6results about "Heterodyning/beat-frequency comparison" patented technology

By using a detector and voltmeter that do not require high-speed trigger operation, the present invention provides a phase characteristic measurement device that avoids the need for large-scale equipment used for phase measurement and enables relatively inexpensive phase measurement. [Solution] The system includes a first detector 11 that receives and detects three patterns of three-tone signals: a first three-tone signal obtained by combining three waves with angular frequencies ω1, ω2, and ω3 (where ω2-ω1=ω3-ω2=Δω), a second three-tone signal in which each tone has a phase offset, and a third three-tone signal having a different phase offset from the second three-tone signal; a BPF 12 that passes only the beat component of the signal output from the first detector, where the angular frequency difference Δω is between adjacent waves of the three-tone signals; a second detector 13 that detects the power of the beat component that has passed through the BPF 12; a voltmeter 14 that measures the voltage of the signal output from the second detector; and a phase calculator 15 that calculates the phase based on the measured voltage values ​​of the three patterns.

This application discloses a signal detection system, comprising: a frequency estimation device and a signal detection device; the output terminal of the frequency estimation device is connected to the input terminal of the signal detection device. The system can generate a chaotic photoelectric oscillator radio frequency signal by estimating the frequency of the incident signal and the optical carrier signal based on environmental conditions. Then, the chaotic photoelectric oscillator radio frequency signal is used to detect the target signal (i.e., a weak microwave photon signal). Therefore, the system can achieve the reception of weak signals within a large dynamic bandwidth, overcoming the shortcomings of traditional signal detection methods, such as narrow operating bandwidth and low detection sensitivity.

A first detector that receives and detects 3-tone signals of three patterns of a first 3-tone signal obtained by combining three waves of angular frequencies ω1, ω2, and ω3 (here, ω2−ω1=ω3−ω2=Δω is established), a second 3-tone signal in which each tone has a phase offset, and a third 3-tone signal having a phase offset different from the phase offset of the second 3-tone signal, a BPF that allows only a beat component of an angular frequency difference Δω between adjacent waves of the 3-tone signals among signals output from the first detector to pass, a second detector that detects power of the beat component that has passed through the BPF, a voltmeter that measures a voltage of a signal output from the second detector, and a phase calculator that calculates a phase based on the measured voltage values of the three patterns.

This invention provides a frequency following sampling and dual-frequency calibration method and system for synchronization inspection devices, relating to the field of power system signal processing technology. The method includes: calculating the frequency of the rising edge of the system-side voltage signal and the rising edge of the voltage signal to be paralleled on the target side to generate a stable frequency on the system side and a stable frequency on the target side; determining the validity and balance of the stable frequencies on the system side and the target side, using a frequency following strategy to determine the effective following frequency and outputting the frequency balance result; dynamically selecting the signal sampling mode by calling a timer reconfiguration function, synchronously sampling the system-side voltage signal and the voltage signal to be paralleled on the target side, and performing a Fourier transform based on the frequency balance result to generate the voltage amplitude on the system side and the voltage amplitude on the target side; and calibrating and correcting the voltage amplitude on the system side and the voltage amplitude on the target side using a linear interpolation algorithm to generate a standard voltage amplitude on the system side and the standard voltage amplitude on the target side, thereby eliminating spectral leakage and improving the measurement accuracy of the voltage amplitude.

A non-contact method is presented for measuring vibration on a surface of an object. The method includes: projecting light from one or more light sources towards an area of interest on a surface of an object; detecting the light diffusely reflected by the surface of the object using one or more detectors; determining a change in position of the reflected light detected by the detector over time; for the at least one point on the surface of the object, calculating a series of measurements of vertical displacement of the surface over a period of time from the change in position of the reflected light and using triangulation; and determining frequency of a disturbance of the surface at the at least one point on the surface and an amplitude of the disturbance using the series of measurements of vertical displacement.

The invention provides a device response measurement system and method. According to the device response measurement system and method, outputs of pulse light sources with two different repetition frequencies are input into a photoelectric conversion device and an electro-optical frequency mixing device respectively, and electric signals generated by the photoelectric conversion device are transmitted through a radio frequency channel and then are loaded to the electro-optical frequency mixing device. Through multi-heterodyne beat frequency sampling, the sampling difficulty of a broadband signal is obviously reduced, so that response measurement of a broadband device is realized. The method does not need a complex microwave up-down conversion system, and has the advantages of low system complexity, low cost and wide coverage frequency range.