35results about How to "Narrow frequency band" patented technology

A micromachined design and method with inherent disturbance-rejection capabilities is based on increasing the degrees-of-freedom (DOF) of the oscillatory system by the use of two independently oscillating proof masses. Utilizing dynamical amplification in the 4-degrees-of-freedom system, inherent disturbance rejection is achieved, providing reduced sensitivity to structural and thermal parameter fluctuations and damping changes over the operating time of the device. In the proposed system, the first mass is forced to oscillate in the drive direction, and the response of the second mass in the orthogonal direction is sensed. The response has two resonant peaks and a flat region between peaks. Operation is in the flat region, where the gain is insensitive to frequency fluctuations. An over 15 times increase in the bandwidth of the system is achieved due to the use of the proposed architecture. In addition, the gain in the operation region has low sensitivity to damping changes. Consequently, by utilizing the disturbance-rejection capability of the dynamical system, improved robustness is achieved, which can relax tight fabrication tolerances and packaging requirements and thus result in reducing production cost of micromachined methods.

A multi-beam, polarization diversity, narrow-band cognitive antenna system is disclosed. The antenna system includes a plurality of antenna elements, switching elements, and transmission feed lines disposed on a PCB substrate, inside or on the enclosure of a consumer wireless device, on the airframe of an air vehicle, or on the surface of a ground vehicle. The plurality of switching elements are arranged with the antenna elements and transmission feed lines to, when selectively closed, electrically couple selected ones of the antenna elements and transmission feed lines to one another to generate an antenna configuration selected from a plurality of antenna configurations. A non-volatile memory is configured to store data representing at least some of the plurality of antenna configurations. A control arrangement operatively coupled to the plurality of switching elements and configured to close selected ones of the switching elements as a function of the data stored in said memory. Means are provided to selectively update the data on a function of previously selected antenna configurations.

In an antenna that has high sensitivity to frequencies of narrow bands and over a wide band and that can be small-sized, and in a wireless module, wireless unit and wireless apparatus using this antenna, the antenna is comprised of a transmission line, and variable capacitance means connected to this transmission line, and the variable capacitance means controls the resonant frequency.

A method for accurately determining internal failures, such as separations, of a tire without affecting tire behaviors. Radial acceleration signals of a tire during vehicular travel are detected by an acceleration sensor (11) attached to the inner surface of the tire at the axial center of the tread. A frequency analysis is performed on the radial acceleration signals to obtain a frequency spectrum. A band value Xab is calculated of a specific frequency band [fa, fb] within the range of 100 Hz-400 Hz, which includes the frequency of the second lowest peak of the peaks appearing in the frequency spectrum. Then a check is made to see whether or not the difference between this band value Xab and a predetermined band value Yab of a normal tire exceeds a threshold value K. And when Yab−Xab>K, it is determined that an internal failure, such as a separation, is present in the tire.

A method for nondestructive inspection of ceramic structures present as either a ceramic matrix composite structure or a ceramic based coating. Such non-metallic structures are used to provide thermal protection or weight reduction or both to aircraft and their components. The nonmetallic structure is scanned with an electromagnetic pulse in the range of 200 GHz to 4 THz. The electromagnetic pulse includes a plurality of frequencies within the Terahertz range and is not restricted to a single designated frequency. The frequency range is sensitive to changes in impedances and refractive index within the structure. After the electromagnetic pulse passes through the nonmetallic structure, it may be evaluated for changes in impedance in the nonmetallic structure at different locations, and, when present, whether the changes in impedance impact the ability of the structure to perform the function for which it was designed.

