153results about How to "Suppression of common mode noise" patented technology

The present invention belongs to the field of fine surface structure measuring technology, and relates to one kind of differential confocal scanning detection method with high spatial resolution. Differential confocal microscopic double receiving light path configuration and double detector subtraction form the differential confocal signal in measuring the workpiece. Optical super-resolution confocal microscopic detection method is adopted to raise the transverse resolution, and differential confocal microscopic detection method is adopted to raise the longitudinal resolution, so as to reach differential confocal scanning detection of high spatial resolution. The method can meet the requirements in high spatial resolution, high precision and great measurement range, and is especially suitable for the measurement of fine surface 3D structure, miniature steps, miniature grooves, line width, surface appearance, etc.

The invention belongs to the technical field of optical precision measurement, relating to super-resolution laser polarization differential confocal imaging method and device. The method improves the transverse resolution power by combining a radial polarized light and a pupil filtering technology, improves the axial resolution power by using a differential subtraction detection technology of an axial-offset dual-detector system and remarkably improves the spatial resolution power and tomography ability of the system. The device comprises a laser source as well as a beam expander, a polarization state modulation system, a pupil filter and a spectroscope which are sequentially arranged at a transmitting end of the laser source, an objective and a sample which are arranged in the transmitted light direction of the spectroscope in turn, and a differential confocal system in the opposite direction of the reflected light direction of the spectroscope. The invention combines the radial polarized light resolution technology with the pupil filtering technology and improves the transverse resolution power of the system; moreover, the differential work mode of the invention can remarkably improve the axial imaging ability of the system and is applicable to the high-precision detection and metering of nanometer-level geometrical parameters in the nanometer manufacturing field.

In a filter circuit (1), a common mode choke (2) and a normal mode choke (3) have extremely high and low impedances, respectively, for common mode signals received through two input terminals (1a and 1b). The chokes have the opposite impedance characteristics for differential signals. In particular, the difference in impedance is large. Furthermore, the normal mode choke (3) is installed as a previous stage of the common mode choke (2). Accordingly, common mode noises which enter the two input terminals (1a and 1b) penetrate the normal mode choke (3), but neither penetrate the common mode choke (2) nor are reflected from the common mode choke (2). In particular, common mode currents flow through the normal mode choke (3) but do not flow through the common mode choke (2).

A filtering device is capable of suppressing common mode noises upon transmission of a differential signal, and includes a differential transmission line, a grounding layer, a dielectric unit and a conductive structure. The differential transmission line has a pair of conductive traces spaced apart from each other. The grounding layer is spaced apart from the differential transmission line. The dielectric unit is disposed between the differential transmission line and the grounding layer. The conductive structure is embedded in the dielectric unit, is coupled electrically to the conductive traces and the grounding layer, and cooperates with the differential transmission line, the grounding layer and the dielectric unit to form a stacked structure that has an effective negative permittivity, thereby suppressing the common mode noises coupled to the conductive traces. A differential signal transmission circuit is also disclosed.

A multilayer structure in which all the magnetic elements have the windings edged in the inner layers and the magnetic core which surrounds the winding has the legs penetrating through the multilayer structure. The interconnection between the magnetic elements and the rest of electronic components is done through the layers of the multilayer board, horizontally and vertically through via. For higher power components special cuts are performed in the multilayer board to accommodate the body of the components which may be connected to an external heatsink. The winding arrangement in the transformer is done in a such way to minimize and even eliminate the common mode noise injected through the capacitance between primary and secondary winding. The input filter is constructed to exhibit a differential and a common mode impedance. Supplementary capacitors are incorporated in the multilayers structure to offer a low impedance to the noise to short it to the source, or for injecting currents of opposite polarity to cancel the common mode current transferred through the transformer's inter winding capacitance and through the parasitic capacitance of the switching elements to the secondary. The insulation between winding can be in accordance with the safety agency requirements, allowing much shorter creapage distances inside of the multilayer PCB structure than in the air due to the compliance with coating environment.

