31results about How to "Improve signal-to-noise ratio" patented technology

A method and apparatus for processing radio-frequency (RF) signals suitable for magnetic-resonance imaging (MRI) and/or magnetic-resonance spectroscopy (MRS) from radio-frequency (RF) coils that have strongly-coupled coil loop pairs, each pair including a transmit loop and a receive loop, wherein the transmit loop and the receive loop are of equal sizes and shapes and in close proximity to each other, and wherein a suitable attenuated and phase-adjusted version of a transmit pulse is subtracted from a receive signal obtained from tissue being examined to improve signal-to-noise ratio (SNR) of the received signal.

A longitudinally segmented acoustic transducer for a cement bond logging (CBL) tool having a plurality of adjoining PZT ring-like segments driven synchronously in parallel by one or more pulses and caused to vibrate in an anti-resonant mode, substantially below the resonant frequency of an individual segment when used in a transmitting application. When used in a receiving application, each of the plurality of transducer rings are caused to vibrate by acoustic signals detected by the transducer array, also in an anti-resonant mode. High speed digital signal processing enables on-depth, high quality data for all azimuths at each depth to be obtained, processed, normalized and either sent to the surface in real time for each 20 Hz firing cycle, as the CBL tool is pulled toward the surface, or stored in a memory module in digital form for later retrieval. Built-in calibration factors used for normalizing the output signals to the operating conditions of use may be accessed at any time.

The embodiment of the invention discloses a three-dimensional target imaging method and device. The method comprises the steps of performing conjugate transpose processing on a distance domain echo vector with pulse response and a distance domain reference signal matrix corresponding to the distance domain echo vector with the pulse response to obtain a space domain echo vector and a space domainreference signal matrix; extracting a space domain echo vector with pulse response of each division region of a two-dimensional imaging plane; constructing a space domain reference signal matrix corresponding to the space domain echo vector with the pulse response; imaging each division region of the two-dimensional imaging plane; and performing three-dimensional target imaging on an image of eachdivision region of the two-dimensional imaging plane. By extracting the space domain echo vector with the pulse response in the space domain echo vector, noise is eliminated, and the signal-to-noiseratio is improved; and moreover, y division of a two-dimensional imaging plane region, parallel independent imaging of each region of the two-dimensional imaging plane is performed, the reference signal matrix scale is reduced, and the calculation capability and the calculation accuracy are improved.

The invention discloses an MEMS capacitive sensor with an automatic range, which comprises an MEMS capacitance sensitivity module, a capacitance/voltage conversion module, an A/D module and a microprocessor, wherein the MEMS capacitance sensitivity module is a capacitor formed by a sensitivity movable structure and a fixed structure; the sensitivity movable structure sensitively detects mechanical deformation generated by a to-be-measured physical quantity; the capacitance/voltage conversion module converts the capacitance change quantity into a voltage signal; and the A/D module samples the voltage signal and outputs the voltage signal to the microprocessor. Through adjusting a DC bias voltage difference at two ends of the capacitor, the magnification times of a sensitive element can be adjusted, and the range of the sensor can be adjusted to a set range. The detection range of the MEMS capacitive sensor can be expanded, and especially for a weak to-be-measured quantity, the signal-to-noise ratio of the sensor can be improved, and the weak signal detection precision is increased.

The invention discloses an unmanned aerial vehicle signal frequency point detection method in a complex electromagnetic environment, and the method comprises the steps: S1, employing an array antenna with a mirror image characteristic, and carrying out the adaptive signal cancellation; s2, performing equal-gain combination on the multiple paths of cancellation signals to obtain a synthesized signal; s3, threshold detection is carried out on the synthesized signal, an effective signal bandwidth is extracted, and unmanned aerial vehicle signal bandwidth information, a time domain envelope period and pulse width information are obtained; and S4, according to the obtained unmanned aerial vehicle signal bandwidth information, the time domain envelope period and the pulse width information, matching to obtain an unmanned aerial vehicle model, and carrying out unmanned aerial vehicle signal identification. The method has the advantages of simple principle, simplicity and convenience in operation, wide application range, capability of remarkably improving the detection capability and the like.

A test structure for integrated electronic circuits having a substantially planar substrate coated with a plurality of metallization layers comprises a switching element formed on the surface of the substrate. It also comprises a tunnel formed in one or more metallization layers between the top of the switching element and the front side of the integrated circuit. This tunnel is designed to channel photons emitted by the switching element towards the front side.