Provided is a gyroscope self-calibration device and method. The gyroscope self-calibration device comprises a signal generator and a signal processing circuit, wherein the signal generator is used for producing modulating signals including a drive signal and an electric excitation signal, the modulating signals are used for driving a gyroscope to output a current signal having a phase shifting component, the signal processing circuit is used for processing the current signal output by the gyroscope to obtain a voltage value, and the angular velocity of the electric excitation signal in the modulating signals and the voltage value form linear relation. The gyroscope self-calibration device adopts the modulating signals to replace a traditional high-precision physical turntable and completes self calibration of the gyroscope. Therefore, a factory-leaving standardization calibration procedure of the gyroscope is simplified, and the self calibration cost is reduced. In the usage process of the gyroscope, a user can perform self calibration of the gyroscope in real time, so that device parameter change produced due to device ageing, environment temperature change, system noise and the like is avoided in the using process of the gyroscope, and reduction of the precision of the gyroscope is avoided.

The invention discloses a far-infrared environment-friendly coating. The far-infrared environment-friendly coating is characterized by comprising the following substances in parts by weight: 1-5 parts of clay, 2-6 parts of mineral thermal insulation materials, 25-30 parts of fire retardants, 1.5-2.5 parts of defoaming agents, 0.5-2.5 parts of fungicides, 30-40 parts of silicone modified epoxy resin, 10-16 parts of mixed solvents, 4-10 parts of dispersants, 1-6 parts of polyolefin plastic, 2-9 parts of tourmaline crystal mine micro-powder and 3-9 parts of inorganic fillers. According to the far-infrared environment-friendly coating, by utilizing a nanometer technique, the crystal lattice of a prepared far-infrared radiation material is greatly changed, the frequency band is narrow, the pertinence is strong, the radiation rate is high, the toughness of an element is greatly improved, the heat shock stability is good, and the far-infrared environment-friendly coating further has a very wide application prospect in a normal temperature state.

In an antenna that has high sensitivity to frequencies of narrow bands and over a wide band and that can be small-sized, and in a wireless module, wireless unit and wireless apparatus using this antenna, the antenna is comprised of a transmission line, and variable capacitance means connected to this transmission line, and the variable capacitance means controls the resonant frequency.

The invention discloses a colloidal crystal-modified optical fiber-capillary microstructural device, which is manufactured by the following main steps of: removing a coating from the common standard monomode optical fiber, inserting the optical fiber into a capillary, fixing the optical fiber by using glue, and polishing a capillary-optical fiber end face; preparing colloidal microsphere solution from different materials such as polystyrene (PS), polymethyl methacrylate (PMMA) and silica; growing a colloidal crystal on the capillary-optical fiber end face by a vertical deposition method, sintering by using a sintering furnace and curing to form a colloidal crystal capillary-optical fiber microstructure; and packaging and fixing by using a thermoplastic sleeve and a plastic box. The formed colloidal crystal-modified capillary-optical fiber microstructure can have a porous structure and can be manufactured into an optical fiber filter and a biological environmental sensor through further development; and the common optical fiber is utilized, so the device is easy and convenient to manufacture and low in cost.

The invention discloses electrostatic induction measurement method and device for local particle velocity in a fluidized bed. The method comprises the following steps of: packing an insulating and isolating material on one end of a metal shield pipe to form an insulating and isolating block, uniformly arranging a plurality of electrodes in parallel in the insulating and isolating block on the same plane to form a first electrostatic induction electrode array and a second electrostatic induction electrode array, and respectively connecting all electrodes in the two electrode arrays by using conducting wires; producing two groups of electrostatic signals reflecting gas-solid flowing information when electrified particles pass through the two electrostatic induction electrode arrays; and amplifying the electrostatic signals by a front-end charge differential circuit, sending to a computer through a data acquisition card, analyzing the spectrum of the differential electrostatic signals in the computer, and determining the peak frequency on the spectrum so as to further acquire the local particle velocity of a gas-solid two-phase flow. The electrostatic induction measurement device for local particle velocity in the fluidized bed comprises a measurement probe, a front-end charge differential amplifying circuit, the data acquisition card and the computer.

A nano-class far infrared radiation material for saving oil of engine aging wine, and disinfecting drinking water is prepared through adding the micron-class powder of Fe2O3, NiO and TiO2 to nano-class mixture powder, ball grinding for at least 72 hrs, shaping and calcine. The said nano-class mixture powder contains zirconium silicate, clay, talc, nickel oxide, cobalt oxide, ferrous oxide, titanium oxide, zinc oxide and MnO2.