The invention discloses a compound color super resolution differential confocal measuring device and comprises a first super resolution differential confocal measuring device, a second super resolution differential confocal measuring device, a dichroic mirror, a partial color difference correction objective lens as well as a computer device. According to the chromatic dispersion characteristics that the focusing of optical beams with different wavelength produces an ideal translation of focusing surface, the device forms two partly overlapped linear measuring areas and achieves two linear measuring areas with the characteristics of double-polar tracking, and therefore, not only measuring range expands for nearly one times, but also cross tracking measurement of the measuring area is realized; according to the application requirement, unanimous or inconsistent transverse or axial scanning characteristics can be achieved respectively in the two linear measuring areas with independent modulation of a multi-super resolution filter, moreover, on the condition of remaining the advantages of the differential and super resolution differential confocal measuring technology, the invention expands the linear range of the measuring device significantly.

The invention provides a nuclear magnetic resonance gyroscope based on wide spectrum laser pumping. The nuclear magnetic resonance gyroscope comprises a light path detection part, a pumping light path part, a polarized light path part, a photoelectric detection part, a signal demodulation circuit, an atomic gas chamber, a heating body, a magnetic compensation coil, a magnetic shielding body, an aluminum alloy shell, a laser drive power supply, a temperature control circuit and a magnetic field drive circuit. According to the nuclear magnetic resonance gyroscope, alkali metals are polarized by adopting broadband laser pumping, the line width of broadband laser is more than a superfine energy level splitting gap, and the polarizability of a working medium can be effectively improved. Moreover, an external magnetic field is attenuated by adopting the magnetic shielding body, current is applied to generate a magnetic field in the magnetic compensation coil so as to compensate the residual magnetic field, so that a disturbing magnetic field is effectively isolated. Furthermore, detected light is divided into two paths for performing detection and reception, a gyro signal can be acquired by virtue of difference processing, and gyro common-mode noise can be effectively suppressed.

The invention provides a touch screen data processing method for inhibiting noise and a touch screen control device which applies the method. The method comprises the following steps: (1) receiving an analog signal of a touch screen, and sampling the analog signal of the touch screen to obtain a digital signal; (2) according to a sampling value, calculating a reference value corresponding to the sampling point; (3) comparing the sampling value and the corresponding reference value to obtain a deviation, and comparing the deviation with a preset threshold value; (4) if the deviation is smaller than the threshold value, keeping the sampling value, abandoning the sampling value if the deviation is greater than the threshold value, and replacing the sampling value with the corresponding reference value obtained by the calculation; and (5) applying the data obtained in the step (4) to touch information processing, and calculating a touch position. The method can effectively inhibit common-mode noise and improve the detection precision of a touch position. Compared with a traditional noise elimination method, the touch screen data processing method has the following outstanding advantages of being simple in calculation method, small in hardware resource occupation when a touch signal is realized and high in processing speed, is not affected by the length of a scanning signal and can calculate the signals of any length.

Provided are common mode filtering method and device for use with a defected ground structure, the device including a substrate, coupled microstrip lines formed on the substrate and a ground plane formed underneath the substrate, the common mode filtering method being characterized by forming at least a defected ground structure on the ground plane and making dual mode signals pass through the coupled microstrip lines, thereby using the defected ground structure to suppress dual model noises within a specific frequency band and prevent signal distortion.

The invention belongs to the technical field of microscopicspectral imaging detection, and relates to a split pupil laser differential confocal Raman spectrum test method and device. According to the test method and device, a split pupil laser differential confocal microtechnique and a laser Raman spectrum detection technique are organically combined, precise imaging of three-dimensional geometrical positions is realized through segmentation focal spot differential detection, the optical path structure of a traditional differential confocal microscopic system is simplified, advantages of an original laser differential confocal system and a split pupil confocal system are inherited, and multi-mode switching and processing of split pupil laser differential confocal microscopic detection, laser confocal Raman spectrum detection and laser differential confocal Raman spectrum detection can be realized only through softwareswitching processing. The test method and device provide a new technological approach for detection ofnanoscale microcell three-dimensional geometrical positions and spectrum, can be applied to fields of biomedicine, industrial precision detection and the like, and has the broad application prospect.

