123 results about "Crystal filter" patented technology

A reception circuit can receive a plurality of standard time signals and has a reception means for selectively receiving and demodulating any one of the plural standard time signals, and a control means for outputting a control signal that controls the reception means. The reception means includes a signal amplifier unit for amplifying a reception signal representing the received standard time signal; a signal extraction unit for extracting a signal of a specific frequency from the amplified reception signal; a rectifier unit for rectifying the extracted signal of the specific frequency; and a demodulation unit for demodulating the rectified signal of the specific frequency. The signal extraction unit includes a plurality of crystal filters corresponding to the frequencies of the plural standard time signals; a plurality of parallel capacitances corresponding to the plural crystal filters and parallel connected to the plural crystal filters; a filter switching unit for switching the plural crystal filters based on the control signal; and a parallel capacitance switching unit for switching the plural parallel capacitances based on the control signal. The control means outputs to the filter switching unit and the parallel capacitance switching unit a control signal denoting the switch states enabling the reception means to receive the standard time signal.

The invention, in various exemplary embodiments, incorporates a photonic crystal filter into an image sensor. The photonic crystal filter comprises a substrate and a plurality of pillars forming a photonic crystal structure over the substrate. The pillars are spaced apart from each other. Each pillar has a height and a horizontal cross sectional shape. A material with a different dielectric constant than the pillars is provided within the spacing between the pillars. The photonic crystal filter is configured to selectively permit particular wavelengths of electromagnetic radiation to pass through.

A crystal filter and a method of making a crystal filter capable of transmitting radiation within a particular pass band is disclosed. The crystal filter is particularly appropriate for a UV detection system, where the pass band is between about 200 to about 350 nm. A UV detection system incorporating the crystal filter is also described. One embodiment of crystal filter is formed from a single-crystal transparent host, such as a fluoride host, codoped with lanthanide or actinide fluorides and lanthanide or actinide nitrides, oxides, borides, carbides or hydroxides. Filter crystals according to the present invention can be grown by various crystal growth methods, including Czochralski and Bridgeman crystal growth methods.

A piezoelectric component comprises at least two stacked crystal filters on a substrate. Each stacked crystal filter comprises a bottom electrode, a first piezoelectric layer arranged above the bottom electrode, a central electrode arranged above the first piezoelectric layer, a second piezoelectric layer arranged above the central electrode, and a top electrode arranged above the second piezoelectric layer. The bottom electrodes are directly connected to one another and the central electrodes are directly connected to one another.

The invention discloses a phase type laser range finder and a phase detecting method thereof, belonging to the electronic measurement technical field. The phase type laser range finder comprises a signal sampling control module, a first signal amplifying filter module, a second signal amplifying filter module, a scale signal generation module, a laser modulation launching module, a light signal receiving detection module, a signal logarithmic converter, a power module and a display module. The phase detecting method comprises: selecting a system down sampling frequency, finding sampling data length, grouping sampling data, calculating phase shift and distance. The phase type laser range finder adopting the phase detection method can utilize a quartz crystal filter to filer the ranging signals, utilize continuous indirect scale frequency and down sampling technique, and combine sampling and signal processing functions on a chip, having simple structure, high measurement accuracy and low cost.

The invention discloses a high-linearity low-noise short wave broadband receiver which comprises a radio frequency input filter circuit, a radio frequency switch frequency-selecting assembly, a mode selecting circuit, an LC low-pass filter, a crystal oscillator amplifying circuit, a frequency synthesizer circuit, a frequency synthesizer driving circuit, a frequency mixer, a multistage crystal filter circuit and a multistage amplifying circuit. The radio frequency input filter circuit, the radio frequency switch frequency-selecting assembly and the mode selecting circuit are sequentially cascaded, an output of the mode selecting circuit is connected with the LC low-pass filter and then connected to the radio frequency input end of the frequency mixer. The crystal oscillator amplifying circuit, the frequency synthesizer circuit and the frequency synthesizer driving circuit are sequentially cascaded, and an output of the frequency synthesizer driving circuit is connected to the local oscillator input end of the frequency mixer. The intermediate frequency output of the frequency mixer is connected with the multistage amplifying circuit. The high-linearity low-noise short wave broadband receiver is high in scanning speed, high in linearity, low in noise and high in intermediate frequency and image frequency inhibition degree. An intermediate frequency output band is free of interference signal. The high-linearity low-noise short wave broadband receiver is suitable for broadband application and is low in power consumption.

