12results about How to "Reduce phase error" patented technology

The invention relates to the field of atomic interference measurement, in particular to an atomic Raman interferometer based on a flat-topped beam. Comprising two Raman interference subsystems arranged in parallel, each of the two Raman interference subsystems comprises an ultrahigh vacuum cavity and a light path system, and the light path system comprises a flat-topped beam shaping module located on one side of the high vacuum cavity and a Raman light Doppler sensitive configuration module located on the other side of the high vacuum cavity; in the flat-topped beam shaping module, the holographic algorithm principle is adopted, the actual size of atoms in an interference area is combined to determine the size of a target flat-topped beam, the initial complex amplitude is precisely constrained, and a final diffraction phase is obtained through iterative optimization. After the Raman light passes through the diffraction phase, the Raman light is shaped into a flat-topped light beam with a target size and uniform intensity distribution at the ultrahigh vacuum cavity, so that the coherence efficiency under the same interference time is remarkably improved.

The invention discloses a D wave band frequency expansion device system for a channel simulator and a calibration method, the D wave band frequency expansion device system comprises a low-frequency channel simulator, a local oscillator distributor, a D wave band transmitting link, a D wave band receiving link and a D wave band waveguide bi-directional coupler, and the system supports terahertz frequency band spread spectrum and calibration functions of the low-frequency channel simulator. A local oscillator distributor is adopted to ensure phase synchronization of an uplink and a downlink, and receiving and transmitting isolation of the same physical channel is realized through a waveguide bi-directional coupler, so that uplink and downlink full duplex testing of communication equipment is realized. Calibration of the whole system is completed by the low-frequency channel simulator and the frequency expansion device together, and compensation of nonlinearity, amplitude-frequency and local oscillation leakage of D-band signals can be achieved by adopting the calibration method. Compared with the prior art, the device can realize accurate simulation of a D-band full-band channel and full-duplex transceiving performance verification, and provides more reliable technical support for test and verification of high-band wireless communication.

This invention belongs to the technical field of angle detection devices, specifically relating to a high-sensitivity angle detection device based on the tunneling magnetoresistive effect. It includes an upper substrate and a lower substrate, with the upper substrate positioned above the lower substrate and parallel to it, without contact between them. The upper substrate includes a fixed substrate, a square cutout, magnetoresistive power supply wires, a tunneling magnetoresistive element, a magnetoresistive signal transmission line, and a glass substrate. The fixed substrate is positioned above the lower substrate, with a square cutout at its center. This invention utilizes the tunneling magnetoresistive effect for detection, easily achieving full-circle detection by the angle sensor. Furthermore, the phase-shifting circuit combined with the subdivision circuit in the signal processing module improves the measurement resolution, providing a framework for achieving high-precision full-circle angle measurement using other magnetic angle sensors.

The present application relates to servo motor production test technical field, especially relates to a kind of encoder detection method, device and storage medium, the method comprises: establishing the design requirement parameter library stored according to motor model;Connecting motor to be detected and calling corresponding preset design index;Control motor low-speed no-load rotation;Based on the same hardware timer, encoder A / B / Z signal and hall U / V / W signal are synchronously collected, and synchronous timing data is generated;Synchronous timing data is judged effectively;Actual encoder line number, actual electrical phase and actual hall phase are calculated;Actual parameter is compared with preset design index item by item, all satisfy when judging qualified, any item does not satisfy when judging unqualified and recording deviation.The present application can improve servo motor encoder detection efficiency and phase determination accuracy, adapt to multi-model mixed-line production, and realize detection process traceability.

The present invention provides a method for collecting and processing micro-blood flow of coronary arteries based on ultrasound, comprising the following steps: S1, obtaining a demodulated baseband channel data set; S2, obtaining a tissue signal and a blood flow signal; S3, executing a third processing path on the tissue signal, and simultaneously obtaining myocardial motion estimation information and a spectral Doppler image; S4, inputting the myocardial motion estimation information into a first processing path and a second processing path respectively as a feedback mechanism; S5, executing the first processing path on the tissue signal, and obtaining a grayscale tissue image in combination with the myocardial motion estimation information; S6, executing the second processing path on the blood flow signal, and obtaining a power Doppler image and a velocity Doppler image in combination with the myocardial motion estimation information; S7, outputting a grayscale tissue image, a power Doppler image, a velocity Doppler image and a spectral Doppler image as a final image. The present invention can realize high-sensitivity imaging of micro-vessels of coronary arteries without contrast agents.

The present invention discloses an intelligent quantization compression method for raw data of spaceborne SAR, S1: receiving an intermediate frequency radar echo signal, filtering and sampling, and obtaining raw echo data with a bit number of 8 (the first bit is a sign bit); S2: sampling the raw echo data with an M×M block size to obtain a number of block data, storing and calculating the amplitude mean and variance value corresponding to each block data; S3: finding the corresponding compression code value from a preset compression coding table, and compressing the block data according to the compression code value to obtain compressed block data; S4: framing based on the sign bit, the amplitude mean, the variance value and the compressed block data to obtain the compression value. The present invention can improve the quantization compression signal-to-noise ratio of the echo data and reduce the amplitude error and phase error. Through the preset compression coding table and the pre-extraction of the sign bit, the data processing function of any compression ratio such as 8:8 (uncompressed), 8:7, 8:6, 8:5, 8:4, 8:3, etc. can be realized.