The invention discloses a brain-computer interface communication system based on asymmetric visual evoked potential. The system comprises a liquid crystal display, an electroencephalogram electrode, an electroencephalogram amplifier and a computer processing platform, wherein the liquid crystal display is used for displaying a stimulation interface; the electroencephalogram electrode is used for collecting an electroencephalogram biological signal; the electroencephalogram amplifier is used for amplifying the signal through the electroencephalogram amplifier and inputting the amplified signal into a computer after carrying out filtering; the computer processing platform is used for designing and executing commanding codes based on a peripheral view asymmetric visual stimulation according to induction characteristics of the asymmetric VEP (Visual Evoked Potential), and finally, the electroencephalogram signal is decoded and converted into a BCI (Brain-Computer Interface) instruction to be output. Compared with a traditional visual BCI system, the brain-computer interface communication system based on asymmetric visual evoked potential can reduce the visual feeling of fatigue of a subject, meanwhile, the information transmission efficiency of the BCI system is improved, a perfect brain-computer interface system can be obtained through further researches, and considerable social benefits and economic benefits can be possibly caused.

The invention relates to super-resolution dual-axis differential confocal measurement method and device for division focal spot detection, which belong to the technical field of optical precision measurement. By utilizing the characteristic that the transversal deflection of a detector makes the axial response curve of the dual-axis confocal microscopy generate displacement, adopting the transversal differential detection method of a division focal spot to receive and process a measuring optical beam in the dual-axis confocal microscopy, and combining a super-resolution pupil filtering technology, the method and the device achieve the purposes of enhancing the system resolution, extending the working distance, enhancing the anti-jamming capability and improving the linear range. The invention can be used for the precision measurement of microelectronics, materials, industry precision detection, biomedical field and the like.

The invention provides an underwater acoustic signal real-time extraction method based on the laser orthogonal polarization interference technology, relating to the underwater acoustic signal real-time extraction method based on the laser orthogonal polarization interference technology. An existing method lacks flexibility, the detection of an underwater wide range moving sound source can not be satisfied, only the detection of the static characteristic of an underwater sound source can be carried out, the real-time extraction of an underwater sound signal can not be realized, and the above problems are solved by the method of the invention. A passive homodyne interferometer system is constructed; an initial coordinate system is established; a laser outputs a single-frequency laser beam to go through a collimating lens and a polarizer to be linearly polarized light, a 45-degree angle is formed by the vibration direction of the linearly polarized light and an X axis, the linearly polarized light goes through a polarized beam splitting prism 1 to be splitted into two beams of polarized light whose vibration directions are perpendicular to each other, and the polarized light is marked as S light and P light; the S light is reflected by the polarized beam splitting prism 1 as reference light, P light is used as detection light, photodetectors detect signals, and the phases of the detected signals are obtained by using a demodulation way. The method is applied to the field of underwater signals.

The invention discloses a programmable analog unit for processing a sensor signal, which comprises a first programmable switched capacitor group, a second programmable switched capacitor group, a programmable main fully differential operation amplifier, a first programmable auxiliary fully differential operation amplifier, a second programmable auxiliary fully differential operation amplifier, an output multiway selector and an output control module, wherein the first programmable switched capacitor group is used for receiving an external sensor differential signal; the second programmable switched capacitor group is used for receiving an external sensor differential signal; the programmable main fully differential operation amplifier is used for generating and outputting a main fully differential signal after signal processing; the first programmable auxiliary fully differential operation amplifier is used for generating and outputting an auxiliary fully differential signal; the second programmable auxiliary fully differential operation amplifier is used for generating and outputting an auxiliary fully differential signal; the output multiway selector is used for selecting and outputting one way of differential output signal; and the output control module is used for generating and outputting a positive-negative reverse-phase or modulated differential output signal. The programmable analog unit for processing the sensor signal can read out small capacitance and small voltage sensing signals and process analog signals, is applied to sensor signal detection of physical quantities such as an angular velocity, an accelerated velocity and the like, and is suitable for circuits of an FPAA (field programmable analog array), a FPMA (fixed preassigned multiple access) and a PSOC (programmable system on chip).

