Abstract:
A method for measuring channel-to-channel skew or phase difference in an electronic system of the type having a plurality of input channels which are sampled by sampling pulses having a frequency fo and a period Po. The sampling pulses at each input channel are first mixed with a reference signal having a frequency fr and a period Pr that differ from the frequency and period of the sampling pulses. The mixing produces a beat signal at each input channel. A quantity termed ''effective measurement interval'' which is equal to the difference of the periods of the sampling pulses, Po, and the reference signal, Pr, is computed. A quantity termed ''apparent skew'' which is equal to the number of periods Po of the sampling pulses which represents the skew or phase difference between the beat signals is also determined. Finally, skew of phase difference of the sampling pulses is computed by multiplying the ''effective measurement interval'' by the ''apparent skew''.
Abstract:
A phase detector providing linear phase information from -180° to +180° is disclosed. The phase detector comprises frequency divider and phase shifter and a mixer circuit, frequency divider and phase shifter has an output port connected to an input port of the mixer circuit.
Abstract:
A phase digitizer and method with error compensation is provided that utilizes recordings from a digitally generated phase reference to measure the relative time between events, such as, for example, between the input zero crossing and sample pulse events. The digital reference has a constant frequency which is equal to the desired signal frequency, and thus the phase of the reference can be used to measure the time between events. Consequently, by using the existing digitally generated phase reference, the hardware "costs" associated with implementing the prior phase digitizer error compensation approaches can be significantly reduced and/or eliminated.
Abstract:
Proposed is a device for the determination of the phase difference between a first and a second digital input signal (S1, S2). A first embodiment calls for the generation of a clock signal (CLOCK) which is fed as the first (counter) signal (18) to a first counter (16) which is reset by the occurrence of a predetermined flank (31) of the first signal (S1). This embodiment permits phase measurements to be made at a high repetition rate within the range from 0 to 360 DEG . In a second and third embodiment, which are preferably implemented together and may optionally be combined with the first embodiment, a second and third (switch) signal (FWD, BACK) are generated from the digital input signals (S1, S2) and used to control a count-down/count-up counter (20). The second and third embodiments are suitable for the determination of differences in phase equal to multiples of 360 DEG between the two input signals (S1, S2). The device proposed is particularly suitable for the measurement of the phase differences which occur between the output signals of two photodetectors fitted in a heterodyne interferometer.
Abstract:
A wireless communication transmitter is configured to determine transmitter phase shift, and correspondingly includes a derivation circuit, one or more slope polarity tracking circuits, and a phase shift computation circuit. The derivation circuit derives a reference signal from a signal input to the transmitter and a feedback signal from the transmit signal corresponding to that input signal. So derived, differences in the reference and feedback signals reveal the effect the transmitter has on the transmit signal. Accordingly, the transmitter focuses on differences in the polarities of the reference signal's slope and the feedback signal's slope to determine the effect the transmitter has on the phase of the transmit signal. That is, the slope polarity tracking circuits track the slope polarities of the reference and feedback signals, while the phase shift computation circuit computes the transmitter phase shift as a function of differences in those tracked slope polarities.
Abstract:
The invention concerns a digital phase detector for the determination of phase shifts between a comparison clock signal (VT) and a reference clock signal (RT). First means (STA, STO) generate start and stop signals from the pulses of the reference and comparison clock signals (RT, VT). A counter (ZG, Z) counts the pulses of a higher-frequency counter clock signal (ZT) in the time slot between a start signal and the subsequent stop signal. The count registered by the counter (ZG, Z) is a measure of the phase shift. Digital phase detectors of this kind exhibit quantization errors. The use of a sign information (VZ) derived from the comparison clock signal, which leads or lags the reference clock signal, and means (MP) which add a constant to the counter count enables the effects of the quantization error to be significantly reduced. The phase detector proposed makes it possible to design phase-control loops giving precise clock-signal adjustment since it provides a control signal even when the phase shift between the comparison and reference clock signals is very small.
Abstract:
A magnetic flowmeter comprises a first electric circuit (6) providing a first alternating electrical signal generated mostly by an electromagnetic interaction between an alternating magnetic field and the velocity of an electrically conductive fluid moving in a direction transverse to the alternating magnetic field, and a second electric circuit (10 or 36) providing a second alternating electrical signal generated moslty by an electromagnetic induction between the alternating magnetic field and an inductive circuit element (37) included in the second electric circuit, wherein the velocity of the electrically conductive fluid is determined as a function of a phase angle difference between the first and second alternating electrical signals.
Abstract:
An all-digital delay measurement circuit (DMC) constructed on an integrated circuit (IC) die characterizes clocking circuits such as full phase rotation interpolators, also constructed on the IC die. The on-die all-digital DMC produces a digital output value proportional to the relative delay between two clocks, normalized to the clock period of the two clocks.