12results about How to "High spectral purity" patented technology

The invention discloses a lunar exploration cubesat measurement and control responder system and a transmitting signal coherent carrier generation method thereof, and the system comprises a frequency mixer, a receiving local oscillator phase-locked loop, an intermediate frequency sampling analog-to-digital converter, a voltage-controlled oscillator, a digital-to-analog converter, a transmitting local oscillator phase-locked loop and a carrier tracking loop. Wherein the frequency mixer generates an intermediate-frequency signal according to radio frequency input and a local oscillation signal, the intermediate-frequency signal is output to the intermediate-frequency sampling analog-to-digital converter after band-pass filtering, and the intermediate-frequency sampling analog-to-digital converter outputs the intermediate-frequency signal to the carrier tracking loop after the intermediate-frequency signal is subjected to down-conversion processing of an X-band radio frequency signal; the carrier tracking loop outputs a digital signal to the digital-to-analog converter to generate an analog voltage for controlling the voltage-controlled oscillator; the voltage-controlled oscillator controls the output frequency through the voltage of the digital-to-analog converter; receiving a reference signal output by the local oscillator phase-locked loop according to the voltage-controlled crystal oscillator, performing phase-locked frequency multiplication processing and generating a local oscillator signal; and the transmitting local oscillator phase-locked loop performs phase-locked frequency multiplication processing on the reference signal. According to the invention, in an analog-digital combination mode, a digital frequency-locked phase-locked loop is used for controlling the output voltage of a DAC to control the frequency of a reference VCXO, so that carrier tracking of a radio frequency-intermediate frequency-digital large loop closed loop is completed; downlink coherent carriers can be directly obtained by PLL (Phase Locked Loop), and the requirement of downlink / uplink forwarding ratio 880 / 749 is strictly met.

The invention relates to the technical field of optical fiber lasers, and proposes an ultra-wideband tunable optical fiber communication light source based on gas stimulated Raman scattering, comprising a 1μm band seed source, an electro-optic modulator, a signal generator, an optical fiber amplifier, a solid-hollow compact coupling device, an optical fiber end cap, a hollow-core optical fiber, a micro gas cavity, a lens, a dichroic mirror, and a methane gas 1μm band tunable pump source. The tuning range covers at least 1024nm-1126nm. Based on the stimulated Raman scattering effect of methane gas, it can be converted into a communication band laser covering the entire S+C+L+U band. Thanks to the Raman characteristics of methane molecules, the output laser has a corresponding narrow line width single spectral line under single wavelength pumping, without accompanying ASE noise amplification, etc., and does not need to be selected through secondary filtering. At the same time, the use of the hollow-core optical fiber ensures that the output laser is only single-mode, and high beam quality can be guaranteed without other operations.

The embodiment of the present application discloses a frequency synthesis circuit and method, the circuit comprises: a power divider, the input end of the power divider is connected with a reference clock signal, for distributing the reference clock signal into multiple sub-reference signals, and outputting the multiple sub-reference signals through the corresponding output end of the power divider; wherein the multiple sub-reference signals are consistent in phase and equal in power; multiple phase-locked frequency multiplication channels, the input end of each phase-locked frequency multiplication channel is connected with the output end of the power divider correspondingly, and the phase-locked frequency multiplication channel is used for generating a first frequency signal after phase-locked frequency multiplication processing according to the corresponding sub-reference signal; a synthesis control module, the input end of the synthesis control module is connected with the output end of the multiple phase-locked frequency multiplication channels, and the synthesis control module is used for synthesizing the multiple first frequency signals to generate a final output signal. The technical scheme of the embodiment of the present application generates signals with the same frequency and phase correlation through the multiple phase-locked frequency multiplication channels, and improves the spectral purity of the signals.