The present invention belongs to the field of optical microscopic imaging and micro measurement technology, and is one 3D three-differential confocal microscopic imaging method with very high S / N ratio and 3D super resolution imaging capacity. The present invention fuses the three-differential confocal scanning method with high axial resolution and pupil filtering confocal scanning method with high transverse resolution to constitute the 3D pupil filtering three-differential confocal microscopic imaging method. The method may be used in measuring 3D surface appearance, 3D fine structure, micro step, micro channel, IC line width, etc.

The invention provides a device and method for measuring a smooth free-form surface sample based on differential STED, and belongs to the field of optical microscopic measurement. The surface of the smooth free-form surface sample is plated with a fluorescent film, and by the utilization of the characteristic that the fluorescent film radiates fluorescence in various directions under laser radiation, the problem that signal light is difficult to collect due to specular reflection of light beams on a smooth free-form surface is solved; meanwhile, by the adoption of the STED microscopy principle, light spots formed by collecting two pulse laser beams of different wavelengths coincide with each other, the portions, located in the center regions of the light spots, of the fluorescent film on the sample excite fluorescence, the portions, located in the light spots but not located in the center regions of the light spots, of the fluorescent film generate back excitation and do not emit fluorescence, and therefore super-resolution imaging of the sample is achieved; by the adoption of a differential detection structure, differential operation is conducted on two paths of collected signals, a differential response curve is acquired, the surface position of the sample is determined through a zero point of the differential response curve, and finally the purpose of measuring the smooth free-form surface sample shape with the large curvature at high accuracy is achieved.

The invention discloses a real-time absolute ranging method and system based on single-chamber dual-femtosecond optical comb cross-correlation analysis. The method comprises steps: S1, two simultaneously-outputted femtosecond optical combs with different repetition frequencies are generated, the two different repetition frequencies are fr1 and fr2, and the repetition frequencies are locked to an atomic clock by frequency stabilization control; S2, after the beam of the two femtosecond optical combs passes through an interferometer optical path module, the orthogonal polarization components ofoptical comb pulse return light (reference light and measurement light) and local optical comb pulses are measured, and after combination, two groups of femtosecond laser pulse pairs with mutually-perpendicular polarization directions are generated; S3, two-path optical balance cross-correlation signals for reference and measurement are generated, and the signales can be generated by a femtosecondpulse cross-correlation analysis unit in the embodiment of the invention; and S4, the balance cross-correlation signals are subjected to high-speed digital signal analysis processing to obtain a ranging result. The system is the device used for executing the above method. The method and the system disclosed in the invention have the advantages of large ranging range, fast updating speed, high measuring precision and simple operation and the like.

The invention belongs to optical microscope imaging and microcosmic measurement field, which relates to an integral ring light three-difference cofocal microscope with high signal-to-noise ratio and three-dimension super resolution imaging ability; it mainly includes laser, beam expanding device, polarization spectroscope, lambda / 4 wave plate, microscope lens, gathering lens; and pin apertures and detectors, it also includes a ring light integral device whose incidence light is ring type between the beam expanding device and the polarization spectroscope, adjusts the adjustable diaphragm. The invention improves the transverse resolution of the microscope.

A receiving circuit of an RS 485 receiver is provided. The receiving circuit includes a first stage fully-differential amplifier, a second stage fully-differential amplifier, a bi-directional hysteresis comparator and an output controller which are connected in series with one another, wherein the first stage fully-differential amplifier adjusts common-mode electrical level, the second stage fully-differential amplifier amplifies differential-mode electrical level, and the output controller controls output through enabling. When receiving is enabled, the receiver performs output normally, and when receiving is disabled, the receiver outputs high electrical level, and therefore, common-mode noise and high-frequency differential-mode noise can be greatly suppressed, and receiving sensitivity can be improved.