The present invention provides a low-loss wideband terahertz wave gradient photonic crystal filter. The filter comprises a two-dimensional photonic crystal; different circular silicon dielectric columns are arranged periodically in a square lattice manner so as to form the two-dimensional photonic crystal; the middle of the two-dimensional photonic crystal is provided with a resonant cavity; the resonant cavity is composed of three dielectric columns; an input channel, an output channel and the resonant cavity are located on a horizontal line to form a terahertz wave transmission channel; the dielectric columns are evenly distributed at the upper side and lower side of the terahertz wave transmission channel and form a symmetrical structure; the sizes of the dielectric columns in the same row are identical; the radiuses of the dielectric columns are gradually increased from center to edge; and when terahertz waves arrives at the resonant cavity through the input channel, terahertz waves according with the resonant frequency of the resonant cavity are coupled into the resonant frequency, so that coupled output is obtained, and wideband filtering in the frequency range of 380GHz to 438GHz can be realized.

A crystal oscillator having a crystal filter with multiple crystals in a ladder configuration, resonant at a desired operating frequency. An oscillatory signal loop feedback path includes a voltage controlled phase shifter operable to shift the phase of the signal in the feedback loop in response to an applied control voltage. The feedback loop also includes a loop phase shift circuit to ensure that the feedback signal is a multiple of 360°, and a band pass mode selection circuit for eliminating unwanted frequencies.

The invention, in various exemplary embodiments, incorporates a photonic crystal filter into an image sensor. The photonic crystal filter comprises a substrate and a plurality of pillars forming a photonic crystal structure over the substrate. The pillars are spaced apart from each other. Each pillar has a height and a horizontal cross sectional shape. A material with a different dielectric constant than the pillars is provided within the spacing between the pillars. The photonic crystal filter is configured to selectively permit particular wavelengths of electromagnetic radiation to pass through.

The invention relates to a method for preparing medicinal sterile sodium bicarbonate raw powder, which comprises the following steps: (1) subjecting industrial sodium carbonate serving as a raw material to purification, dissolution in water, decarburization and membrane filtration; (2) introducing industrial carbon dioxide gas subjected to membrane treatment into solution of sterile sodium bicarbonate to carry out acidification, and controlling parameters such as flow rate, reaction time, terminal pH value and stirring speed; (3) adding ethanol liquid subjected to membrane treatment into solution in which reaction is finished to allow sodium bicarbonate crystals to precipitate gradually, adjusting stirring speed, and controlling crystallization time to allow the crystallization to be completed fully; and (4) filtering the solution by a crystal filter to obtain the product, and drying the product by using a vibratory drying machine to obtain a finished product that meets medicinal standards.

The present invention relates to a method for crystallizing the active layer of a thin film transistor utilizing crystal filtering technique. According to the conventional metal induced lateral crystallization (MILC) method, amorphous silicon layer can be crystallized into poly-crystal silicon layer. According the crystal filtering technique of the present invention, amorphous silicon layer can be single-crystallized by filtering a single crystal component from the poly-crystal region being crystallized by MILC. The TFT fabricated including an active layer crystallized according to the present method has significantly improved electrical characteristics such as electron mobility and leakage current as compared to the TFT including a poly-crystal silicon active layer made by conventional methods. The invention also provides various TFT fabrication methods applying the crystal filtering technique.

The invention relates to a radio frequency device laterally provided with a digital short wave receiver, and the radio frequency device can be used for a gateway of a sensor network. With working frequency range of 5MHz to 25MHz, the radio frequency device comprises a receiving aerial, a slicer circuit, a broadband frequency selection circuit, a receiving circuit and a local oscillation circuit, etc. The receiving circuit comprises a low noise amplifier, a first active frequency mixer, a surface acoustic wave filter, a second active frequency mixer, a crystal filter, a radio frequency amplifier, a third active frequency mixer, an active band-pass filter and an AGC circuit, etc. The three-time frequency conversion superheterodyne structure design is adopted, and a first intermediate frequency is 240MHz to 250MHz, a second intermediate frequency is 35MHz to 45MHz, and a third intermediate frequency is 10MHz to 20MHz. The radio frequency device is a novel radio frequency device for a blind sending and blind receiving unidirectional oversea communication gateway, the volume of the radio frequency is less than that of a half of a cell phone; the radio frequency device is applicable to digital short wave remote communication adopting modulation methods of 4FTSK, BPSK and QPSK, and can receive the message in a multi-frequency point and multi-mode frequency sweeping way within the scheduled time, thus realizing the function of multi-frequency point repeating burst communication.