A recordable optical information medium includes a recording area including a guide groove on which a recording material layer is provided for forming at least one recording mark which represents first information modulated by a first modulation system; and a pit area including at least one concave and convex type pit which represents second information modulated by a second modulation system. The guide groove and the at least one pit have substantially the same depth. The first modulation system and the second modulation system are different from each other.

Modulating certain parameter (such as frequency, phase or amplitude) of radio frequency signal for sound signal to be magnified obtains a radio frequency signal carrying information of sound signal to be magnified. Using high frequency amplifier magnifies the radio frequency signal, and then demodulating the magnified radio frequency signal restores sound signal. When high-frequency signal is magnified, the sound signal is also magnified indirectly.

The disclosure provides an emergency ultrasonic detection system and method for trace gas leakage of a small pressure vessel. The system comprises a sensor module and a signal processing circuit module. The sensor module comprises a piezoelectric ceramic sensor that is arranged in front of a leakage point to be detected and is formed by connecting four piezoelectric crystal elements in parallel; the signal processing circuit module comprises an amplifying circuit and a filter circuit; the amplifying circuit comprises an amplifying chip; the amplifying circuit is connected to the filter circuit; a probe of the piezoelectric ceramic sensor comprises a first port and a second port, the first port and the second port are respectively connected to an amplifying chip through circuits connected with resistors in series, one of the two circuits between the resistors and the amplifying chip is connected with a resistor and a capacitor which are connected in parallel, and the other circuit is grounded through the resistor. According to the technical scheme, real-time online detection can be carried out on the running container, normal work is not influenced, and parts do not need to be dismounted for detection.

The invention discloses a novel X-band all-solid-state transmitter, relates to the technical field of microwave measurement. The transmitter comprises a feed network, two-stage GaAs power amplifiers,a first amplification module, a microstrip isolator, a first microstrip coupler, a first coaxial waveguide converter, a second amplification module, a waveguide bi-directional probe coupler and a waveguide ring / isolator, wherein the two-stage GaAs power amplifiers, the first amplification module, the microstrip isolator, the first microstrip coupler, the first coaxial waveguide converter, the second amplification module, the waveguide bi-directional probe coupler and the waveguide ring / isolator are connected in sequence. The input end of the first-stage GaAs power amplifier serves as the inputend of the all-solid-state transmitter to be connected with radio frequency signals, and the output end of the waveguide ring / isolator serves as the output end of the all-solid-state transmitter to be connected with an antenna port. The feed network is used for supplying power to the two-stage GaAs power amplifier, the first amplification module and the second amplification module; micro radio-frequency signals input to the all-solid-state transmitter are amplified by four stages of the two-stage GaAs power amplifier, the first amplification module and the second amplification module to output high-power radio-frequency signals, and the high-power device is ensured to have better power synthesis efficiency through two groups of power distributors / synthesizers.

A communication method for a radio LAN system provides communication at a first transmission rate. In the method, a first signal of the first transmission rate is time-divisionally distributed into n−1 second signals (n=3, 4, . . . ). The n−1 second signals are respectively converted into n−1 third signals of a second transmission rate less than the first transmission rate. The n−1 third signals of the second transmission rate are also transmitted through radio transmission paths between n−1 radio base stations and a terminal station connected to at least one terminal unit.

The invention discloses electrostatic induction measurement method and device for local particle velocity in a fluidized bed. The method comprises the following steps of: packing an insulating and isolating material on one end of a metal shield pipe to form an insulating and isolating block, uniformly arranging a plurality of electrodes in parallel in the insulating and isolating block on the same plane to form a first electrostatic induction electrode array and a second electrostatic induction electrode array, and respectively connecting all electrodes in the two electrode arrays by using conducting wires; producing two groups of electrostatic signals reflecting gas-solid flowing information when electrified particles pass through the two electrostatic induction electrode arrays; and amplifying the electrostatic signals by a front-end charge differential circuit, sending to a computer through a data acquisition card, analyzing the spectrum of the differential electrostatic signals inthe computer, and determining the peak frequency on the spectrum so as to further acquire the local particle velocity of a gas-solid two-phase flow. The electrostatic induction measurement device forlocal particle velocity in the fluidized bed comprises a measurement probe, a front-end charge differential amplifying circuit, the data acquisition card and the computer.