The invention provides a manufacturing method of a resonant cavity light-emitting diode, which comprises the following steps of: performing epitaxial manufacturing on a first type semiconductor layer in a window with a smaller area, so that the crystal quality is improved, and the reliability of a device is improved; an active layer, a second-type semiconductor layer and a first reflecting layer are sequentially manufactured in an epitaxial mode and inversely arranged on the bearing substrate, the area of the first-type semiconductor layer is gradually reduced in the direction away from the bearing substrate, a second reflecting layer is manufactured on the inclined wall of the first-type semiconductor layer, and the first reflecting layer and the second reflecting layer form a resonant cavity; light is reflected for multiple times in the resonant cavity, so that the light resonance effect is improved, the light has a narrower wavelength peak, and the spectral purity is improved; the upper surface, far away from the bearing substrate, of the first type semiconductor layer is a light outlet, the area of the light outlet is the smallest, and the directivity and collimation of light emitting can be improved.

The present invention discloses a beacon machine for telemetry fly ball training, including a power supply, the power supply is connected to a wide voltage circuit regulator, the wide voltage circuit regulator is connected to a first low voltage difference regulator and a second low voltage difference regulator, the first low voltage difference regulator is connected to a controller, the input end of the controller is connected to a power frequency communication serial port, the output end is connected to a variable frequency phase lock, the variable frequency phase lock is connected to an antenna for transmitting signals, the output end of the second low voltage difference regulator is respectively connected to the variable frequency phase lock and a crystal oscillator, and the crystal oscillator is connected to the variable frequency phase lock. The telemetry fly ball training beacon machine of the present application is a miniaturized, high-performance broadband, stable beacon machine module with programmable power frequency. It has high phase noise and spurious suppression characteristics, which helps to improve the spectrum purity of the transmitter to improve the sensitivity test accuracy of the receiver; at the same time, it also has high frequency stability and accuracy, as well as ultra-low phase noise characteristics.

The present application relates to the field of microwave photonics, and more particularly to a high linearity microwave photonics down-conversion receiving system based on an optoelectronic oscillator. The system comprises a laser, a first phase modulator, a first optical amplifier, a phase-shifted Bragg grating, a first photodetector, a second phase modulator, an optical filter, a second optical amplifier, and a second photodetector. The frequency of the local oscillator signal generated by the first photodetector can be tuned by changing the frequency of the laser, thereby effectively realizing the tuning of the down-converted signal output by the second photodetector. By adjusting the gain value of the first optical amplifier, the amplitude of the local oscillator spectral harmonic in the output optical signal of the first phase modulator is a specific value, thereby realizing the suppression of the third-order intermodulation distortion in the output signal, and further improving the spurious-free dynamic range of the entire down-conversion receiving system. The system has reconfigurability and high linearity, and can play a technical value in the field of radar and communication applications.

The application discloses a control method, a storage medium and a terminal based on a Brillouin laser Kerr optical frequency comb of an orthogonal polarization mode, and is based on a control module; the method comprises the following steps: an initial control step; a secondary pumping control step: a second control command is sent to an adjustable wavelength laser, and based on monitoring data of a fourth optical detector used for monitoring a state of a stimulated Brillouin laser of a cross-polarization TM mode after polarization beam splitting of light, a pumping laser wavelength blue shift speed and an optical power are further adjusted until a Kerr optical frequency comb state appears. The application generates a stimulated Brillouin laser of an orthogonal polarization mode to form a Kerr optical frequency comb through secondary pumping, filters specific comb tooth interval light waves of the optical frequency comb, performs beat frequency on the filtered light wave signals, and obtains a required microwave signal output.

This invention proposes a narrow-emission ultraviolet gallium sulfide quantum dot material and its synthesis method, belonging to the field of semiconductor quantum dot material technology. The method employs a one-pot synthesis strategy and introduces a specific passivating agent into the reaction system. By precisely controlling the reaction conditions and the amount of passivating agent, high-purity ultraviolet-emitting gallium sulfide quantum dots with an emission peak at 392 nm and a half-maximum width at half-maximum (HWHM) of 34 nm were successfully prepared. This synthesis method significantly reduces the HWHM of gallium sulfide quantum dots and improves their spectral purity. This invention provides an effective method for preparing ultraviolet environmentally friendly quantum dots with high color purity, demonstrating great application potential in cutting-edge fields such as lighting and full-color displays.