The invention provides an alternating current induced magnetic field sensor with a measuring frequency scanning function. The alternating current induced magnetic field sensor with the measuring frequency scanning function is characterized in that a frequency adjustable multi-passage signal generator, a first transducer, a crystal filter, a second transducer, a band-pass filter, a phase-sensitive detector, a low pass filter, a low-noise amplifier, an excitation magnetic field coil and a probe are included, the probe, the first transducer, the second transducer, the phase-sensitive detector and the excitation magnetic coil are connected with the frequency adjustable multi-passage signal generator respectively, and the probe, the first transducer, the crystal filter, the second transducer, the band-pass filter, the phase-sensitive detector, the low pass filter and the low noise amplifier are sequentially connected with one another. The alternating current induced magnetic field sensor has the advantages of being capable of scanning an alternating current frequency sensing magnetic field and effectively filtering noise and disturbance.

A composite band-pass filter receives a quadrature input signal and passes an intermediate frequency signal while attenuating all other signals including an undesired image signal. The composite band-pass filter is comprised of a continuous time polyphase filter and a discrete time polyphase filter and can amplify signals. The amplification is distributed through out the composite band-pass filter and the amount of amplification may be selected by control signals. The composite band-pass filter has improved dynamic range and noise characteristics, selectable amplification and replaces an external crystal filter.

The invention is a wavelength division and mode division hybrid multiplexer based on photonic crystal and nanowire waveguide. A two-dimensional triangular lattice photonic crystal filter (1) is an air-hole photonic crystal plate structure periodically distributed along an X-Y plane, and uses silicon as a host material. An L3-type resonant cavity (2) is formed by removing three air holes. Narrow waveguide structural regions I and II are formed by integrally translating the air holes on a side of the photonic crystal waveguide. A nanowire mode division multiplexer (5) uses silicon as a host material, uses silicon dioxide as a substrate material, and uses asymmetrical directional coupling structure. By using the coupling effect of the microcavity and the waveguide, a download filtering function for a specific-frequency light wave is realized. On this basis, in combination with the nanowire waveguide mode division multiplexing structure, a hybrid multiplexing structure is formed. The wavelength division and mode division hybrid multiplexer can be further cascaded and expanded, can be applied to a C + L band coarse wavelength division (channel spacing of 20 nm) multi-mode (>2) multiplexing system.

The invention discloses a method for mineralization storage of CO2 through magnesium resources in serpentine, and belongs to the fields of mines, metallurgy, chemical industry and environments. The serpentine is subjected to Mg leaching, and the CO2 is subjected to mineralization storage through the serpentine and leached Mg. The method comprises the steps: the pretreated serpentine and sulfuric acid are subjected to crossflow leaching, and a filtered leaching solution is crystallized to obtain magnesium sulfate heptahydrate; the solution after crystal filtering returns into a first-time serpentine leaching reaction system; then magnesium sulfate heptahydrate crystals are dissolved in water, serpentine powder is added, the CO2 gas is introduced, and a magnesium bicarbonate solution is prepared; then the magnesium bicarbonate solution is heated to obtain magnesium carbonate; and finally, mineralization storage of the magnesium to the greenhouse gas and enrichment of metal nickel and iron are achieved.

The invention discloses a low-noise crystal oscillator based on multiple resonators, and mainly solves the problems that an existing crystal oscillator reduces background phase noise of oscillator output signals, product debugging difficulty is increased, and batch production is not facilitated. The crystal oscillator comprises a filter circuit connected with an external voltage-stabilizing powersupply; a transistor amplifier, wherein the collector electrode of the transistor amplifier is connected with the power supply circuit; a main vibration frequency selection loop and a feedback capacitor which are connected with a base electrode of the transistor amplifier; a crystal frequency selection feedback circuit which is connected with the feedback capacitor; an LC parallel resonance network which is connected with the main vibration circuit and the feedback capacitor; and a crystal filter circuit which is connected with the transistor amplifier. According to the invention, the circuitfrequency selection characteristic and the circuit on-load Q value can be effectively improved, the phase noise of the near-load frequency band of the oscillation signal is reduced, the high-Q crystalfrequency selection feedback circuit is arranged at the output of the main oscillation emitter, the narrow-band frequency selection characteristic of the crystal resonator is fully utilized, and thesignal phase noise index of the far-load frequency band is improved.

