291results about How to "Achieve modulation" patented technology

A backlight module, a method for identifying a fingerprint under the screen, a device and an electronic device are provided. The fingerprint recognition device is applied to an electronic device having a backlight module, and the fingerprint recognition device includes: a fingerprint recognition module. The fingerprint recognition module is disposed under the backlight module, and the fingerprintrecognition module is configured to receive the infrared light signal emitted by the infrared light source and illuminate the human body finger and pass through the backlight module. The infrared light signal is used to detect the fingerprint information of the finger. The haze of the infrared light signal when passing through the backlight module is smaller than the haze when the visible light for displaying an image passes through the backlight module. An screen fingerprint recognition device of the embodiment of the present application can effectively implement the screen fingerprint recognition of the passive light-emitting display.

The invention provides a spin angular momentum-orbital angular momentum hybrid modulation quantum secret key distribution method and system. The spin angular momentum-orbital angular momentum hybrid modulation quantum secret key distribution system comprises a hybrid spin angular momentum-orbital angular momentum generation unit, a spin angular momentum modulation unit, an orbital angular momentum modulation unit, and a coincidence measurement decoding unit. The hybrid spin angular momentum-orbital angular momentum generation unit is used for generating spin angular momentum-orbital angular momentum hybrid entanglement quantum states. The spin angular momentum modulation unit is used for conducting phase position deflection modulation on the spin angular momentum of signal photons. The orbital angular momentum modulation unit is used for conducting phase position deflection modulation on the orbital angular momentum of idle photons and loading coded information. The coincidence measurement decoding unit is used for conducting coincidence measurement on the signal photons and the idle photons to decode quantum bit information. The safety of the spin angular momentum-orbital angular momentum hybrid modulation quantum secret key distribution system is improved, large-capacity quantum coding is achieved, and the quantum secret key distribution system is efficient in coding, simple in structure and high in safety.

The invention discloses a nanocrystalline enhanced tungsten oxide electrochromic film which is a 'TCO nanocrystalline-WO3 amorphous' biphase composite film prepared by taking transparent conductive oxide (TCO) nanocrystalline and amorphous tungsten oxide as substrates. The invention further discloses a preparation method of the nanocrystalline enhanced tungsten oxide electrochromic film. The nanocrystalline enhancing technology is adopted to improve the electrochromic performance of a traditional tungsten oxide film at the visible light waveband, meanwhile, by virtue of the modulating characteristic of the TCO nanocrystallines at the near infrared waveband, modulation of the tungsten oxide film at the near infrared waveband is realized, and accordingly, the problems in the prior art that the tungsten oxide film is not long enough in cycle life and is low in electrochromic response rate of big-sized materials and lack of near infrared modulation capability are solved.

The invention relates to a graphene optical Q-switch and an application. The graphene optical Q-switch comprises a SiC substrate and a grapheme material growing on the SiC substrate. One surface carrying the grapheme faces the inner side of the laser cavity while the other surface faces the outer side of the laser cavity. The graphene optical Q-switch is used in the laser, pump light passes through the graphene optical Q-switch after passing through the laser gain medium and the SiC substrate is used as an output mirror and forms a resonant cavity with the front cavity mirror in front of the laser gain medium. The invention can adjust loss of laser generated by visible light, infrared or ultraviolet light. The Q-switch has the advantages of simple preparation, low cost, achievable adjustment of laser with large wavelength range and is beneficial to industrialized production and the like.

The invention provides a method for transmitting broadcast message in a wireless communication system. The method comprises the following steps: (a) a base station selects a channelization code used by a main broadcast channel of a cell according to the cell identification on physical layer of the cell; and (b) the base station uses the channelization code to spread the spectrum of the main broadcast channel of the cell and transmit the main broadcast channel of the cell. Compared with other methods for transmitting broadcast message, the method in the invention can effectively eliminate interference generated by a broadcast channel of adjacent cell in a synchronous network, improve the accuracy of a user device for receiving broadcast message, and reduce time for cell searching, thereby improving the frequency spectrum of a system.

