301 results about "Microwave frequency" patented technology

The invention relates to the technical field of atomic clock control, and discloses a punctuality type atomic clock control method based on a microwave frequency band. The method comprises the following steps: firstly, acquiring microwave frequency band signal data and atomic state data, and constructing a time calculation model in combination with historical operation data to output a theoretical time value; performing multi-dimensional difference analysis on the theoretical time value and the actual measurement time value to generate a time difference coefficient matrix; inputting the matrix into a spatial propagation analysis network, and combining atomic clock component parameters and environmental parameters to generate a time anomaly probability distribution diagram; and finally, configuring microwave control parameters according to the distribution diagram, including starting a high-frequency monitoring mode for a high-probability abnormal region and applying a disturbance test to adjacent frequency bands. According to the method, through multi-dimensional data modeling, difference analysis and dynamic parameter configuration, the accuracy and adaptability of atomic clock control are improved, and the operation stability of the atomic clock in a complex environment can be enhanced.

The invention provides an active regulation and control device for a microwave resonant cavity based on Rydberg atoms. The microwave resonant cavity comprises a protective shell, an atomic gas chamber and a photoelectric detector, the active regulation and control device comprises a PID control module and piezoelectric ceramics, the PID control module is used for processing a received EIT transmission spectrum signal after generating a modulation signal to carry out atomic resonant frequency scanning on the atomic gas chamber, obtaining a target resonant frequency through a current feedback zero crossing point corresponding to an EIT transmission spectrum valley bottom value, and generating a deviation correction signal; and the piezoelectric ceramic is used for adjusting the length of a protective shell of the microwave resonant cavity according to the received correction signal, so that the atomic resonant frequency is locked as the target resonant frequency. The invention further provides an active regulation and control method for the microwave resonant cavity based on the Rydberg atoms. According to the invention, the resonant frequency of the microwave resonant cavity can be rectified in real time, and the optimal and most stable resonant mode of the local oscillation microwave frequency responding to atoms is kept.

The invention provides a microwave superheterodyne frequency sweep measurement system based on Rydberg atoms, and belongs to the technical field of microwave frequency measurement. The laser module excites detection light of 780 nm and coupling light of 480 nm, and the two beams of light are reversely input into the atomic gas chamber through the dichroscope; signal microwaves are generated by a radio frequency signal source and are radiated to the position of the atomic gas chamber through the horn antenna; local oscillation microwaves are generated by the microwave module and are also radiated to the position of the atomic gas chamber through the horn antenna; the atomic gas chamber serves as a mixer to form a difference frequency signal; the spectrum analyzer is used for monitoring low-frequency difference frequency signals generated in the frequency mixing process in real time and recording signal intensity in real time. According to the invention, high-precision and wide-band microwave frequency measurement is realized, continuous and smooth frequency sweeping response can be provided in a frequency range, and absolute frequency detection of microwave signals is realized under the condition that a complex frequency comb technology is not introduced. The hardware architecture is simplified, the automation degree is improved, and integration, popularization and application are facilitated.

An unidentified aerial phenomena field disturbance detector includes an accelerometer configured to measure a gravitational field surrounding the unidentified aerial phenomena field disturbance detector; a magnetometer configured to measure a magnetic field surrounding the unidentified aerial phenomena field disturbance detector; a microwave frequency detector configured to measure a specific band of microwave frequencies surrounding the unidentified aerial phenomena field disturbance detector; a controller; and an optical indicator configured to optically communicate information to a user of the unidentified aerial phenomena field disturbance detector. The controller determines a change in the gravitational field surrounding the unidentified aerial phenomena field disturbance detector when generates gravitational field values are outside a predetermined range of non-event field values. The controller controls the optical indicator to optically communicate the determined change in the gravitational field surrounding the unidentified aerial phenomena field disturbance detector.