The utility model discloses a frequency hopping frequency source module based on DDS relates to microwave radio communication technical field, including crystal oscillator, power divider and frequency mixer, and power divider and frequency mixer are connected in parallel through first branch and second branch, and first branch includes FPGA chip, PLL chip, DDS chip and first filter who connects in order series connection, and FPGA chip and power divider first output electric connection, and first filter and frequency mixer first input electric connection, and the second output of FPGA chip and the frequency control input of DDS chip electric connection. The utility model discloses the hardware construction under relevant layout, still makes it have the advantage that the output frequency coverage is wide under the original already having the advantage that the frequency switching speed is fast, and the frequency resolution is high.

The invention provides a low-jitter ultra-wideband pulse signal generator and a pulse signal generation method.The low-jitter ultra-wideband pulse signal generator comprises a crystal oscillator, a power divider, a local oscillator signal path, an intermediate frequency signal path and a wideband mixer, the power divider is used for dividing a reference frequency signal into two paths and respectively sending the two paths to a local oscillator signal path and an intermediate frequency signal path, an absorption type band-pass filter in the local oscillator signal path is used for outputting a local oscillator signal of a target frequency, and an absorption type high-pass filter in the intermediate frequency signal path is used for outputting an ultra-wideband intermediate frequency signal; the broadband mixer is used for mixing the local oscillator signal and the intermediate frequency signal to output an ultra-wideband pulse signal with the center frequency as the target frequency, and it is ensured that the output signal has the low jitter characteristic and the high signal-to-noise ratio.

The application discloses an injection locking frequency multiplication device, a phase-locked loop and a method, which integrates a digitalized capacitance array in a resonant cavity of an injection locking frequency multiplier, and combines a frequency multiplication amplitude detection module and a feedback control module to form a closed-loop adaptive tuning structure, so that the equivalent capacitance and the resonant frequency of the resonant cavity can be adjusted in real time according to the amplitude change of a frequency multiplication signal, thereby effectively compensating for frequency drift caused by process deviation, power voltage fluctuation and temperature change, significantly widening the working frequency band of the injection locking frequency multiplier, improving locking accuracy and working stability, avoiding the phase noise deterioration and power consumption increase phenomenon caused by reducing the Q value of the resonant cavity or increasing the injection power to widen the locking range in the traditional scheme, enabling the frequency multiplier to realize wide frequency working and automatic calibration while maintaining good spectral purity and low phase noise, and being more suitable for a phase-locked loop and a radio frequency front-end circuit in a multi-frequency band and wideband communication system.

The invention discloses preparation of a Cr < 3 + >-doped fluorescent material and application of the Cr < 3 + >-doped fluorescent material in a plant light supplement lamp, and relates to the technical field of preparation of Cr < 3 + >-doped fluorescent materials.The preparation method comprises the following steps that a matrix raw material and a Cr < 3 + >-containing raw material are weighed according to the stoichiometric ratio, and the matrix raw material and the Cr < 3 + >-containing raw material are ground and stored in a dryer; putting the raw materials into a ball milling tank, and carrying out planetary ball milling for 3-6 hours; transferring to an alumina crucible, and pre-sintering for 2-5 hours; after secondary ball milling, adding a fluxing agent; sintering in a high-temperature furnace for 6-10 hours, and cooling along with the furnace or under the protection of inert gas; the preparation method comprises the following steps: coarsely crushing, grinding to 10-30 microns, alternately cleaning with deionized water and ethanol, drying in an air dry oven, detecting and screening by using a fluorescence spectrophotometer, an X-ray diffractometer and a scanning electron microscope, and remanufacturing unqualified products after adjusting process parameters according to detection results. The light-emitting efficiency is high, the spectrum adapts to plant photosynthetic absorption, the plant growth can be promoted when the light-supplementing lamp is applied, the plant height and the chlorophyll content are obviously increased, the natural spectrum is simulated, and the light-supplementing lamp is suitable for multiple cultivation scenes.