A reception circuit can receive a plurality of standard time signals and has a reception means for selectively receiving and demodulating any one of the plural standard time signals, and a control means for outputting a control signal that controls the reception means. The reception means includes a signal amplifier unit for amplifying a reception signal representing the received standard time signal; a signal extraction unit for extracting a signal of a specific frequency from the amplified reception signal; a rectifier unit for rectifying the extracted signal of the specific frequency; and a demodulation unit for demodulating the rectified signal of the specific frequency. The signal extraction unit includes a plurality of crystal filters corresponding to the frequencies of the plural standard time signals; a plurality of parallel capacitances corresponding to the plural crystal filters and parallel connected to the plural crystal filters; a filter switching unit for switching the plural crystal filters based on the control signal; and a parallel capacitance switching unit for switching the plural parallel capacitances based on the control signal. The control means outputs to the filter switching unit and the parallel capacitance switching unit a control signal denoting the switch states enabling the reception means to receive the standard time signal.

A V-groove is formed in a platform of single crystal silicon by anisotropic wet etching based on its crystal orientation, and a convexity of an optical element chip is fitted in an intermediate portion of the V-groove. Quadrangular frustoidal convexities are formed in rows and columns on a single crystal silicon wafer by anisotropic wet etching, then a photonic crystal filter element is formed as an optical element on the protruding end face of each convexity, and the wafer is cut for each optical element into individual optical element chips. When optical fibers are disposed in the V-groove at both sides of the chip, cores of the optical fibers and light inlet and outlet ports of the optical element are aligned with each other.

The invention relates to a preparation method of a natamycin laminar crystal, and the preparation method comprises the following steps: (1) adding natamycin mycelium into a methanol and water mixed liquid, wherein the volume ratio of methanol to water is (60-90):(40-10); (2) adjusting the pH value to 10-12 with a basic substance; (3) carrying out liquid-solid separation and collecting filtrate to obtain a natamycin extract; (4) concentrating the extract until the content of natamycin is 18-26 mg / mL, and flocculating to remove insoluble substances to obtain a natamycin fine extract; (5) acidifying the natamycin fine extract by two stages: firstly dripping acid slowly until the pH value decreases to 8-9, then stirring for more than 1 hour, then slowly dripping the acid until the pH value decreases to 6-7, and then stirring for more than 3 hours to obtain a crystallization liquid of the laminar natamycin crystal; and (6) carrying out liquid-solid separation and drying in vacuum to obtain the laminar natamycin crystal. By adoption of the preparation method provided by the invention, the uniform natamycin laminar crystal can be prepared, the subsequent crystal washing and drying difficulties are reduced, and the crystal filtering and drying time is shortened.

The invention provides an alternating current magnetic field sensor with a measuring frequency scanning function. The alternating current magnetic field sensor with the measuring frequency scanning function comprises a frequency adjustable multi-passage signal generator (1), a first transducer (2), a crystal filter (5), a second transducer (6), a low pass filter (7), a low-noise amplifier (8) and a probe. The probe, the first transducer (4) and the second transducer (6) are respectively connected with the frequency adjustable multi-passage signal generator (1). The probe, the first transducer (4), the crystal filter (5), the second transducer (6), the low pass filter (7), and the low noise amplifier (8) are sequentially connected with one another. The alternating current magnetic field sensor has the advantages of being capable of scanning an alternating current frequency sensing magnetic field and effectively filtering noise and disturbance.