The invention discloses a quantum magnetometer device based on a diamond nitrogen-vacancy color center. The quantum magnetometer device comprises a laser emission unit used for generating a 532nm laser beam based on a laser trigger signal; the beam shaping unit is used for focusing the laser beam to the diamond sample; the diamond sample comprises an NV color center array with specific depth on the surface or in the diamond sample, and electrons in NV color centers are excited based on laser beams to transition and generate fluorescence; the fluorescence collection unit is used for separating exciting light from 650-800nm fluorescence signals and converting the fluorescence signals into multi-channel electric signals; the microwave radiation unit is distributed around a diamond sample space and emits three independently regulated microwave frequencies at the same time; and the control and processing unit is used for receiving and processing the multi-channel electric signals in real time and analyzing magnetic field parameters based on the optical detection magnetic resonance spectral line. Synchronous measurement of a three-dimensional magnetic field is realized, and the limitation of single-axis measurement of a traditional NV magnetometer is broken through.

The invention discloses a diamond low-frequency current measurement method with nonlinear response to magnetic field intensity, which is characterized in that two coils are wound on a magnetic flux collector with a communicated structure, a high-frequency (800Hz) high-voltage (7V) driving current is injected into one of the coils, a magnetic field generated by the coil is amplified through the magnetic flux collector and guided to an area where an NV color center magnetometer is located, and the NV color center magnetometer is located; and the signal is driven to enter a nonlinear response interval in the demodulated ODMR spectrum. A weak (1-50mV) to-be-measured low-frequency (0.1-10Hz) current signal is injected into the other coil, amplitude modulation is performed on the weak (1-50mV) to-be-measured low-frequency (0.1-10Hz) current signal by using the same frequency as the driving current, and the weak (1-50mV) to-be-measured low-frequency (0.1-10Hz) current signal is amplified by the magnetic flux collector and guided to the NV The microwave frequency is locked at the maximum slope point of the ODMR frequency spectrum through CW-ODMR phase-locked amplification, so that the relationship between the change of the red fluorescence signal intensity and the size of the external magnetic field is obtained, and the signal intensity of the low-frequency current magnetic field to be measured is measured according to the relationship.

The invention discloses a resonant frequency tracking control method and system for a diamond nitrogen vacancy color center, and belongs to the technical field of quantum sensing. The method comprises the following steps: setting an initial center frequency output by a microwave source; in the tracking control process, fluorescence signal changes generated by the diamond nitrogen vacancy color center under the microwave frequency modulation effect are recorded, a full-amplitude demodulation amplitude value R is obtained through demodulation, and whether the full-amplitude demodulation amplitude value R is smaller than a dead zone threshold value or not is judged; if yes, the center frequency output by the microwave source is not changed; if not, calculating the microwave frequency regulation quantity delta f according to the full-amplitude demodulation amplitude R; determining the adjusting direction of the center frequency f0 of the microwave source according to the phase-frequency characteristic and the real-time demodulation phase difference delta phi in the current frequency tracking control process; according to the microwave frequency adjusting quantity delta f and the adjusting direction, the center frequency of the microwave source is adjusted for resonant frequency tracking; wherein the phase-frequency characteristic is the characteristic of the demodulation spectral line on the two sides of the resonant frequency. The robustness and the accuracy of the resonance frequency tracking method are enhanced.

The invention relates to the technical field of defect detection, in particular to a defect detection method and system based on a microwave frequency crystal resonator, and the method comprises the steps: forming a microwave probe through a microwave frequency crystal resonator array, placing a to-be-detected material below the microwave probe, and setting a scanning area and scanning step lengths in two directions on the surface of the material; controlling the probe to perform point-by-point scanning according to step length, and collecting a plurality of reflection coefficients of each sampling point to form an echo signal matrix; performing singular value decomposition on the matrix, applying an adjustable coefficient to a first singular value and a second singular value, and adaptively selecting an optimal coefficient according to imaging quality to reconstruct an echo signal; performing two-dimensional Fourier transform on the reconstructed matrix, constructing a spatial filter in combination with probe spacing and defect depth to perform phase compensation, performing two-dimensional Fourier transform to obtain a defect image, and performing threshold segmentation on the defect image to obtain a binary image only containing defects; and analyzing the connected regions to obtain the gravity center position of each defect and the defect area determined by the pixel number and the single pixel area. The problems of serious clutter interference, insufficient defect imaging contrast ratio, difficulty in quantitative evaluation of defect size and the like in the existing microwave detection can be solved.