A networking method of an ad hoc network comprises the following steps: step A, in a networking stage, a PAN coordinator broadcasts a networking notice to adjacent nodes of the PAN coordinator, receives a network access request returned by each adjacent node in response to the networking notice, and selects part or all of nodes from nodes allowed to access the network as current relay nodes; stepB, the current relay node broadcasts a networking notification to the adjacent nodes, receives network access requests returned by the adjacent nodes in response to the networking notification, and sends the network access requests of the adjacent nodes to a PAN coordinator; step C, the PAN coordinator receives the network access request of each neighbor node of the current relay node to determinea newly added network access node, and selects the current relay node from the newly added network access nodes; and step D, the step B and the step C are repeated until a preset networking completion condition is met, and networking is completed. According to the networking method of the ad-hoc network, routing can be flexibly planned based on the communication condition among the nodes in the ad-hoc network during networking.

A wireless energy and data transmission system for visual prostheses in the technical field of biomedical engineering, including: an external wireless device located outside the body, an internal wireless device located inside the body, and a data reverse transmission module. The external wireless device receives encoded images After the signal is modulated, it is transmitted wirelessly to the wireless device in the body. The wireless device in the body rectifies and demodulates and receives the driving power and the received signal respectively. The data reverse transmission module monitors the impedance and temperature information in the body, and transmits the data to the external coil through the internal coil , the external reverse demodulation circuit recovers the impedance and temperature information, and the external device adjusts the input power according to the state in the body. The invention has the characteristics of simple circuit, small volume, high efficiency and the like.

The invention discloses an in-band full duplex underwater acoustic communication apparatus capable of suppressing interference from a digital domain and an analog domain. The full duplex underwater acoustic communication apparatus comprises a transmitting unit and a receiving unit, wherein the transmitting unit comprises a modulator, a digital-to-analog converter, a power amplifier and a transmitting transducer, and the receiving unit comprises a receiving hydrophone, a low-noise amplifier, an analog-to-digital converter and a demodulator. A receiving terminal is subjected to interference of near-end local transmitting signals while receiving remote signals and thus cannot acquire correct demodulated signals. According to the invention, a method for eliminating interference in the analog domain is selected to eliminate the interference, and part of self-interference can be eliminated. Furthermore, a method for eliminating interference in the digital domain is adopted, so that self-interference and inter-symbol interference are completely avoided. The underwater acoustic communication apparatus disclosed by the invention eliminates interference from the analog domain and the digital domain, thereby realizing in-band full duplex underwater acoustic communication in a real sense.

The invention discloses a planar waveguide type near-and-mid infrared light modulator based on graphene-chalcogenide glass, and belongs to the technical field of electro-optical modulators. The optical modulator solves the problems in modulation and demodulation of integrated photonic devices based on optical signals of near-and-mid infrared light ranging from 1.55 microns to 3 microns. The modulator comprises a substrate layer, ridge-shaped light waveguide layers, a first strut and a second strut, wherein the ridge-shaped light waveguide layers, the first strut and the second strut are arranged on the substrate layer; a first graphene layer and a second graphene layer are arranged on the ridge-shaped light waveguide layers; the first graphene layer extends to the upper surface of the first strut, and the second graphene layer extends to the upper surface of the second strut; isolation medium layers are arranged between the ridge-shaped optical waveguide layer and the first graphene layer, between the ridge-shaped optical waveguide layer and the second graphene layer, between the first graphene layer and the second graphene layer, between the first graphene layer and the first strut, and between the second graphene layer and the second strut respectively; a first electrode is arranged on the first graphene layer on the first strut, and a second electrode is arranged on the second graphene layer on the second strut. The modulator is used for signal modulation and demodulation in the integrated photonic devices.

The present invention relates to a mixed code type optical signal transmitting device, and comprises a laser, a signal generation device and a dual-drive Mach- Tsende modulation device. The laser is used for generating optical carriers which are transmitted into the dual-drive Mach- Tsende modulation device; the signal generation device is used for generating mixed electric signals of amplitude modulation and multi-ary phase modulation, which are transmitted into the dual-drive Mach- Tsende dual-drive Mach-Tsang Tak modulation device; the dual-drive Mach- Tsende dual-drive Mach-Tsang Tak modulation device is used for generating the mixed code type optical signals which combine the amplitude modulation and the multi-ary phase modulation, which are generated by the modulation of the electric signals. The present invention also relates to a mixed code type optical signal transmission method. The transmission method can not only transmit outwards the mixed modulation code type which combines the return-to-zero code of carrier suppression and the multi-ary phase shift keying code, but also can modulate the amplitude information of the mixed modulation code type, so as to generate the mixed code type optical signals which combine the amplitude modulation and the multi-ary phase modulation.

