30 results about "Radiation power density" patented technology

A method for measuring electromagnetic radiation pattern and gain of radiator using TEM waveguide is disclosed. The method includes the steps of: a) measuring powers of output port of a transverse electric and magnetic (TEM) waveguide by changing arrangements of the radiator located within the TEM waveguide; and b) estimating a radiation power density of the radiator in free space, wherein the radiator is modeled as a dipole moment based on the powers of the output port of the TEM waveguide.

The invention discloses a multi-frequency terahertz radiation source based on a Dirac semi-metal transmission grating. The multi-frequency terahertz radiation source comprises a transmission grating made of a Dirac semi-metal material, moving electrons sweep past the surface of the grating to excite two types of surface plasma wave modes in the grating, the dispersion characteristics and excitation conditions of the two modes are different, but the two modes can be converted into enhanced multi-frequency coherent terahertz radiation by grating diffraction, and the radiation power density is enhanced by surface plasma waves by two to three orders of magnitude. The multi-frequency terahertz radiation source can be used for development of the coherent terahertz radiation source with room temperature working, multiple frequencies and high power capable of covering the whole terahertz wave band.

The invention discloses a dual-frequency terahertz radiation source based on a Dirac semi-metal surface plasmon wave. The dual-frequency terahertz radiation source comprises a dielectric substrate which is covered with a Dirac semi-metal film and has a buffer layer, and moving electrons sweep the surface of a film to excite surface plasmon waves of two modes. When the dielectric constant of the buffer layer is lower than the dielectric constant of the substrate, the two modes can be directly converted into coherent Cherenkov terahertz radiation in the substrate, the power density of the radiation is enhanced to two to three orders of magnitude by the surface plasmon waves, and the dual-frequency terahertz radiation source can be used to develop a dual-frequency coherent terahertz radiationsource with room temperature operation, high power and the coverage of an entire terahertz frequency band.

The invention belongs to the field of laser initiating explosive devices, and particularly relates to an optical window based on a double-self-focusing lens structure. The optical window comprises anignition laser, a detection laser, an optical switch, a photoelectric detector, a first self-focusing lens, a second self-focusing lens and a sapphire transparent window, wherein the ignition laser isconnected to the optical switch through an ignition input fiber and a detection input fiber correspondingly, the optical switch is connected with the first self-focusing lens through the ignition optical fiber, the photoelectric detector is connected with the first self-focusing lens through the detection optical fiber, the second self-focusing lens and the sapphire transparent window are sequentially placed behind the first self-focusing lens, and optical axes of the first self-focusing lens, the second self-focusing lens and the sapphire transparent window are coaxial. According to the optical window, the technical defects of an existing laser initiating explosive device optical window are overcome, the laser radiation power density is avoided, a certain proportion of detection light isguaranteed to enter the detection optical fiber, the consistency of the reflectivity of the initiating explosive devices is improved, and the capability of the chamber pressure resistance of the optical window is improved.

The invention discloses a visual simulation prediction method for electromagnetic radiation of a base station based on a simplified directivity function. Through mathematically simplifying an antennadirectivity attenuation function, practical simplified calculation of any spatial point is realized; each equivalent position curve of the antenna space limit value is predicted to realize predictionof a single-antenna three-dimensional visual contour surface; meanwhile, prediction of a space electromagnetic radiation power density visualization curve in the vertical direction and prediction of aground 1.7 m high electromagnetic radiation power density visualization curve are achieved. Through open design and conventional multi-parameter adjustment, the established prediction model can accurately calculate and visualize the maximum electromagnetic radiation intensity of a certain position of a single base station, has great reference value for rapid site selection of the base station, electromagnetic radiation environment influence visualization evaluation and environment protection visualization, and has certain social benefits.

The invention discloses a radiation source capable of dynamically tuning radiation parameters and a radiation parameter tuning method. The radiation source comprises a dielectric substrate, a waveguide and an electrode array are arranged on the dielectric substrate, a plurality of graphene strips are arranged on the waveguide, a gap is formed between every two adjacent graphene strips, and the electrode array is used for adjusting the bias voltage of each graphene strip so as to dynamically tune the radiation parameter of the radiation source under the condition that the radiation frequency is not changed. The metasurface structure formed by the graphene strip is adopted, a waveguide mode is radiated into the space, and on the basis that the grating structure is formed, under the condition that the radiation frequency is not changed, radiation parameters such as the line width and the grating period are actively and dynamically tuned by changing the bias voltage on the graphene strip; in addition, the line width can be tuned in a wider range and can be narrowed to 1 * 10 <-8 > times of the radiation frequency to the minimum, and the radiation power density is remarkably enhanced.

An embodiment of the present invention provides a TOF ranging system and a movable platform. The TOF ranging system includes: a light emitter, a receiver, a controller, and an optical system. The optical system includes a first optical signal processing device and a second optical signal processing device. At least one of the devices; the optical signal emitted by the light emitter passes through the first optical signal processing device to improve the radiation power density of the optical signal emitted by the light emitter; the optical signal reflected by the target object passes through the second optical signal processing device to improve the receiving The intensity of the light signal reflected by the target object received by the detector. The embodiments of the present invention can improve the signal-to-noise ratio of the TOF ranging system by increasing the radiation power density of the optical signal emitted by the light emitter, and / or increasing the intensity of the optical signal reflected by the target object received by the receiver, so that the TOF ranging system Target objects that are far away from the TOF ranging system can be detected, thereby improving the ranging range of the TOF ranging system.