A diamond magneto-optical sensor includes: a diamond that includes a color center with an electronic spin and is irradiated with excitation light, and an irradiation unit that irradiates the diamond with the excitation light of the color center and electromagnetic waves for magnetic resonance, wherein the irradiation unit receives modulated light having been subjected to amplitude modulation, and a modulation frequency of the modulated light is included in a microwave frequency band.

The invention provides an electric field measuring device for continuously tunable microwave frequency based on Rydberg atoms. The electric field measuring device comprises a reflecting mirror, an atom steam pool, a first electrode plate, a second electrode plate, a dichroscope, a photoelectric detector and a data receiving module, the detection laser passing through the reflector and the coupling laser passing through the dichroscope oppositely hit into the atom steam pool to coincide, and a transmitted optical signal enters the photoelectric detector after hit into the atom steam pool; the photoelectric detector is electrically connected with the data receiving module; the first electrode plate and the second electrode plate are externally arranged above and below the atomic steam pool respectively; the first electrode plate and the second electrode plate are used for applying an alternating current electric field acting on the atomic steam pool, and different AC Stark frequency shifts are generated by controlling the electric field intensity of the alternating current electric field, so that high-sensitivity measurement of the continuous tunable microwave frequency electric field is realized. According to the invention, high-sensitivity measurement of the continuous tunable microwave frequency electric field can be realized, and the accuracy of a measurement result is ensured.

The present invention relates to a spacecraft electric thruster particularly suitable for both propellant-fed and air-breathing electric space propulsion comprising an ionization chamber (11) for plasma generation which develops along a central development axis (X), wherein the ionization chamber (11) has a chamber inlet (12) configured to allow gas inflow and a chamber outlet (13) configured to allow extraction of ionized gas particles; a power injection assembly (30) configured to perform electron heating for plasma generation inside the ionization chamber (11); a magnetic assembly (20) configured to generate a magnetic field for plasma confinement in the ionization chamber (11); and an ion extraction and acceleration assembly (40) configured to extract ionized gas particles from the ionization chamber (11) through the chamber outlet (13) and accelerate them along an ion acceleration direction (Z), wherein the power injection assembly (30) comprises a microwave power delivery system (31) configured to deliver an electric field oscillating at a selected microwave frequency (f) and to inject the generated oscillating electric field in the ionization chamber (11), and wherein the ionization chamber (11) comprises a plurality of walls (11a, 15,16,41) closed to the passage of microwaves apart from a portion of at least one lateral wall (11a) of the plurality of walls (11a, 15,16,41) at which the power delivery system (31) is coupled to inject the generated oscillating electric field in the ionization chamber (11), and is resonant for electromagnetic fields oscillating at the selected microwave frequency.

A method of detecting an increase in gas content in a pipe. The method includes flowing fluid through the pipe. The method includes generating, by a network analyzer, microwaves data representing a complex scattering coefficient over a first spectrum of microwave frequencies that are emitted through a waveguide and a fluid within the pipe and determining a statistical profile of a complex scattering magnitude over a second spectrum of microwave frequencies. The method includes determining that an amount of gas within the pipe satisfies a threshold amount and causing a flow of fluids within the pipe to slow or stop until the amount of gas falls below a predetermined threshold value.

The invention relates to a current measurement method, electronic equipment and a readable storage medium. The method comprises the following steps: acquiring an initial resonant frequency of the quantum current sensor, and outputting a microwave modulation signal according to the initial resonant frequency; performing optical detection magnetic resonance measurement operation based on the microwave modulation signal, obtaining a measurement response signal for the microwave modulation signal, and demodulating the measurement response signal to obtain a demodulation component; when the demodulation component is not matched with the demodulation component target value, the PID parameter is adjusted, and the microwave frequency of the microwave modulation signal is adjusted based on the adjusted PID parameter until the demodulation component is matched with the demodulation component target value; a microwave frequency when the demodulation component matches the demodulation component target value is determined as a microwave resonance frequency, and a current measurement value is determined on the basis of the microwave resonance frequency. By adopting the method, the current measurement efficiency of the quantum current sensor can be improved.