The invention discloses a carrier modulation method of a two-stage matrix converter. The carrier modulation method includes that an application control system samples network voltage, duty ratios of an effective current vector and a zero vector are calculated according to a relative position angle of a rectifier-stage input current space vector, and modulation signals of a rectifier stage are calculated according to the duty ratios of the effective current vector and the zero vector; an equivalent average value of direct-current bus voltage in a modulation period is calculated, and modulation signals of an inverter stage are calculated by combining the duty ratio of the effective current vector and the duty ratio of the zero vector; control signals of a rectifier-stage power switch and an inverter-stage power switch of the two-stage matrix converter are generated according to the modulation signals of the rectifier stage and the inverter stage. Carrier modulation is performed on the basis of the current space vector, so that generation of narrow pulses is inhibited, unbalancing of input voltage is inhibited, modulation process of the two-stage matrix converter is simplified, and the carrier modulation method has good application prospect and practical value.

The invention relates to an analogue-signal isolated transmission system for measuring high voltage, and pertains to the technical field of high voltage measurement. The system comprises: a laser light source for generating a linear polarization light beam; a signal modulator for coupling the linear polarization light beam with the signal modulator through a polarization-retaining optic fiber; a photoelectric converter for converting the optic power signals got after modulation by the signal modulator into voltage signals, which is connected with the signal modulator through a single-mode optic fiber; an electric signal detector for detecting the voltage signals output by the photoelectric converter, which is connected with the photoelectric converter through a radio-frequency cable. The invention can meet the isolated transmission of analogue and digital signals; the whole transmission system is an inactive system, with a wide application range; uses optic signals to communicate, which effectively avoids any disturbance in transmission, and is applicable for measuring hi-voltage area; the signal modulator in the system is of rapid response speed, high sensibility, and has improved the measuring frequency range and response speed.

The invention discloses an optical IQ modulator arbitrary bias point control method and system. The control method comprises: calculating a first type of correlation integral coefficient by using a first disturbance signal and a second disturbance signal; obtaining the characteristic voltage rough values of respective modulators according to a relationship between bias voltages and the first typeof correlation integral coefficients; obtaining the characteristic voltage accurate values of respective modulators by using an iterative method and the characteristic voltage rough values of respective modulators; calculating the bias voltages required to be loaded onto respective modulators at a target bias point, and correspondingly setting the bias voltages required to be loaded onto respective modulators; calculating the value of a second type of correlation integral coefficient by using a third disturbance signal, and accordingly calculating a reference correlation coefficient vector; obtaining a real-time correlation coefficient vector, calculating an error voltage, and then correspondingly adjusting the bias voltages of respective modulators by using the error voltage. The method and system can control any bias point of an optical IQ modulator and maintain the stability of the bias point.

The invention provides a radar echo simulating method and a radar echo signal simulator. The method comprises the steps of receiving a radar emission signal through a controller; respectively performing first delay processing for each PRF in the radar emission signal through a first storing device, and generating and outputting an emission delay signal; respectively performing second delay processing for each modulation information data in modulation signal through a second storing device, and generating and outputting a modulation delay signal; enabling the pulse drop edge of each modulation information data in the modulation delay signal to be in front of the pulse raise edge of the PRF corresponding to each modulation information data, so as to ensure matching and aligning; performing convolution operation for the emission delay signal and the modulation delay information through the controller, and generating and outputting a radar echo simulating signal; delaying and modulating the radar emission signal. With the adoption of the method, the problem of simulating echo distortion can be avoided.