A filtering device is capable of suppressing common mode noises upon transmission of a differential signal, and includes a differential transmission line, a grounding layer, a dielectric unit and a conductive structure. The differential transmission line has a pair of conductive traces spaced apart from each other. The grounding layer is spaced apart from the differential transmission line. The dielectric unit is disposed between the differential transmission line and the grounding layer. The conductive structure is embedded in the dielectric unit, is coupled electrically to the conductive traces and the grounding layer, and cooperates with the differential transmission line, the grounding layer and the dielectric unit to form a stacked structure that has an effective negative permittivity, thereby suppressing the common mode noises coupled to the conductive traces. A differential signal transmission circuit is also disclosed.

The invention belongs to the technical field of optical precise measurement and relates to a super-resolution double-shaft differential confocal measuring method and a super-resolution double-shaft differential confocal measuring device. In the method and the device, pupil filtering technology is fused in a double-shaft confocal measuring structure, and a differential treatment method is used for receiving a measured light beam and carrying out treatment, thereby achieving the aims of improving resolution, expanding working distance, improving anti-interference capability and improving linear range. The invention can be used for precise measurement in such fields as micro-electronics, materials, industrial precise detection, biomedicine, etc.

The invention provides a planar transformer, a power switching circuit, and an adapter, capable of improving noise suppression performance. The planar transformer comprises a primary winding includinga first primary winding layer, a secondary winding including a first secondary winding layer, and a charge balance winding. The first secondary winding layer is provided with Ns1th turns to (Ns1+B1-1)th turns coils of the secondary winding. The charge balance winding comprises a first charge balance winding layer which is arranged between the first primary winding layer and the first secondary winding layer and is adjacent to the first primary winding layer and the first secondary winding layer. A first charge balance winding layer is provided with N1 turns of coils, wherein N1 is larger thanor equal to Nb1. When the planar transformer works, an average value of first induction voltage generated by the Nb1 turns of coils is equal to the average value of second induction voltage generatedby the first secondary winding layer, wherein N1 and Nb1 are positive number.

The invention belongs to the technical field of optical precise imaging test, and relates to a laser stimulated emission depletion (STED) and three-dimensional superresolving differential confocal imaging method and device. The method and device are characterized in that the laser differential confocal detecting technology and the laser STED imaging technology are organically integrated, the laser differential confocal technology is performed to improve the axial resolution capacity, and while the STED technology is performed to improve the transverse solution capacity, so that the spatial resolution capacity of the system can be improved. The device comprises an excitation laser system, a first dichroic mirror, a quarter-wave plate, an objective lens, a sample, a scanning workbench, a quenching laser system, a beam shaping system, a second dichroic mirror, a differential confocal detecting system and a data processing system. The method and device have an extensive application prospect in the micro-nano technical field with the high spatial resolution three-dimensional superresolving imaging and detecting capacities.

The invention discloses a swept source based common-channel optical coherence tomography (OCT) system and method. The system comprises a broadband swept source, a three-terminal circulator, a probe, an interference system and a control processing system. The probe comprises a GRIN lens and an MEMS (micro-electromechanical system) mirror. Laser emitted by the broadband swept source enters the probe via the three-terminal circulator, part of the laser is converged via the GRIN lens in the probe, the laser after being reflected from the probe via the MEMS mirror is irradiated onto a sample to perform one-dimensional or two-dimensional scanning on the sample so as to obtain sample information, and the converged laser with the sample information returns to the three-end circulator to form reference light. Sample light and the reference light enter the interference system via the three-terminal circulator to form an interference signal, and the interference signal enters the control processing system to be processed to form a sample image. By the OCT system and method, the reference light is provided directly through the end face of the GRIN lens replacing an independent sample arm, and the structure is simple.

