flops each configured to receive one of the internal signals; and at least one delay selection logic element, each configured to receive an output signal from different ones of the flip-flops and the output of each delay selection logic element is based on the received output signal and the division factor; the DCCC is configured such that: a first state change in its output signal is defined by a transition to a first logic state of one of the internal signals; and a second state change in its output signal is based on a transition to a second logic state of one of the internal signals after a delay period, wherein the duty cycle of the output signal is based on the delay period.

Abstract: An analog PLL comprising: a VCO configured to provide a PLL output signal; a phase detector (PD) configured to receive a feedback signal from the VCO and a reference signal and wherein the PD provides a PD signal to a low pass filter (LPF), the LPF configured to filter of the PD signal and provide the filtered signal as a tuning voltage for the VCO; and a tracking loop configured to receive the tuning voltage and comprising at least a tracking loop comparator configured to provide a comparator output voltage based on a difference between the tuning voltage and a target voltage, wherein an output of the tracking loop provides a tracking voltage based on the comparator output voltage and wherein the frequency of the PLL output voltage is based on the tuning voltage and the tracking voltage.