The invention belongs to the field of microwave wireless power transmission, and discloses a transparent linear circular polarization converter applied to microwave wireless energy transmission, which is composed of five layers of structures: a first layer is a cross patch with an inclined angle of 45 degrees, a cross recess is formed in the middle of the cross patch, and the whole body is composed of a cell with the external size of 1 * 1mm and the internal size of 0.95 * 0.95 mm; the wire width of all the copper wires is 0.05 mm; the second layer is a square substrate pet, the dielectric constant is 3.5, and the dielectric loss angle tangent is 0.03; the third layer is formed by splicing four isosceles right triangles, and the length of the right-angle side of each triangle is equal to half of the unit period; and the fourth layer and the fifth layer are completely the same as the second layer and the first layer. According to the invention, linear polarized waves can be effectively converted into circularly polarized waves in a microwave frequency band, high light transmittance can be maintained, and the device is suitable for being applied to intelligent windows, photovoltaic-microwave hybrid energy systems and other scenes.

The invention relates to a mobile device and measurement method developed to non-detructively measure the strength of concrete using electromagnetic (EM) waves in the microwave (MW) frequency band, which shows the resistance of the structure against earthquakes and external effects by measuring the strength of the concrete without damaging the reinforced concrete structure. The technical field of the invention is the non-destruuctive measurement of concrete strength using electromagnetic waves (EMW) in the microwave frequency band. This method is an alternative to destructive measurements by taking cores from structural elements such as columnsi beams, and slabs within the construction field, thus preventing damage to structures due to strength measurements and providing more rapid and non-destructive measurements from more regions. Results are evaluated using artificial intelligence techniques, providing a much more accurate strength measurement result instantly.

The invention provides a high-sensitivity magnetic field measurement method based on a quantum measurement principle and a related device, and belongs to the technical field of magnetic field measurement. The method comprises the following steps: correcting a zero field splitting parameter by using an initial magnetic field to enhance the stability of compression strength, and driving an NV cluster to generate a spinning compression state through microwaves to obtain a compression state probe; taking the compressed-state probe as an initial state of the quantum probe, and performing space-time polarization modulation decoupling on the target magnetic field and the environment magnetic field to obtain a decoupling signal; performing quantum phase-locked interference processing on the decoupling signal and a given reference microwave frequency to obtain a frequency shift signal; and performing magnetic field integral reconstruction and sensitivity calibration by using the frequency shift signal and combining the compression parameter of the compressed probe to obtain a final target magnetic field at the detection moment. Based on the quantum measurement principle, in combination with quantum coherent regulation, space-time modulation decoupling and the like, accurate extraction of the target magnetic field can be realized in a high electromagnetic interference environment, and the measurement sensitivity and accuracy are improved.

The invention relates to the technical field of hydrogen production, in particular to a catalytic integrated system for hydrogen production through ammonia cracking and a conversion method. Comprising a raw material pretreatment unit, a gradient catalytic reaction unit, a product separation unit and an intelligent regulation and control unit which are sequentially connected, the raw material pretreatment unit is used for purifying an ammonia gas raw material in a manner of combining multi-stage pressure swing adsorption with microwave dehydration, the operation pressure of the pressure swing adsorption stage is gradually increased along the airflow direction, and the particle size of an adsorbent filled in each stage of adsorption tower is gradually reduced along the airflow direction; microwave frequency in the microwave dehydration stage is dynamically adjusted along with water content of raw materials; the gradient catalytic reaction unit comprises at least three catalytic reaction cavities which are connected in series, and the catalyst active component loading capacity of each catalytic reaction cavity is distributed in a manner of increasing progressively along the airflow direction; according to the invention, deep synergy of each unit can be realized, and the ammonia cracking hydrogen production efficiency of the overall performance of the system is improved.