The present invention relates to a method and an apparatus for suppressing passive wireless earphones through a pulsed magnet field. According to the method, a continuous pulse wave with the pulse duty factor of 50%:50% and a continuous pulse wave with the pulse duty factor changing within the range from 75%:25% to 25%:75% are adopted, a magnetic field coil is directly driven by superposition of base wave pulses and high-order harmonic pulses, an auditory discrimination mode of human is simulated, and reception of passive wireless earphones is suppressed, so as to interfere and destroy information transmission paths and conditions of cheating-used earphones. Various interference pulse signals are generated by a single chip microcomputer, and power complementary pair transistors are directly driven, the technology and the method are mature, reliable and easy to operate, and audio language classrooms or laboratory site facilities can be directly utilized.

The invention discloses an environmental protection biomaterial, which comprises the following substances by weight: 10-16 parts of clay, 21-26 parts of urea-formaldehyde resin, 16-20 parts of polytetrafluoroethylene gum, 14-16 parts of tartrate, 9-13 parts of methyl benzoate, 10-13 parts of polyvinyl alcohol, 3-6 parts of talcum powder, 1-3 parts of murraya paniculata wood chip, 2-6 parts of Ixora Chinensis wood chip, 9-12 parts of geranium wood chip, 2-6 parts of methyl phenyl siloxane branched prepolymer, 3-6 parts of oilseed straw powder, 12-14 parts of turnip straw powder, 1-6 parts of hollow glass bead and 2-3 parts of graphite powder. The environmental protection biomaterial employs a nano technology, the crystal lattice of prepared Far-IR radiation material has large change, and has the advantages of narrow frequency band, strong pertinency, high radiant ratio, greatly increased element toughness, and good thermal shock stability; and has wide application prospect under normal temperature state.

The invention discloses a weak signal detection device with strong anti-interference performance, the weak signal detection device comprises a filter circuit, a pre-amplification circuit, a lock-in amplifier, a multi-channel amplification circuit, a multi-channel AD acquisition circuit, a DSP, a CAN box and an upper computer which are electrically connected together in sequence, the filter circuitreceives signals, and the lock-in amplifier comprises a modulation module. The device disclosed by the invention is used for a direct current signal or a slow change signal with smaller amplitude; inorder to prevent adverse effects of 1 / f noise and direct current drifting (such as temperature drifting of input offset voltage of an operational amplifier) of direct current amplification, a modulator or a chopper is generally used for converting the direct current drifting into an alternating current signal, then the alternating current signal is amplified and processed, and then demodulation and low-pass filtering are carried out to obtain an amplified detected signal. The weak signal detection device designed based on the lock-in amplifier shows excellent performance in the aspect of weaksignal detection.

The invention discloses an NAVTEX message modulation method based on an FPGA, and relates the field of navigation radio communication and software radio. According to the method, the design of an NAVTEX modulator is achieved by using the FPGA according to the properties of an NAVTEX message, as shown in Fig.1, firstly, received effective data are stored in real time by using the ping-pong cache technology so as to accomplish the seamless buffering and processing of the data; then, the NAVTEX message is encoded by using the 4B3Y error detecting code encoding mode, thereby greatly improving the correctness and reliability of digital information transmission; the NAVTEX message is modulated by using an F1B modulation mode, thereby greatly improving the occupancy rate of the frequency band and enhancing the anti-jamming property of the transmission; and finally the modulated message is sent to a transmitter by using a data sending module to accomplish the sending. According to the NAVTEX message modulation method disclosed by the invention, the NAVTEX message modulation is achieved based on the FPGA, various functional modules of the FPGA are completely compiled by using the VHDL language, therefore few resources are occupied, the modularized design and use are convenient, the performance is more stable and reliable, and thus the NAVTEX message modulation method is very suitable for maritime radio communication.

