122 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.

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 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, 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 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, 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 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 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 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.

To provide an oscillation module which is able to improve an input level by passing signals in a main signal band while removing near noise and far noise.An oscillation module is provided with an OCXO, an amplifier, and a noise elimination filter. The noise elimination filter includes: a BPF passing a signal in the main signal band and eliminating far noise with respect to the main signal band; an L-BEF eliminating near noise in a low frequency band with respect to the main signal band; and an H-BEF eliminating near noise in a high frequency band with respect to the main signal band. Each filter is configured with a crystal filter.

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.