The invention discloses a sub-array dividing method of a rectification antenna array. The method comprises steps of inputting rectification antenna array feature parameters, rectification channel efficiency parameters, radiation power parameters and sub-array dividing type parameters, acquiring a radiation power density curve, acquiring a rectification channel efficiency curve, acquiring a sub-array rectification efficiency expression formula, building a target function according to the sub-array rectification efficiency, conducting even sub-array division to the rectification antenna array, selecting an optimized design variable according to the sub-array dividing type, acquiring a constraint function according to the sub-array dividing type, building a rectification antenna array sub-array dividing optimization module, solving a rectification antenna array sub-array dividing optimization module, outputting a sub-array dividing scheme, and acquiring each sub-array module unit number of the sub-array dividing scheme. With rectification efficiency as the target, sub-arrays of the rectification antenna array is divided; and maximum of the whole rectification efficiency of the rectification antenna array can be achieved.

The invention discloses a method for calculating the radiation power density of an antenna of a mobile communication base station. The method comprises the steps that a horizontal plane normalization directivity function and a vertical plane normalization directivity function are established, a measuring point away from a vertical plane by the assigned distance is selected for the antenna, the fitting coefficient of the horizontal plane normalization directivity function of the antenna is obtained by obtaining the antenna radiation power data at the measuring point and performing fitting, the final gain value from the antenna of the mobile communication base station to an antenna panel is determined based on the antenna theoretical gain value of the mobile communication base station, a computing model for the radiation power density of the antenna of the base station is established according to the fitting coefficient of the horizontal plane normalization directivity function of the antenna and the finial gain value from the antenna to the antenna panel, and the antenna radiation power density suitable for any azimuth angle can be worked out. The method has the advantages of being high in accuracy and suitable for any azimuth angle.

The invention relates to an online monitoring instrument, which is used for the online monitoring of air quality, and comprises an infrared light source. The infrared light source comprises a silicon-carbon rod, wherein the silicon-carbon rod comprises two electrodes, and the two electrodes are used for the silicon-carbon rod to access a closed loop of a power supply. The silicon-carbon rod is used as a radiation light source, the silicon-carbon rod has a small resistance value; and the silicon-carbon rod has a function similar to the blackbody radiation under the electrified normal working situation, and the radiation power density is large, so the monitoring precision of the online monitoring instrument can be improved. At the same time, raw materials for producing the online monitoring instrument are inexpensive and are simple to process and mold, so the cost is low, and the online monitoring instrument is easy to popularize.

A method of using linear array CCD to measure central position of light beam includes presenting radiation power density of CCD surface light spot in Gaussian or quasi-Gaussian distribution , setting error limit and selecting end-off threshold of digital signal output by CCD and relative circuits , applying weighted- regression method to calculate out estimation value of central position for effective digital signal of end-off quasi-Gaussian distribution and using Monte Carlo figure to simulate error distribution for setting out width range of light beam .

The invention relates to the field of traditional Chinese medicine pharmacy, in particular to a method for extracting total flavonoids of callicarpa nudiflora. The method comprises steps as follows: crushing a medicinal material, namely, the callicarpa nudiflora, adding an ethanol aqueous solution with the additive amount being 12-24 times the weight of the callicarpa nudiflora, soaking for 20-40 min, performing extraction with microwaves, controlling the radiation power density of the microwaves to be in a range of 15-30 W / g and the irradiation time in a range of 150-180 s, controlling the temperature of the ethanol aqueous solution under the boiling point, then performing sealing and cooling at the room temperature, repeating the microwave extraction and cooling steps for 4-6 times, performing ultrafiltration on an extract by a hollow cellulose membrane with the molecular weight cutoff of 2000, filtering a filtrate with a ceramic membrane, and concentrating and then heating the filtrate until the filtrate is dry to obtain a total flavonoid product.

The invention discloses a base station electromagnetic radiation visualization simulation prediction method based on a simplified directional function, the steps of which are as follows: through mathematical simplification of the antenna directional attenuation function, the practical simplified calculation of any point in space is realized; each equivalent position curve of the antenna space limit is predicted, Realize the prediction of the three-dimensional visualization isosurface of a single antenna; at the same time, realize the prediction of the visualization curve of the space electromagnetic radiation power density in the vertical direction, and the prediction of the visualization curve of the 1.7m high electromagnetic radiation power density on the ground. Through the open design and conventional multi-parameter adjustment, the prediction model established by the present invention can accurately calculate and visualize the maximum electromagnetic radiation intensity at a certain position of a single base station, which is useful for rapid site selection of base stations, visual evaluation of electromagnetic radiation environmental impact, and visualization of environmental protection. Great reference value, with certain social benefits.

The present invention provides a residual passive intermodulation test method. The residual passive intermodulation test method comprises: performing self calibration of the system for testing so as to satisfy a presetting test requirement; scanning the background in a testing place so as to check and remove other interferences; performing calibration of the radiation power density of the system for testing according to the max radiation power density of the position where a satellite to be measured is located so as to allow the radiation power density of the system for testing to reach the level of the max radiation power density; and sampling and obtaining the max radiation power density of the satellite to be measured at different positions relative to the different positions in the testing field, and correspondingly obtaining different radiation power densities of the system for testing so as to obtain relatively stable radiation power density reading. According to the invention, an appropriate wireless test system is built and is calibrated so as to ensure that the passive intermodulation index of the satellite test environment reaches the requirement of the satellite passive intermodulation test, and therefore, the test result authenticity is ensured and the test error influence is decreased.