A filter includes a multilayer body including a plurality of insulator layers stacked on top of one another. Outer electrodes are provided on surfaces of the multilayer body. A first resonator is connected to a first one of the outer electrodes and includes a first coil. A second resonator is connected to a second one of the outer electrodes and includes a second coil. A third resonator includes a third coil that is magnetically coupled with the first and second coils. The first and second coils are respectively defined by coil conductor layers provided on an insulator layer. The third coil is defined by via hole conductors that penetrate through the insulator layer in a z-axis direction.

The invention discloses a non-intrusive pipeline liquid pressure measuring method based on an ultrasonic longitudinal wave reflection technology. According to the method, the pressure value of the liquid in the pipeline is indirectly measured by utilizing different sound velocities of the liquid in the pipe wall under different pressures and temperatures; measurement errors caused by installation of an ultrasonic transducer, a coupling agent and circuit delay are eliminated through the longitudinal wave reflection time of ultrasound in the pipe wall, accurate measurement of the transmission time of liquid in the pipeline is achieved, and a mathematical model of the transmission time of the liquid in the pipeline, the liquid temperature and the pressure value of the liquid in the pipeline is established. The measuring device adopts a circuit design structure which takes an MS1030 time digital conversion chip as a main part and takes high-speed ADC data acquisition as an auxiliary part to carry out ultrasonic transmission time measurement, takes a microprocessor as a core, controls ultrasonic signal sending and receiving time and temperature measurement, converts the time into a pressure value through corresponding mathematical calculation, and displays the pressure value. The problem of non-intrusive pressure measurement required by special occasions is effectively solved.

The invention discloses a nano far infrared environment-friendly paint, which is composed of the following raw materials in parts by weight: 1 to 5 parts of clay, 2 to 6 parts of mineral heat insulation material, 5 to 9 parts of filling material, 1 to 8 parts of film forming auxiliary agent, 3 to 8 parts of cosolvent, 12.5 to 15 parts of anionic powder, 12.5 to 15 parts of far infrared ceramic powder, 4 to 9 parts of wetting agent, 2 to 6 parts of dispersant, 0.5 to 2.5 parts of bactericide, and 30 to 40 parts of organic silicon modified epoxy resin. A nano technology is adopted to greatly change the crystal lattice of a prepared far infrared irradiating material. The frequency band of the material is narrow, the pertinence is strong, the radiance is high, the element toughness is greatly improved, the heat impact stability is good, and thus the material has a wide application prospect at a room temperature.

The present invention relates to a method and an apparatus for suppressing passive wireless earphones through a pulsed magnet field. According to the method, a continuous pulse wave with the pulse duty factor of 50%:50% and a continuous pulse wave with the pulse duty factor changing within the range from 75%:25% to 25%:75% are adopted, a magnetic field coil is directly driven by superposition of base wave pulses and high-order harmonic pulses, an auditory discrimination mode of human is simulated, and reception of passive wireless earphones is suppressed, so as to interfere and destroy information transmission paths and conditions of cheating-used earphones. Various interference pulse signals are generated by a single chip microcomputer, and power complementary pair transistors are directly driven, the technology and the method are mature, reliable and easy to operate, and audio language classrooms or laboratory site facilities can be directly utilized.

The invention provides a method for fitting the amplitude-frequency distribution of the space electric field of an airport omnidirectional beacon. Through the field test data and the method of mathematical statistics, the arc is fitted within the range of 108MHz to 117.975MHz of the omnidirectional beacon frequency band The amplitude-frequency characteristic curve of the space electric field can effectively reflect the relationship between the space electric field and the frequency of the modern electrified railway pantograph catenary offline arc. Draw the fitting curve of space electric field amplitude and frequency in the airport omni-directional beacon frequency band. According to the fitting curve, the interference problem between the amplitude and frequency of the space electric field caused by the pantograph-catenary off-line arc of the electrified railway can be solved.