The present invention is related to a filtering device with slotted ground structure, comprising a first substrate, a second substrate and a pair of differential signal lines, in which a ground plane having slotted ground structure is provided between the first substrate and the second substrate. Each of the two differential signal lines is symmetric to each other and comprises a first line segment being horizontally provided on the top surface of the first substrate and a second line segment being horizontally provided on the bottom surface of the second substrate, respectively. The first line segment is connected to the second line segment through a vertically disposed conductive via. Thereby, a common-mode noise within a specific frequency band may be suppressed effectively, so as to avoid interference a differential-mode signal transmitted on the differential signal lines, due to the slotted ground structure etched on the ground plane.

The invention discloses a camera image transmission device based on a PCI-E (Peripheral Component Interconnected Express) interface. The camera image transmission device comprises a first mainboard and a second mainboard, wherein the first mainboard is connected with a to-be-tested camera by virtue of a camera parallel interface and is provided with a first FPGA (Field Programmable Gate Array) with a first programming configuration chip, a storage and a level conversion circuit; the second mainboard is connected with a computer host provided with testing software by virtue of the PCI-E interface; the second mainboard is provided with a clock module, a second FPGA provided with a second programming configuration chip and a PCI-E bridging chip provided with a local configuration chip; the PCI-E bridging chip exchanges data with the computer host by virtue of a PCI-E transport protocol and exchanges data with the second FPGA by virtue of a local bus transport protocol; the second FPGA on the second mainboard is connected with the first FPGA on the first main board by virtue of an LVDS (Low-Voltage Differential Signaling) interface. The camera image transmission device disclosed by the invention can be used for realizing image data transmission based on the PCI-E interface, greatly improving the test rate of the camera with high pixels and improving the production efficiency.

The invention discloses a transformer shielding layer design method for a flyback switching power supply. The transformer shielding layer design method comprises the steps of 1) measuring and estimating structures and electrical parameters of a transformer; 2) setting a shielding layer length as the circumference of the layer, setting the thickness according to actual supply, wherein the position of the layer is set based on a proper value; obtaining structural capacitance between a primary side winding and a secondary side winding of the transformer, and structural capacitance between the secondary side winding and a shielding copper foil layer under different shielding layer widths in a simulation manner through finite element software analysis; 3) calculating common-mode evaluation equivalent capacitance in the transformer under the different shielding layer widths, and drawing a common-mode equivalent capacitance-shielding layer width characteristic curve; and 4) obtaining the shielding layer width when the common-mode evaluation equivalent capacitance is equal to 0 according to the drawn characteristic curve, wherein the obtained shielding layer width is the optimal shielding layer width for restraining common-mode current of the transformer. Compared with the existing common-mode restraining technology, the transformer shielding layer design method has the advantages of simple realization, low cost, capability of reducing the volume and the weight of the common-mode filter, obvious restraining effect, and the like.

A flexible printed circuit board comprises at least a signal layer, wherein two grounding layers are respectively arranged above and below the signal layer; two insulation dielectric layers are respectively arranged between the signal layer and the adjacent grounding layers; a differential pair is distributed on the signal layer and comprises two differential transmission lines; grounding conductive materials are respectively arranged on the two grounding layers along the transmission directions of the differential transmission lines and are positioned in the orthographic projection areas of the areas enclosed by the two differential transmission lines on the two grounding layers; and hollow areas exist within certain distances from the two sides of the grounding conductive materials. The flexible printed circuit board can effectively prevent common mode noise during transmitting high-speed differential signals.

The invention discloses a CMOS / MEMS compatible spectroscopic gas sensor which performs qualitative and quantitative analysis by using near-infrared transmission spectra of gases to be measured. The sensor consists of an infrared light source, a photon crystal dispersing prism, an infrared photoelectric detection array and the like, judges the type of gases by adopting the reference structure and analyzing the position of the characteristic line and determines concentration of gases by corresponding absorbance. The invention overcomes the deficiencies that the traditional MEMS gas sensor has complex processes and short service life, has the high sensitivity detectivity and can be manufactured compatible with CMOS processes. The CMOS / MEMS compatible spectroscopic gas sensor can be produced in large scale with reduced cost and analyze the gas concentration gradient through the integrated array.