The present invention relates to a high-speed dynamic pressure gyro motor ground touch rotating speed test system, and relates to the motor test field. The high-speed dynamic pressure gyro motor ground touch rotating speed test system comprises a motor control unit, a sensor unit, a high-speed data acquisition unit, a central processing unit, a voltage comparison unit, a signal conditioning unit, a communication unit, an upper computer data analyzing and resolving unit, a test result displaying and storing unit, etc., can measure the ground touch rotating speed of a motor and detect the characteristic of a dynamic pressure gas bearing accurately, and can further obtain the state characteristic indexes of a dynamic pressure bearing. The system of the present invention adopts a counter electromotive force measurement method, can measure the characteristic parameters of the motor under the states, such as a floater, a gyro instrument, an inertial platform, etc., and enables the problem that after being assembled, the gyro motor only can measure the current and the voltage, but can not measure other characteristic parameters to be solved effectively. The measurement system can evaluate the operation state of the gyro motor real-timely, and has very important actual engineering significance for enhancing the reliability of a gyro instrument product and improving the quality and precision of a dynamic pressure motor product.

The invention discloses a white light interference measurement device and method based on sample space structure illumination. A micro-display is added to an illumination system, and different space patterns can be projected to the surface of a sample; during measurement, a measurement area of the sample is divided according to an acquired sample image in combination with characteristics of the sample to form different illumination patterns; the illumination patterns are input into the micro-display, and asynchronous spatial illumination and white light interference measurement are carried outon adjacent areas, so as to avoid coherent interference signal interference caused by multiple reflections between adjacent points; and then, the plurality of groups of measured surface height distributions are combined to obtain the height distribution of the whole surface. Interference between adjacent points during white light interference measurement of samples such as a micro-groove array issuppressed by adopting a spatial pattern illumination method, and the samples can be quickly detected in a nondestructive manner.

The invention relates to a transient electromagnetic duality emitting device. The transient electromagnetic duality emitting device comprises a receiving coil and duality emitting coils, wherein the duality emitting coils are arranged at the upper end and the lower end of a fixed device respectively and are in mutual series connection, the receiving coil is fixed in the middle position of the fixed device, and the receiving coil is mutually perpendicular to the upper duality emitting coil and the lower duality emitting coil. The duality emitting coils are arranged at the two ends of the fixed device in a winding mode, the winding directions of the duality emitting coils are opposite, the distance between the duality emitting coils can be adjusted according to detection requirements, series connection circuits of the duality emitting coils are used for supplying electricity to the coils, and primary filed signals are stimulated. The coefficient of mutual induction of the transient electromagnetic duality emitting device is obtained to be zero according to the relation of the coefficient of mutual induction and the relative positions of the coils, the mutual inductance caused by current changes in a transmitting coil and the receiving coil can be effectively reduced, and the signal to noise ratio is improved. The duality emitting coils are adjustable, duality emitting is achieved, transient electromagnetic lateral propagation energy can be increased, and the lateral detection depth can be increased ultimately. The transient electromagnetic duality emitting device is simple in operation and can be operated by any constructor.

The invention discloses a separated cavity packaging structure of an integrated sensor. The structure comprises an MEMS (Micro-Electro-Mechanical System) chip, an ASIC chip, a circuit board, a shell and an environment sensor. The shell and the circuit board form a packaging body. A first packaging cavity and a second packaging cavity which are mutually isolated are arranged in the packaging body. The MEMS chip and the ASIC chip are located in the first packaging cavity. The environment sensor is located in the second packaging cavity. The second packaging cavity is equipped with a through hole communicated with an external environment. A sound hole channel is arranged in the circuit board. The inlet of the sound hole channel aligns with the MEMS chip. The outlet of the sound hole channel is communicated with the second packaging cavity. According to the separated cavity packaging structure, the MEMS chip is communicated with the second packaging cavity through the sound hole channel in the circuit board; the back cavity is increased; the product performance is improved; moreover, the sensing speed of the environment sensor is improved through the large through hole; the external airflow or dusts are not liable to enter into the first packaging cavity through the sound hole channel; and therefore, bad influences resulting from the external airflow or dusts on the MEMS chip are eliminated.

The invention provides an airline communication method and system, a computer readable storage medium and electronic equipment. The method comprises the steps of selecting a target base station byan airborne ATG on the ground from a local base station site map according to GPS position information provided by a position server; after the airborne ATG aligns the direction angle of an airborne antenna to the selected target base station, sending an uplink message to the target base station by using beam forming; and the airborne ATG receives a downlink message fed back by the target base station by adopting beam forming so as to establish a beam pair for communication between the airborne ATG and the target base station. In the invention, the beam forming technology is simultaneously adopted at the airborne ATG and the ground base station end to improve the channel capacity and improve the signal-to-noise ratio of the system, and the antenna direction is adjusted in real time through information such as a GPS (Global Positioning System) and the like, so that the antenna control problem caused by ultra-long-distance coverage and a high-speed moving scene in the ATG system is solved.

