Abstract: Aspects of a digital phase-lock loop (DPLL) with an adjustable delay between an output clock and a reference clock in accordance with phase noise compensation are generally described herein. An apparatus may include processing circuitry configured to, in a first mode, identify a delay element of a plurality of delay elements based on an associated delay value, and set an initial phase difference value to a phase difference value associated with the identified delay element. The processor circuitry may be further configured to, in a second mode, in a second mode, initialize the DPLL using the initial phase difference value, determine a phase error between a reference clock and a feedback clock based on the initial phase difference value, adjust an output clock signal based on the phase error.

Abstract: A phase locked loop (PLL) system for mitigating non-linear phase errors stemming from time-variant integral non-linearity of the LO feedback phase quantizer (TDC) is disclosed. The system includes a phase modulation circuit which is configured to generate a plurality of phase shifts for a reference signal; select a phase shift of the plurality of phase shifts and introduce the selected phase shift into the reference signal, thereby modulating the phase difference between the feedback and the reference signal. Alternatively, the above phase modulation can be applied on the feedback signal path, attaining equivalent results. TDC is configured to quantize the phase of the LO feedback signal relative to the shifted reference signal to generate a phase detection signal, effectively modulating the non-linearity contributed error away from the LO center frequency.

Abstract: Aspects of a digital phase-lock loop (DPLL) with an adjustable delay between an output clock and a reference clock in accordance with phase noise compensation are generally described herein. An apparatus may include processing circuitry configured to, in a first mode, identify a delay element of a plurality of delay elements based on an associated delay value, and set an initial phase difference value to a phase difference value associated with the identified delay element. The processor circuitry may be further configured to, in a second mode, in a second mode, initialize the DPLL using the initial phase difference value, determine a phase error between a reference clock and a feedback clock based on the initial phase difference value, adjust an output clock signal based on the phase error.

Abstract: A time-to-digital converter is provided. The time-to-digital converter includes a delay circuit configured to iteratively delay a reference signal for generating a plurality of delayed reference signals. Further, the time-to-digital converter includes a plurality of sample circuits each configured to sample an oscillation signal based on one of the plurality of delayed reference signals. The time-to-digital converter additionally includes a control circuit configured to de-activate at least one of the plurality of sample circuits based on a predicted value of the phase of the oscillation signal.

Abstract: Systems, methods, and circuitries are disclosed for controlling an adaptive time-to-digital converter (TDC) that determines a phase difference between a reference signal and a phase locked loop (PLL) feedback signal. Adaptive TDC circuitry includes a chain of n delay elements each characterized by an incremental delay. Gate circuitry outputs a gated PLL feedback signal while a gating enable signal has an enable value. N sampling elements, each associated with a delay element, are enabled by the reference signal arriving at the input of the associated delay element to store a value of the gated PLL feedback signal. Adaptive gating circuitry is configured to generate the gating enable signal based on the incremental delay and a period of the PLL feedback signal. A supply voltage for the delay elements may be controlled to cause the delay elements to exhibit a desired incremental delay.

Abstract: Embodiments of a reference path circuit and communication device are generally described herein. The reference path circuit may include an injection locked multiplier (ILM) and a group of one or more buffer amplifiers. The ILM may receive a sinusoidal reference signal from a reference oscillator at a reference frequency. The ILM may generate a sinusoidal ILM output signal at an ILM output frequency that is based on an integer multiple of the reference frequency. The integer multiple of the reference frequency may be within a locking range of the ILM that may be based on a resonant frequency of the ILM. The group of one or more buffer amplifiers may generate an output clock signal for input to the frequency synthesizer. The output clock signal may be based on a sign function of the ILM output signal.

Abstract: Systems, methods, and circuitries for synchronizing a first phase locked loop (PLL) with a second PLL are provided. In one example a PLL system includes a first PLL configured to generate a first signal; a second PLL configured to generate a second signal; and phase calculation circuitry. The phase calculation circuitry is configured to calculate a phase of the first signal at a given time; and provide the calculated phase to the second PLL for use by the second PLL in synchronizing a phase of the second with the phase of the first signal.

Abstract: A circuit is configured to reduce a noise component of a measured phase signal. The circuit includes an input for a phase signal of an oscillator and an error signal estimator configured to determine parity information and an estimated error amplitude in the phase signal based on the parity information. The circuit further includes a combiner configured to provide the measured phase signal with the reduced noise component based on a combination of the phase signal and the estimated error amplitude.

Abstract: Systems, methods, and circuitries for synchronizing a first phase locked loop (PLL) with a second PLL are provided. In one example a PLL system includes a first PLL configured to generate a first signal; a second PLL configured to generate a second signal; and phase calculation circuitry. The phase calculation circuitry is configured to calculate a phase of the first signal at a given time; and provide the calculated phase to the second PLL for use by the second PLL in synchronizing a phase of the second with the phase of the first signal.

Abstract: Control circuitry for use in generating a local oscillator (LO) signal is provided. Synthesizer control circuitry is configured to control synthesizer circuity to generate an analog oscillator signal having a first frequency at which phase noise is minimized. DS control circuitry is configured to generate a control word or message to cause DS circuitry to generate a digital DS signal having a desired frequency when the DS circuitry is clocked by the oscillator signal having the first frequency. The desired frequency is proportional to the LO signal frequency. The digital DS signal generated by the DS circuitry is used to generate the LO signal. Thus the first frequency used to clock the DS circuitry is selected to optimize the oscillator rather than having some relationship to the LO frequency. In addition, a single synthesizer may be used in order to simultaneously generate many LO signals.

Abstract: Control circuitry for use in generating a local oscillator (LO) signal is provided. Synthesizer control circuitry is configured to control synthesizer circuitry to generate an analog oscillator signal having a first frequency at which phase noise is minimized. DS control circuitry is configured to generate a control word or message to cause DS circuitry to generate a digital DS signal having a desired frequency when the DS circuitry is clocked by the oscillator signal having the first frequency. The desired frequency is proportional to the LO signal frequency. The digital DS signal generated by the DS circuitry is used to generate the LO signal. Thus the first frequency used to clock the DS circuitry is selected to optimize the oscillator rather than having some relationship to the LO frequency. In addition, a single synthesizer may be used in order to simultaneously generate many LO signals.

Abstract: A digital phase lock loop (DPLL) device or system can operate to analyze and estimate a deterministic jitter in the digital domain, while correcting for it in the analog domain. A reference oscillator can provide an analog reference signal to the DPLL via a reference path. A shaper of the reference path can process the analog reference signal and provide a digital signal to a doubler component that doubles the frequency for a digital reference signal. The doubler component itself can add deterministic jitter to the noise of the digital reference signal it provides to the DPLL. An estimation of the DPLL performs various calibration processes to determine the deterministic jitter in the digital domain and provide an analog bias signal to the signal shaper component to correct for the deterministic jitter, keeping it at around zero.

Abstract: Embodiments of a reference path circuit and communication device are generally described herein. The reference path circuit may include an injection locked multiplier (ILM) and a group of one or more buffer amplifiers. The ILM may receive a sinusoidal reference signal from a reference oscillator at a reference frequency. The ILM may generate a sinusoidal ILM output signal at an ILM output frequency that is based on an integer multiple of the reference frequency. The integer multiple of the reference frequency may be within a locking range of the ILM that may be based on a resonant frequency of the ILM. The group of one or more buffer amplifiers may generate an output clock signal for input to the frequency synthesizer. The output clock signal may be based on a sign function of the ILM output signal.