A current measurement method based on a quantum technology judges the range of formant appearance after current change of a measured wire through a frequency sweep result based on feature points, adaptively locks microwave frequency for frequency sweep, reduces the time cost of the frequency sweep process, greatly compresses the microwave frequency sweep time, and improves the measurement accuracy. The quantum state signal extraction speed can be remarkably improved while the relative high sensitivity is kept, non-contact real-time current measurement is achieved, and the method is characterized by comprising the steps that an atom source is close to a measured wire to couple a magnetic field signal generated by current in the measured wire; the atomic quantum state control system of the atomic source is connected with an upper computer through an electrical integration module, based on the optical detection magnetic resonance technology, in the measurement process, feature points are selected near formants of optical detection magnetic resonance for frequency sweeping, the positions of the feature points are updated in a self-adaptive mode based on the frequency sweeping result of the feature points, and the measurement accuracy is improved. A microwave signal frequency band is adaptively matched with a formant, a current measurement value is obtained, global frequency sweeping is replaced by feature point frequency sweeping, and the measurement speed is increased.

The present invention discloses an intelligent skin integrating microwave sensing, radiation and scattering, which relates to the field of electromagnetic scattering control and antenna technology. An antenna array detects incident electromagnetic wave signals in real time and transmits them to an intelligent control system via a signal transmission line. After processing the received signals, the intelligent control system generates a control signal based on the information of the incident electromagnetic wave and a preset electromagnetic control target, and transmits the control signal via the signal transmission line to an active metasurface and an antenna array respectively, so as to dynamically control the electromagnetic waves scattered by the active metasurface and the electromagnetic waves radiated by the antenna array. The present invention can detect incident electromagnetic waves in the microwave frequency band, and can dynamically and actively control the scattering and radiation of electromagnetic waves in real time.

The application provides a modified fluorogypsum-based steel structure fireproof coating and a preparation method thereof, and comprises the following steps: 1) mixing and treating carbide slag and fluorogypsum raw materials to obtain a first intermediate; 2) microwave heating treatment of the first intermediate, wherein the microwave heating treatment process comprises primary heating treatment and secondary heating treatment, and a second intermediate is obtained; 3) secondary mixing treatment of the second intermediate and an excitation agent to obtain modified fluorogypsum; wherein the microwave power of the microwave heating treatment is 300W-500W, and the microwave frequency is 2450MHz-2500MHz; the excitation agent comprises at least two of a sulfate, a silicate and a water-soluble aluminum salt. The method eliminates fluorine ions and acidic impurities in fluorogypsum waste residues which are harmful to the human body and the environment, excites the hydration activity of the fluorine ions and the acidic impurities, improves the high-temperature resistance of the fluorine ions and the acidic impurities, and further makes the fluorine ions and the acidic impurities meet the performance requirements of the modified fluorogypsum-based steel structure fireproof coating, and increases the fluorogypsum waste residue consumption path.

This disclosure provides an electronic control readout system and method for quantum diamond atomic force microscopy. The system includes: a system control readout module, a magnetic measurement algorithm module, and a magnetic measurement control and readout module. The magnetic measurement control and readout module is used to respond to the control signal of the system control readout module by emitting a laser pulse sequence and a microwave pulse sequence of a preset frequency to the quantum diamond probe located at the i-th pixel position of the sample to be tested, and then acquiring the analog fluorescence signal of the quantum diamond probe at the i-th pixel position and outputting the digital fluorescence signal of the i-th pixel. The magnetic measurement algorithm module is used to respond to the control signal of the system control readout module by obtaining the resonance frequency at the i-th pixel position and the preset frequency at the i+1-th pixel position according to the fluorescence photon number of the i-th pixel corresponding to the digital fluorescence signal of the i-th pixel, the resonance frequency at the (i-1)-th pixel position, and a microwave frequency lookup table.

