8 results about "Length wave" patented technology

A length calculation unit calculates, based on a transmission time required for an optical signal transmitted from a first optical transmission apparatus to a second optical transmission apparatus through an optical transmission line to be transmitted through the optical transmission line, a length of the optical transmission line. A wavelength dispersion calculation unit calculates a wavelength dispersion per unit length of the optical transmission line based on a wavelength dispersion of the optical signal received by the second optical transmission apparatus and the length of the optical transmission line. A type determination unit determines a type of the optical transmission line based on information indicating a correspondence relationship between a value of the wavelength dispersion per unit length and the type of the optical transmission line and the calculated wavelength dispersion per unit length of the optical transmission line.

Beam steering devices such as optical phased arrays (OPAs) are key components in applications of solid-state LIDAR and wireless communication. Conventional single-layer OPAs suffer from significant energy loss due to substrate leakage from the down-coupling of grating coupler structures. In this disclosure, we have investigated a structure based on a multi-layer Si3N4 / SiO2 platform that can form a 3D OPA to efficiently emit light from the edge of the device, end-fire the 2D converging out-coupled beam to air. Numerically demonstrated is the high efficiency and wide horizontal beam steering, also discussed are the effects of vertical crosstalk, delay length, number of waveguide layers, and manufacturing feasibility.

This application discloses a method, system, and medium for locating faults at both ends of a transmission line based on the temperature variation characteristics of the transmission line. It belongs to the field of fault location technology for power system transmission lines. The method includes: acquiring the real-time temperature of the transmission line, fixed design parameters, and the arrival time of the fault traveling wave at both ends; determining the corrected line length based on the fixed design parameters and real-time temperature, according to the thermal expansion and contraction relationship of the conductor; determining the inductance and capacitance per unit length based on the real-time temperature and transmission line theory, and determining the corrected traveling wave velocity based on the relationship between wave velocity and distributed parameters; and determining the distance to the fault point based on the principle of two-end traveling wave location, according to the corrected line length, wave velocity, and arrival time of the traveling wave. By implementing this application, the problem of mismatch between the location parameters and the actual physical state caused by parameter fixation in the traditional two-end traveling wave location method can be solved, thus improving the accuracy of fault location.

The invention provides an arbitrary-length waveform construction method, system and device based on a vector signal generator and a storage medium, and belongs to the technical field of communication. Comprising the following steps that S1, the data length L and the data bit width W1 of an input original waveform file are determined, and the original waveform file has any waveform length; s2, determining a fixed burst operation length N of a read-write DDR chip adopted by the vector signal generator and a fixed data bit width W2 of the DDR chip; s3, a burst operation multiple factor K is determined, and the burst operation multiple factor K is the ratio of the burst operation bit width to the original waveform file data bit width; s4, determining a repetition factor M according to the data length L of the original waveform file and the burst operation multiple factor K; and S5, adaptively reconstructing new waveform data according to the repetition factor M and the original waveform file. According to the method, loading of the original waveform file with any waveform length can be achieved, and the method is simple and easy to implement.

The present invention relates to the field of spectral imaging, and provides a full-spectrum imaging detection system, including a primary mirror, a secondary mirror, a field of view separator, a visible short-wave rear optical path system, and a medium- and long-wave rear optical path system; the visible short-wave rear optical path system includes a first deflection mirror, a second deflection mirror, a third reflector, a fourth reflector, and a fifth reflector; light sequentially passes through the primary mirror, the secondary mirror, the first deflection mirror, the second deflection mirror, the third reflector, the fourth reflector, and the fifth reflector to perform visible short-wave band imaging; the medium- and long-wave rear optical path system includes a third deflection mirror, a fourth deflection mirror, a sixth reflector, a seventh reflector, and an eighth reflector; light sequentially passes through the primary mirror, the secondary mirror, the third deflection mirror, the fourth deflection mirror, the sixth reflector, the seventh reflector, and the eighth reflector to perform medium- and long-wave band imaging. The invention is used to solve the defect that the satellite-borne large-aperture ground detection camera in the prior art can often only perform imaging of a single spectrum and cannot meet the requirement of synchronous acquisition of high-resolution full-spectrum information. The scheme of the present application can complete imaging detection of the full spectrum on a single payload.

To provide an optical interference circuit which is applied to a system for transmitting and frequency-converting frequency reference light and can transmit each of a plurality of frequencies of the frequency reference light while maintaining high frequency accuracy.SOLUTION: An optical interference circuit according to the present invention includes a waveguide circuit unit in which an optical waveguide is formed on a substrate, and a frequency conversion unit that converts a frequency of frequency reference light, in which the waveguide circuit unit further includes a reproduction reference light input port, a frequency reference light input / output port, a transmission path fiber input / output port, a first coupler, a frequency selective reflection unit, a frequency synchronization detection circuit, a first detection light output port, a transmission path length fluctuation detection circuit, and a second detection light output port, and the frequency synchronization detection circuit further includes one second coupler. The transmission line length fluctuation detection circuit further includes one third coupler and one fourth coupler connected to the third coupler.SELECTED DRAWING: Figure 4

The present invention relates to a grading method for ultrasonic transducers used for gas metering, belonging to the field of ultrasonic transducer detection technology. First, based on the transducer admittance frequency response obtained by a network analyzer, screening is performed to select transducers with similar admittance parameters and resonant frequencies; according to five grading selection conditions set by a host computer, namely, a signal gain value G, a sampling time length T, a limited range of antinode values, a number of equal divisions m of the sampling time length T, and a corresponding normalized envelope amplitude difference limit of a transducer receiving signal, amplification, filtering and sampling of a received signal within the sampling time length T, ADC, curve fitting of a received signal peak, storage and calculation of received signal envelope amplitude, antinode value, normalized envelope amplitude and normalized envelope amplitude difference, etc., the similarity of the waveform envelope of the transducer receiving signal is judged, and automatic grading is realized. The present invention can ensure that the transducer has better consistency within the used temperature range.

The invention discloses a medium-long wave infrared spectrum imaging data calibration device and method, and relates to the technical field of spectrum testing. The device provided by the invention comprises a black body, a cold screen, infrared spectrum imaging equipment and a data processing unit, the black body is arranged at an entrance pupil of the infrared spectrum imaging equipment; the cold screen is movably arranged in the infrared spectrum imaging equipment, and after the cold screen is moved, the cold screen is located at an entrance pupil of the infrared spectrum imaging equipment; and the infrared spectrum imaging equipment is electrically connected with the data processing unit. In the medium-long wave infrared spectral imaging data calibration process, the data processing unit adopts complex Fourier transform, frequency domain information can be converted into spatial domain information, the accuracy and reliability of data processing are improved, and accurate calibration of the infrared spectral imaging data is realized based on the acquired interference pattern and the data radiation calibration result. In addition, by arranging the cold screen, the influence of air interference in the spectral imaging equipment can be effectively reduced, and the precision of infrared spectral imaging data is improved.