A method of compensating for integral nonlinear interpolation (INL) distortion in a clock synthesizer driven by a system clock running at a frequency f.sub.sys, involves introducing a selected nominal analog delay I*dt with an actual delay of I*dt+ at the output of the a first path with a digital controlled oscillator (DCO) and a digital-to-time converter (DTC) and a nominal digital delay I*D with an actual delay of I*D+ at the input of a second path with a DCO and a DTC that offsets the actual analog delay in the first path, adjusting the contents x(k) of a compensation module in the second path to align the output pulses of the first and second paths for different values of k, where k represents an interpolation point, iteratively repeating the two preceding steps for all N values of I, and averaging the contents x(k) of the compensation module to derive the compensation values to be applied to a one of the DTCs to correct for INL distortion.

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.

A receiver for reducing a distortion component within a baseband receive signal is provided. The baseband receive signal is derived from a radio frequency signal. The receiver includes a signal generation unit configured to generate a local oscillator signal. The local oscillator signal comprises a first signal component having a first frequency related to a desired signal component of the radio frequency signal, and a second signal component having a second frequency related to a frequency of an interfering signal. The receiver further includes a mixer coupled to the signal generation unit. The mixer is configured to receive the local oscillator signal, wherein the mixer receives the local oscillator signal with the interfering signal.

A stacked synthesizer for wide local oscillator (LO) generation using a dynamic divider. The phase locked loop can include a plurality of voltage controlled oscillators (VCOs), and a selector that can be configured to select an output of one of the plurality of VCOs. The selected output of one of the plurality of VCOs can be provided to an on-chip dynamic divider and to an off-chip dynamic divider for LO sharing. The dynamic dividers can be configured to generate synthesizer outputs based on a multiplication of the selected output of one of the plurality of VCOs by a factor (1+1/M), where M is a variable number.

A stacked synthesizer for wide local oscillator (LO) generation using a dynamic divider. The phase locked loop can include a plurality of voltage controlled oscillators (VCOs), and a selector that can be configured to select an output of one of the plurality of VCOs. The selected output of one of the plurality of VCOs can be provided to an on-chip dynamic divider and to an off-chip dynamic divider for LO sharing. The dynamic dividers can be configured to generate synthesizer outputs based on a multiplication of the selected output of one of the plurality of VCOs by a factor (1+1/M), where M is a variable number.

A stacked synthesizer for wide local oscillator (LO) generation using a dynamic divider. The phase locked loop can include a plurality of voltage controlled oscillators (VCOs), and a selector that can be configured to select an output of one of the plurality of VCOs. The selected output of one of the plurality of VCOs can be provided to an on-chip dynamic divider and to an off-chip dynamic divider for LO sharing. The dynamic dividers can be configured to generate synthesizer outputs based on a multiplication of the selected output of one of the plurality of VCOs by a factor (1+1/M), where M is a variable number.

A Phase-Locked Loop (PLL) has a multi-curve voltage-controlled oscillator (VCO) with a curve-select input that adjusts the capacitance within the VCO and thus the VCO gain. A calibration unit generates a curve-select value to the VCO. Coarse calibration selects a Center Curve CC value using binary search of the curve-select bits. During fine calibration, the number of pulses of the VCO output are counted and stored for all curves in a target window around the center curve. The stored pulse counts are compared to an ideal pulse count for a specified frequency, and the curve-select value for the closest-matching pulse count is applied to the VCO. The target window is much smaller than all possible curves, so calibration is performed only on a few curves, reducing calibration time. A switch before the VCO opens the loop for faster open-loop calibration. Pulses are counted digitally without expensive analog comparators.

A system for reference clock frequency correction is described. The system comprises a compensation module configured to (i) receive, as input, an oscillator signal and one or more control signals, (ii) generate a compensation signal based on the oscillator signal and the one or more control signals, wherein the generated compensation signal is a discretized sinusoidal signal having a controllable frequency, and (iii) output the generated compensation signal. The system further comprises a mixer block configured to (i) receive, as input, the generated compensation signal and the oscillator signal, and (ii) generate an output clock signal by mixing the generated compensation signal with the oscillator signal. A soft-switching method to reduce the effect of quantization noise is further described.

A system for reference clock frequency correction is described. The system comprises a compensation module configured to (i) receive, as input, an oscillator signal and one or more control signals, (ii) generate a compensation signal based on the oscillator signal and the one or more control signals, wherein the generated compensation signal is a discretized sinusoidal signal having a controllable frequency, and (iii) output the generated compensation signal. The system further comprises a mixer block configured to (i) receive, as input, the generated compensation signal and the oscillator signal, and (ii) generate an output clock signal by mixing the generated compensation signal with the oscillator signal. A soft-switching method to reduce the effect of quantization noise is further described.

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.