Clock circuits, components, systems and signal processing methods enabling digital communication are described. A phase locked loop device derives an output signal locked to a first reference clock signal in a feedback loop. A common phase detector is employed to obtain phase differences between a copy of the output signal and a second reference clock signal. The phase differences are employed in an integral phase control loop within the feedback loop to lock the phase locked loop device to the center frequency of the second reference signal. The phase differences are also employed in a proportional phase control loop within the feedback loop to reduce the effect of imperfect component operation. Cascading the integral and proportional phase control within the feedback loop enables an amount of phase error to be filtered out from the output signal.

Clock circuits, components, systems and signal processing methods enabling digital communication are described. A phase locked loop device derives an output signal locked to a first reference clock signal in a feedback loop. A common phase detector is employed to obtain phase differences between a copy of the output signal and a second reference clock signal. The phase differences are employed in an integral phase control loop within the feedback loop to lock the phase locked loop device to the center frequency of the second reference signal. The phase differences are also employed in a proportional phase control loop within the feedback loop to reduce the effect of imperfect component operation. Cascading the integral and proportional phase control within the feedback loop enables an amount of phase error to be filtered out from the output signal.

A method for determining phase continuity of a local oscillator signal generated using a frequency divider is provided. The method includes determining at least one sample of the local oscillator signal. Further, the method includes determining information on the phase continuity using the at least one sample.

A method for determining phase continuity of a local oscillator signal generated using a frequency divider is provided. The method includes determining at least one sample of the local oscillator signal. Further, the method includes determining information on the phase continuity using the at least one sample.

An electronic circuit including: a differential multiplier circuit with a first differential input and a second differential input and a differential output; and a phase locked loop (PLL) circuit including: (1) a balanced differential mixer circuit with a first differential input electrically connected to the differential output of the differential multiplier circuit, a second differential input, and an output; (2) a loop filter having an output and an input electrically connected to the output of the balanced differential mixer circuit; and (3) a voltage controlled oscillator (VCO) circuit having an input electrically connected to the output of the loop filter and with an output electrically feeding back to the second differential input of the balanced differential mixer circuit.

An electronic circuit including: a differential multiplier circuit with a first differential input and a second differential input and a differential output; and a phase locked loop (PLL) circuit including: (1) a balanced differential mixer circuit with a first differential input electrically connected to the differential output of the differential multiplier circuit, a second differential input, and an output; (2) a loop filter having an output and an input electrically connected to the output of the balanced differential mixer circuit; and (3) a voltage controlled oscillator (VCO) circuit having an input electrically connected to the output of the loop filter and with an output electrically feeding back to the second differential input of the balanced differential mixer circuit.

A frequency synthesizer is provided. The frequency synthesizer includes a jitter-cleaning phase-locked loop, a fractional phase-locked loop, a mixer, and a radio-frequency phase-locked loop. The jitter-cleaning phase-locked loop receives a reference clock and a mixed signal, and suppresses a jitter of the reference clock to generate a first oscillating signal based on the reference clock and the mixed signal. The fractional phase-locked loop receives the reference clock and generates a second oscillating signal based on the reference clock. The mixer mixes the first oscillating signal and the second oscillating signal to generate the mixed signal. The radio-frequency phase-locked loop receives the first oscillating signal and generates an output signal based on the first oscillating signal.

Conventional signal sources each have a disadvantage that the noise in a control voltage of a VCO increases, thereby deteriorating the phase noise of an output signal of the signal source.

A signal source of the present invention includes: a reference signal source for outputting a reference signal; a phase frequency comparator for detecting a phase difference between the reference signal and an oscillation signal and outputting a signal corresponding to the phase difference; a filter for filtering the signal output by the phase frequency comparator; an oscillator for outputting the oscillation signal depending on the signal filtered by the filter; and an S/H circuit for receiving a clock signal for controlling a phase of the oscillation signal by controlling sampling operation and holding operation, sampling at least one of the oscillation signal and the reference signal in synchronization with the clock signal, and outputting at least one of the sampled reference signal and the sampled oscillation signal to the phase frequency comparator, the S/H circuit disposed between the oscillator and the phase frequency comparator or between the reference signal source and the phase frequency comparator.

A moving object detection circuit for detecting movement information of a measured object. The moving object detection circuit includes a mixing circuit, an analog-to-digital conversion circuit, a mixing unit, and a distance detecting unit. The mixing circuit mixed the RF carrier signal and a first analog signal to generate a second analog signal. The first analog signal is generated by a signal reflected from the measured object. The analog-to-digital conversion circuit coupled to the mixing circuit for generating a digital signal according to the second analog signal. The mixing unit mixed an IF signal and a first/second IF carrier signal to generate a first/second signal. The distance detecting unit generated a detection result according to the first signal and the second signal. The detection result is corresponding to a distance between the measured object and the moving object detection circuit.

A moving object detection circuit for detecting movement information of a measured object. The moving object detection circuit includes a mixing circuit, an analog-to-digital conversion circuit, a mixing unit, and a distance detecting unit. The mixing circuit mixed the RF carrier signal and a first analog signal to generate a second analog signal. The first analog signal is generated by a signal reflected from the measured object. The analog-to-digital conversion circuit coupled to the mixing circuit for generating a digital signal according to the second analog signal. The mixing unit mixed an IF signal and a first/second IF carrier signal to generate a first/second signal. The distance detecting unit generated a detection result according to the first signal and the second signal. The detection result is corresponding to a distance between the measured object and the moving object detection circuit.