The invention discloses an automatic laser average optical power control system for a burst mode. The system comprises a laser driver, an analog-digital modulation circuit and a digital control circuit. The analog-digital modulation circuit comprises an integrator, a comparator and a trigger D, the average output optical power of a laser is converted into currents proportional to the average output optical power through a photodiode, the integrator converts the proportional currents into average currents and inputs the average currents into the comparator for judgment, the average currents are converted into numeric code type signals through output of the comparator via sampling of the trigger D, the numeric code type signals are input to a digital controller, and the digital controller outputs different signals according to numeric code types to adjust output of the laser driver so as to adjust the average output optical power of the laser. The automatic laser average optical power control system can meet the demands of the burst mode and is higher in applicability.

The present invention relates to a device which uses optical fibers to form a tube hat for a finger tip to collect all Raman photons.

The invention relates to a distributed fiber-sensing measuring method. The method comprises the following steps: a, laying sensing fiber cable, wherein the sensing fiber cable comprises a first segment and an overlap segment, one end of the first segment is connected with a measuring host, the overlap laying area comprises a second segment and a return segment, and the sensing fiber cable senses environment parameters, and different points on the second segment and the return segment can sense the parameters in the same position of the space; and b, processing signals, wherein signals returned from the first segment are processed to obtain the outside parameters of the area in which the first segment is positioned, and signals returned from points on the second segment and the return segment corresponding to the same space point are processed to obtain the parameters of the same space point. The invention also provides a distributed fiber-sensing measuring device. The invention has advantages of reducing the fluctuation at the tail end of the sensing fiber, increasing the actual measurement length, simpleness and convenience, economy and the like.

The invention discloses a large-field-of-view correlated imaging device and an imaging method. The imaging device comprises a pulse light source, a light modulation unit, a directional scanning projection unit, a light receiving unit, a central processing unit, a display unit, which are sequentially arranged along a light path, and a control unit connected with the directional scanning projection unit, the light modulation unit and the central processing unit. The divergence angle of an emergent light beam is adjusted through the directional scanning projection unit, so that light energy intensively irradiates a local area of a field of view to obtain an extremely high signal-to-noise ratio, and the imaging distance is increased. According to the invention, any large-range view field imaging can be achieved by setting the types and parameters of the light beam directional scanning mechanisms and combining the image splicing technology, the application range of the device is widened, view field expansion can be achieved only through one or a few scanning mechanisms, and the device is low in machining and assembling difficulty and high in stability. The image resolution of the imaging device is determined by the light modulation unit, and the directional scanning mechanism does not influence the image resolution.

Methods and apparatus for trapping or guiding ions. Ions are introduced into an ion trap or ion guide. The ion trap or ion guide includes a first set of electrodes and a second set of electrodes. The first and second sets of electrodes are arranged to define an ion channel to trap or guide the introduced ions. Periodic voltages are applied to electrodes in the first set of electrodes to generate a first oscillating electric potential that radially confines the ions in the ion channel, and periodic voltages are applied to electrodes in the second set of electrodes to generate a second oscillating electric potential that axially confines the ions in the ion channel.

The invention relates to a method for removing abnormal noise in single-point reception of seismic record by a digital detector, belonging to seismic data processing. The method comprises the following steps: obtaining a weighted median for a trace adjacent to each frequency sample point relative to an amplitude spectrum; comparing the median and an amplitude value of each frequency sample point, and calculating a weighted value if the amplitude value is more than a threshold value; attenuating a trace where the frequency sample point is located in a frequency space field to obtain a noise frequency spectrum; carrying out inverse transformation on the noise frequency spectrum to obtain time and space field noise; detracting noise from the original record, removing the abnormal value of the frequency field, and changing and calculating residual strong energy interference in an envelope trace attenuation record. The invention effectively attenuates abnormal noise, can effectively remove high-frequency interference and abnormal energy interference in the record and improves the signal-to-noise ratio of the seismic data.

The invention discloses a microwave-optical frequency modulation transfer technology-based cesium microwave atomic clock and an implementation method. The microwave-optical frequency modulation transfer technology-based cesium microwave atomic clock comprises a cesium atom vacuum system, a laser system, a photoelectric signal detection system, a microwave frequency source, a phase modulator and anintegrated circuit system; the microwave frequency source is connected with the phase modulator; the phase modulator is connected with the circuit comprehensive system and the cesium atom vacuum system; the photoelectric signal detection system is connected with the circuit comprehensive system and then connected with the microwave frequency source; error signals are obtained through modulation transfer detection between microwaves and optical frequency of the atomic dielectric clock, and dispersion type error signals used for frequency locking of the crystal oscillator are obtained. The microwave-optical frequency modulation transfer technology-based cesium microwave atomic clock has the advantage of high signal-to-noise ratio of the clock transition spectral line, directly obtains the dispersive error signal, does not need an external phase-locked amplifier for modulation and demodulation, effectively reduces the size and complexity of the system, reduces the noise interference, achieves the high-precision locking of the clock laser frequency, and greatly improves the signal-to-noise ratio and stability of the atomic clock.