The present invention discloses a digital channelized radio frequency storage system. The digital channelized frequency storage module of the radio frequency storage system can perform frequency domain separation on the input signal before storing it, which not only avoids the problem of traditional methods storing superimposed signals and interfering with the output signal, but also effectively avoids the problem of traditional frequency guidance methods that frequency measurement is easily interfered with when multiple signals arrive at the same time. The introduction of the digital channelized frequency storage module can support the acquisition and storage of multiple simultaneously arriving signals, thereby improving the frequency measurement accuracy, achieving the technical effect of precise frequency guidance, and can be used to counter coherent radar. At the same time, the high-speed, multi-bit A / D converter provided by the present invention, after the operating frequency enters the microwave frequency band, can directly acquire and reconstruct the signal in the intermediate frequency or radio frequency band, and maintain the subtle information characteristics such as the phase of the original signal, thereby ensuring that the output signal has good coherence, and can achieve high radio frequency storage accuracy and long signal storage time.

The application provides a microwave millimeter wave three-frequency co-aperture antenna combining a monopole array and a transmission array, comprising a plurality of layers of PCB boards, the plurality of layers of PCB boards comprising a first dielectric plate, a second dielectric plate, a third dielectric plate, a fourth dielectric plate, a fifth dielectric plate and a sixth dielectric plate, the surfaces of the first dielectric plate, the second dielectric plate, the third dielectric plate, the fourth dielectric plate, the fifth dielectric plate and the sixth dielectric plate are provided with metal layers, the metal layers on the first dielectric plate, the second dielectric plate, the third dielectric plate and the fourth dielectric plate are provided with rectangular patches, the peripheries of the rectangular patches are provided with annular slots, the annular slots are connected with the rectangular slots, the metal layers are further provided with a first slot and a second slot, and the metal layer of the fourth dielectric plate is further provided with a microwave frequency band feed network; the metal layer of the fifth dielectric plate is provided with an I-shaped slot; and the metal layer of the sixth dielectric plate is provided with a microstrip antenna. The application can effectively realize high aperture utilization, high structural multiplexing rate and miniaturization of the overall antenna.

The invention relates to a core temperature sensor (CTS) for use with a microwave cooking appliance that generates microwaves within a specific microwave frequency band for cooking food, wherein the core temperature sensor (CTS) comprises: at least one temperature sensor (TS), an antenna (ANT), a high-frequency oscillator (1) whose output signal can be fed into the antenna (ANT) and whose signal frequency lies outside the microwave frequency of the microwave cooking appliance, a modulation device (OOK) configured to generate a pulse train from the output signal of the high-frequency oscillator (1) by means of amplitude modulation, which corresponds to digital temperature data generated by means of the at least one temperature sensor (TS), and an electrical energy storage device (BAT) for supplying electrically operated components (MCU, TS, OSZ-AMP) of the core temperature sensor (CTS).The invention also relates to a system comprising a core temperature sensor and a cooking device, comprising a receiver for receiving electromagnetic waves emitted by the core temperature sensor and a control device configured to operate the cooking device based on information contained in the received electromagnetic waves.

The invention provides a metal patch loaded miniaturized dielectric resonator antenna for a base station, and relates to the technical field of wireless communication, a specific parasitic metal patch is introduced at the bottom of a dielectric resonator, the limitation that the traditional design only depends on geometric dimension to adjust the frequency is broken through, the TM12 high-order mode frequency is obviously pulled down to be close to a fundamental mode TM10 and fusion is realized, and the antenna has the advantages of being simple in structure and convenient to use. On the premise that the size of the antenna is not increased, the working bandwidth is expanded to 3.4-4.0 GHz. Through the structural design, a cross-shaped groove structure is loaded in the central area of the dielectric resonator, a current path of a TM20 parasitic mode is cut off accurately, directional diagram distortion and cross polarization interference caused by the mode are effectively suppressed, and it is ensured that the antenna has stable radiation performance. Therefore, the antenna has excellent broadband and radiation characteristics, can still keep compact physical size, low profile structure and simple processing technology, and meets the urgent demand of a microwave frequency band wireless communication terminal on high performance and miniaturization antennas.