The invention discloses anatase titanium dioxide nano-rods and a preparation method thereof. According to the invention, titanium alkoxide is adopted as a titanium source, an organic alkali is adopted as a glue solution, ethylene glycol-water or ethylene glycol-water-ethanol is adopted as a solvent; low-temperature glue solution is carried out, and then high-temperature hydrothermal reaction is carried out; and crystal growth is controlled in a manner of oriented bonding, such that the morphology of a final product is controlled in a special nano-rod shape. The oriented bonding direction is a (001) direction, and a crystal exposed surface is a {101} surface. With different reaction conditions, the diameters of the nano-rods are adjustable within a range of 5-60nm, and the lengths of the nano-rods are adjustable within a range of 50-400nm. According to the nano-rod growth process, a plurality of anatase grains are subjected to local bonding fusion according to a certain optimized direction through crystal lattice match sharing common crystal surfaces, such that the nano-rods with certain length-to-diameter ratio, good dispersion, and huge specific surface area is formed. With an electrode material prepared by using the nano-rods, higher electron collection efficiency can be easily obtained, and high photoelectric performance is provided.

The invention discloses a three-level NPC inverter neutral point potential equalization control method based on neutral point current. Upper and lower capacitor voltage and neutral point current are sampled in real time, the upper capacitor voltage and the lower capacitor voltage are compared to obtain a capacitor voltage difference value, voltage equalizing regulating quantities are obtained according to the capacitor voltage difference value, neutral point current polarity and three-phase original modulating wave polarity to regulate the three-phase modulating waves v<ma>, v<mb> and v<mc>, thereby obtaining three-phase modulating waves v<ma'>, v<mb'> and v<mc'>, the three-phase modulating waves are compared with triangular carriers C<up> and C<down>, and a PWM signal is output to control the on-off state of an inverter switching tube, thereby realizing regulation of neutral point potential. In the method provided by the invention, since pulsation frequency of the voltage equalizing quantities is larger than carrier frequency, the method for regulating the neutral point potential has a high frequency characteristic, can realize regulation of the neutral point potential in an NPC inverter in a very short time, and is good in real-time performance and high in control precision.

The invention discloses a thermo-optical modulator based on a graphene microring structure. The thermo-optical modulator comprises insulated silicon-on-substrate as a substrate. A straight waveguide and an annular resonant chamber are adjacently arranged on the insulated silicon-on-substrate. A square graphene conducting layer is arranged above the straight waveguide and the annular resonant chamber. A first electrode layer and a second electrode layer without overlapping are arranged above the other end of the graphene conducting layer. According to the thermo-optical modulator, the graphene directly contacts with a silicon microring waveguide. Heat which is generated by the graphene is changed through controlling the voltage which is applied on the graphene, and finally light modulation in the silicon microring is realized. The thermo-optical modulator can be prepared in a relatively easy manner. Furthermore a microring resonant cavity is very sensitive. Furthermore because of a relatively large thermo-optic coefficient of the silicon, strong optical modulation can be realized. Furthermore because of an ultrahigh thermal conductivity of the graphene, dynamic response of the device is improved to a relatively large extent.

The invention provides a squeeze-type asymmetrical double-core optical fiber switch, which comprises an asymmetrical double-core optical fiber, a stackable piezoelectric ceramic squeezing device and an adjustable voltage source. Two 3dB couplers are synthesized on the asymmetrical double-core optical fiber in a fused biconical taper manner, and the two couplers form a Mach-Zehnder interferometer; a ballast direction of a piezoelectric ceramic stack is perpendicular to the axial direction of the optical fiber, a fixed angle is formed between the piezoelectric ceramic stack and the position of double cores, and the piezoelectric ceramic stack is located between the two couplers. The squeeze-type asymmetrical double-core optical fiber switch is simple in structure and easy to manufacture; light paths are ensured to be relatively steady, and influence caused by environment factors, such as vibration, temperature and the like, can be effectively avoided; insertion loss is low, performance of whole optical fiber electro-optic modulation is improved, and modulation on an optical switch in a signal optical fiber can be implemented; and a modulation length necessary for the optical fiber is very short, and the shortest length can be only a few millimeters.

The audio switch type AC induction motor has stator and rotor iron cores comprising punched sheets of soft magnetic material or ferrite with proper frequency characteristics. The rotor is in squirrelcage structure and the stator magnetic poles operate in switching excitation mode with exciting voltage being pulse width or amplitude modulated voltage in audio or ultra-audio range. In the condition of the same output power, the motor of the present invention has volume and weight several times or over ten times smaller, low production cost, excellent mechanical characteristic and step-less speed regulation from zero to several thousand rpm.