The invention discloses a VDES radio frequency front-end detection system for ships. A power divider module is used for dividing a radio frequency signal into five independent radio frequency paths, and outputting the five independent radio frequency channels to crystal filters on channel board modules corresponding to respective channels to form a radio frequency signal in an independent frequency band; and a power detection module is used for detecting and recognizing the radio frequency signal. The power detection module detects a signal in-band power maximum value, outputs a control signalaccording to the power maximum value to control a first radio frequency switch to select a radio frequency path, selects a radio frequency direct path or an amplification path, outputs a signal to asecond filter, and enters an analog to digital (AD) conversion module to perform AD conversion. Through design of five independent radio frequency paths, radio frequency signals can be received and processed simultaneously. The independent crystal filters are used for filtering each independent frequency point, thereby achieving high signal selectivity.

A superlattice crystal resonator having a substrate of a dielectric acoustic superlattice material, both sides of which substrate are plated with electrodes. The resonator can be a one-port resonator if the electrode on both sides is a single electrode, or it can be a two-port resonator if the electrode on one side is a single electrode and the electrode on the other side is a bipolar electrode. The superlattice crystal resonator can be used as a superlattice crystal filter, either in the form of a monolithic superlattice crystal filter formed by a two-port superlattice crystal filter, or in the form of a combined superlattice crystal filter where a number of one-port superlattice crystal resonators are interconnected in various circuitry configurations with or without other electronic components, such as capacitors, inductors, and resisters.

The invention relates to a crystal filter for a wet-process phosphoric acid concentrating device. The crystal filter for the wet-process phosphoric acid concentrating device comprises a barrel, and a cylindrical filter core arranged in the barrel, wherein an annular channel is formed between the cylindrical lateral wall of the filter core and the lateral wall of the barrel; the top part of the filter core forms a taper; the taper top part of the filter core and the lateral wall are provided with filter holes with the apertures of 25-55mm; a liquid outlet led to the outside of the barrel is arranged at the bottom part of the filter core; the barrel is provided with a liquid inlet above the taper top part of the filter core; the bottom wall of the inner cavity of the barrel is tipsily arranged, and a bleed hole is arranged at the bottom part of the barrel. By filtering strong phosphoric acid concentrated in a flash chamber, a graphite pipe can be effectively prevented from being blocked, and the service life of a graphite heat exchanger is prolonged.

The invention relates to a recycling method for aluminum in an aluminum alloy chemical milling waste liquid, and belongs to the technical fields of recovery and recycling of aluminum alloy alkaline chemical milling waste liquids. The method specially comprises the following steps: 1) performing separation treatment: performing centrifugation on the aluminum-containing alloy chemical milling wasteliquid, and removing a precipitate in the waste liquid; 2) under normal temperature and normal pressure, adding hydrogen peroxide into the precipitate-removed waste liquid, and performing a full reaction to obtain a reaction mixture; and 3) performing solid-liquid separation on the reaction mixture to obtain a AlOOH crystal filter cake and a filtrate; and washing the AlOOH crystal filter cake by using water, and performing drying to prepare nano AlOOH. The method provided by the invention has a short production process, small demand for equipment and a fast reaction speed; the recovery rate ofaluminum resources in the chemical milling waste liquid is up to 83%; the prepared product is the orthorhombic AlOOH with a particle size of 50-200 nm, and has a nano structure and the advantages ofa large specific surface area and high purity; and the method facilitates industrial production and applications of medicines, catalysts, adsorbents, ceramics and fireproof materials.

The invention discloses a comprehensive purification fresh air system with a mite killing function for indoor air, and belongs to the field of fresh air systems. The comprehensive purification fresh air system solves the problem that in the prior art, no comprehensive purification system is used for removing formaldehyde and TVOC to improve the environment quality. The comprehensive purification fresh air system with a mite killing function for indoor air comprises a box body, wherein two circular air inlets are formed in one end of the box body, and two circular air outlets are formed in theother end of the box body; air inlet fans are installed in the air inlets; a filtering system is arranged in the box body, and comprises a roller conveying filter screen, a V-shaped dense-pleated HEPAfilter, a nano-ore crystal filter cartridge, a solid fragrance box, a photocatalyst catalysis plate, a dehumidification plate and a bamboo charcoal adsorption plate which are arranged in sequence inthe movement direction of air flow; and an ultraviolet lamp is inlaid in the center of the dehumidification plate, and the ultraviolet lamp is connected with a ballast. Through the transformation of the comprehensive purification fresh air system, comprehensive filtering of a new decoration site is completed, and the convenient and efficient comprehensive purification fresh air system for the indoor air is created.