The invention relates to a large-bandwidth integrated optical beam splitter based on a sub-wavelength grating and a preparation method of the large-bandwidth integrated optical beam splitter, and belongs to the technical field of integrated photonic devices and semiconductors. The large-bandwidth integrated optical beam splitter comprises a substrate, a first cladding, a waveguide layer, a glass layer and a second cladding, the substrate, the first cladding, the waveguide layer, the glass layer and the second cladding are sequentially arranged from bottom to top, the waveguide layer is arranged in the glass layer, and the waveguide layer is connected with the upper surface of the first cladding; the optical beam splitter provided by the invention can achieve the effects of low insertion loss, uniform light splitting and low phase error in a large bandwidth range; the gaps in the grating structure of the waveguide layer can be stably filled by the glass layer formed by spin-coating the glass reagent, air gaps are prevented from occurring when the gaps in the grating structure are filled, the manufacturing reliability of the beam splitter is improved, and the optical beam splitter can be suitable for large-scale optical calculation and optical interconnection scenes.

This application provides a phase tracking method, apparatus, device, and medium for a multi-user system receiver, applied to a target WiFi receiver; the method includes: demodulating an ultra-high throughput modulated signal to obtain a corresponding ultra-high throughput signal field, extracting each user-specific configuration block of the ultra-high throughput signal field, verifying the user-specific configuration block to obtain a verification result, determining a joint pilot set based on the verification result, and performing phase tracking based on the joint pilot set using a digital phase-locked loop.

The utility model relates to the technical field of coaxial loudspeakers, in particular to a coaxial loudspeaker with a novel structure, which comprises a frame, one end of the frame is sequentially provided with a washer, magnetic steel and T iron, the inner wall of the frame is provided with a cone, the cone is provided with a dustproof cap, one end of the cone is provided with a damper and a voice coil, and the other end of the cone is provided with a loudspeaker. One end of the basin stand is provided with a mounting frame, the other end of the basin stand is provided with a mounting frame, the mounting frame is provided with an opening, the mounting frame is provided with an arc-shaped panel, a phase plug is arranged between the arc-shaped panel and the opening, and a mounting mechanism is arranged between the arc-shaped panel and the mounting frame. The novel coaxial loudspeaker can flexibly adapt to various cone depths and radians and dust caps with different shapes, and the application range of the novel coaxial loudspeaker in different audio application scenes is widened.

The application discloses a kind of optical fiber gyro inertial platform angular vibration transmission characteristic test methods, including synchronous acquisition position angular vibration table excitation angle signal and the frame angle signal of optical fiber gyro inertial platform;According to the frame angle signal of optical fiber gyro inertial platform, the method for obtaining optical fiber gyro inertial platform attitude angle signal is adopted navigation solution, and it is relevantly operated, and relevant characteristic function is obtained;According to the relevant characteristic function, the amplitude-phase characteristic solution of stable loop is carried out, and the amplitude of stable loop and the phase of stable loop in optical fiber gyro inertial platform are obtained;The application also discloses a kind of optical fiber gyro inertial platform angular vibration transmission characteristic test system, including position angular vibration table, optical fiber gyro inertial platform, optical fiber platform ground test system, position angular vibration table control cabinet and electric control box.The application can be applied to the transmission characteristic evaluation of optical fiber gyro inertial platform angular vibration, with higher accuracy and flexibility.

This application provides a broadband filtering 180° phase shifter, chip, and device based on magnetically coupled path switching, including an RF input terminal, a magnetically coupled path switchable network, a matching network, and an RF output terminal. The magnetically coupled path switchable network includes a first inductor, second and third inductors forming positive and negative magnetic couplings with it respectively, and first and second transistors connected to the second and third inductors respectively. The matching network includes first and second series matching units and a parallel matching unit. By alternately controlling the transistors to be on and off, the phase shifter exhibits a consistent third-order bandpass response in both the reference state and the phase-shifted state: the first capacitor and the first inductor at the input terminal are connected in parallel to form a first resonator; the off transistor and the connected inductor form a second resonator; the on transistor grounds the corresponding series matching unit, forming a third resonator with the parallel matching unit, and another series matching unit provides inter-stage coupling. This application achieves broadband high-amplitude phase consistency, significantly improving phase-shifting accuracy.

The utility model relates to the technical field of antennas, in particular to a low-profile single-station direction-finding antenna array of small mobile equipment. According to the technical scheme, a low-profile capacitor loading monopole antenna with a short-circuit probe is designed, and a three-unit array is formed. The array can be directly printed and manufactured on a common circuit board, and the integration level of a direction finding system is improved. The source direction of the signals is calculated by comparing the phase differences of the signals received by the units of the array, so that the direction finding function is completed. Besides, the antenna is connected with the computing chip through the coplanar waveguide printed on the circuit board, and the high-precision circuit board printing ensures the consistency of the sizes of the three units of the direction-finding array, so that the phase error of the circuit between the antenna units and the chip is eliminated.