The invention discloses a plasmon-structured substrate and a preparation method and an application thereof. The plasmon-structured substrate comprises a substrate, a reflective layer, an insulating layer, a metal nano-structure array and a positive electrode and a negative electrode; a perovskite device enhanced substrate is prepared based on a plasmon field enhancement principle initially; and byvirtue of a physical method, absorption limited expansion of the perovskite material in an infrared light waveband and absorption enhancement in the whole absorption region are realized, so that negative effects caused by chemical doping of a perovskite layer is avoided.

The invention provides an optical device, a system and an optical apparatus, the optical device is composed of a plurality of parts, light rays satisfying a predetermined characteristic propagate on an interface of the plurality of parts in one manner, and light rays not satisfying the predetermined characteristic propagate on the interface in another manner. According to the invention, at least part of parts with matched tooth surfaces are adopted, and the ambient light is equivalent to transmitting a flat medium and is not influenced by the parts to change the focal power. And the image light is equivalently reflected by a reflector with focal power after being reflected by the tooth-shaped structure of one part, so that the focal power of the image light is changed.

The invention relates to a metamaterial base station antenna housing and an antenna system. The metamaterial base station antenna housing is covered on an antenna and comprises at least one metamaterial sheet layer, wherein each of the metamaterial sheet layer comprises a substrate and a plurality of artificial microstructures arranged on the substrate in an array; the substrate can be divided into a plurality of metamaterial units, and each of the metamaterial units is configured with one artificial microstructure; each of the artificial microstructure comprises a cross-shaped structure arranged at the center of the metamaterial unit and four circular ring structures arranged in four quadrants divided by the cross-shaped structure respectively. According to the invention, the artificial microstructures with special shapes are adhered to the substrate, the relative dielectric constant, the refractive index and the impedance of the material are changed through adjusting the shape and the size of the artificial microstructures, thereby reinforcing transmission of electromagnetic waves, and improving the directivity and the gain of the antenna.

The invention discloses an adjustable and controllable optical flow control dye laser based on an electrorheological effect. A system in the prior art has the defects of complexity, incapability of adjusting and controlling and very high requirement on the preparation process. The electrorheological effect and an optical flow control technology are combined to form an adjustable and controllable optical resonant cavity, thereby constructing a tunable laser with an electric field adjusting and controlling laser output mode. Incident pump beams are form a converged pump light field after being subjected to beam shaping and spatial light modulation in sequence; the resonant cavity is a cylindrical cavity, two circular end faces are high-reflecting surfaces for forming optical feedback, the cavity is filled with a dye suspension, and the cavity is provided with an electrode for an external control electric field, thereby realizing an electric field adjusting and controlling optical resonance condition and a laser emitting mode. The adjustable and controllable optical flow control dye laser has the advantages of the conventional optical flow control laser as well as the characteristics of adjustable resonance cavity performance, controllable output beam mode, simplified system structure, simple preparation process, high miniaturization degree, good beam quality, axially symmetric optical pumping, high pumping optical energy utilization ratio and the like.

The invention discloses a compact drive system and drive method for an open-winding permanent magnet synchronous motor. Middle points of a first bridge arm, a second bridge arm and a third bridge arm of a four-bridge arm compact converter are connected to left-end windings A, B and C of the open-winding permanent magnet synchronous motor respectively; the first bridge arm, the second bridge arm and the third bridge arm form a left three-phase power output end; the middle point of the fourth bridge arm is connected with a right-end winding A' of the open-winding permanent magnet synchronous motor; the right-end windings B' and C' are connected with the left-end windings A and B; the first bridge arm, the second bridge arm and the fourth bridge arm form a right three-phase power output end; a current signal collection module collects a current signal of the open-winding permanent magnet synchronous motor; a position signal collection module collects a voltage signal of the open-winding permanent magnet synchronous motor; a current signal and a voltage signal are transmitted to a controller to achieve rotating speed current double closed-loop control; and a drive module outputs a PWM signal to achieve control on the four-bridge arm compact converter. The system is low in cost and good in speed control performance. The invention further discloses a compact drive method for the open-winding permanent magnet synchronous motor.