The invention relates to an online detection device and method for the moisture content of an aromatic line of a cigarette filter stick. The device comprises a guide assembly, one end of which is used for guiding an incense line impregnated with perfume from a perfume barrel, and the other end of which is used for guiding the incense line out to a filter stick forming cigarette gun; the guide assembly is used for folding the incense lines into a plurality of strands of non-intersecting incense lines and conducting the incense lines; the microwave resonant cavity is used for transmitting a microwave detection signal with a preset microwave frequency to an incense line area in the cavity; the radio frequency detection module is used for detecting a microwave response signal of the incense line area aiming at the microwave detection signal and acquiring a water content map of the incense line according to the microwave response signal; the data processing module is used for comparing the water content map of the incense line with a standard water content map corresponding to a preset microwave frequency to obtain the water content of the incense line in the incense line area; according to the water content of the incense lines in the incense line area and the length of the incense lines in the incense line area, the water content of the incense lines in the incense line area is obtained. The device can improve the detection accuracy of the water content.

This invention discloses a method and system for drying and curing non-metallic materials based on frequency-conversion microwaves. The method includes: placing the non-metallic material to be treated in a microwave resonant cavity, with a microwave-sensitive agent coated on the surface of the non-metallic material; setting the microwave frequency modulation range, power gradient, and processing time according to the type, thickness, and target drying / curing degree of the non-metallic material; starting a microwave generator and using frequency-conversion microwaves to dry and cure the non-metallic material through a stepped heating strategy and intermittent microwave radiation mode; and turning off the microwave generator and using natural cooling or forced air cooling to lower the temperature of the non-metallic material to room temperature. Using this invention, heating efficiency can be improved, and the uniformity and stability of the material drying and curing process can be ensured.

The invention discloses a radio frequency microwave frequency multiplier which comprises an input resonance filter network, an oscillation amplification network and an output resonance filter network, the oscillation amplification network is adopted as a core architecture, and high power and high gain in a microwave frequency band can be achieved. And meanwhile, the self-adaptive linearization feedback network is used for adjusting the linearity component of the stacked field effect transistors at the bottom layer of the self-bias negative feedback amplification network, so that the whole radio frequency microwave frequency multiplier obtains good high gain, high linearity and high power output capability.

The application discloses a preparation method of high-purity silicon carbide powder, which comprises the following steps: mixing carbon source raw materials and silicon source raw materials, then directly synthesizing the silicon carbide powder by microwave heating solid-phase reaction, cooling the silicon carbide powder, crushing the powder, purifying the powder, and then treating the high-purity silicon carbide powder; a step of continuously rotating the mixed raw materials is arranged in the microwave heating process; the molar ratio of the carbon source raw materials to the silicon source raw materials is 0.8:1-1.1:1; the microwave heating process is that a 300kW tunnel microwave oven is used to microwave heat the mixed carbon source raw materials and silicon source raw materials; the microwave frequency is 915MHz, and an argon protective atmosphere is used during the microwave heating. The application dynamically changes the field distribution, ensures uniform microwave field distribution, ensures that the reaction materials are uniformly heated, and provides a good balanced thermal field for the sample.

The application provides an electromagnetic transmittance enhancer, and belongs to the technical field of microwave frequency electromagnetic wave regulation and control, comprising a plurality of super units arranged in a rectangular shape. Each super unit comprises a dielectric base, a dielectric substrate and a metal patch, the dielectric substrate is vertically arranged at the middle position on the top of the dielectric base; the metal patch is in an inverted L shape and is arranged on one side of the dielectric substrate; when the electromagnetic wave in the air is incident on the upper surface of the electromagnetic transmittance enhancer, the plurality of super units will simultaneously resonate, the electric field component of the transmitted electromagnetic wave will excite electric dipoles of different lengths in the horizontal and vertical directions of the metal patch, and the electric dipoles will interfere with the incident electromagnetic wave to cancel each other out, so that the resonance zero point of the synthesized dipoles points to the direction of the reflected wave, and the electromagnetic wave is transmitted forward from the gap channel between adjacent units. The electromagnetic transmittance enhancer provided by the application can improve the transmittance of electromagnetic wave transmission to the medium under a large incident angle.