346 results about "Characteristic impedance" patented technology

The invention relates to the technical field of vehicle charging station operation and maintenance management, and particularly discloses a new energy vehicle charging station operation and maintenance management system and method based on the Internet of Things, and the method comprises the steps: collecting high-frequency harmonic characteristic data in a charging process in real time, and generating harmonic-impedance spectrum combined monitoring data; extracting dynamic attenuation gradient data of the line characteristic impedance; when the dynamic attenuation gradient data is lower than a preset critical safety threshold value, triggering a charging mode switching instruction; the charging piles are controlled to be switched into a charging mode, the phase difference parameters of the multiple charging piles are dynamically optimized, and a phase difference dynamic adjustment instruction set is generated; and finally, self-adaptive correction of the impedance compensation amount is carried out through the MEC equipment, and by self-adaptive correction of the impedance compensation amount, the system can maintain that the overall impedance is constantly greater than a critical safety threshold value, and power loss and equipment damage caused by impedance mismatch are avoided. The real-time feedback mechanism is helpful for improving the energy efficiency of the system, reducing the operation cost and ensuring the long-term reliability of the charging infrastructure.

The invention relates to the technical field of integrated circuit testing, in particular to a distance-adjustable probe connector device which comprises an impedance detection unit which comprises a connector fixing part, a connector rotating part, a single connection port, a signal probe and a grounding probe. The impedance data unit is used for determining a characteristic impedance value of the tested microstrip line based on data acquired by the signal probe and the grounding probe; the pressure detection unit is used for determining the contact pressure according to the telescopic displacement of the signal probe and the grounding probe; the control unit determines the allowable range of the contact pressure of the probes based on the line width of the microstrip line to be tested and the distance between the probes, and adjusts the angle between the grounding probe and the surface of the PCB based on the contact pressure difference between the signal probe and the grounding probe and the line width of the microstrip line. And adjusting the contact pressure of the signal probe to obtain the effective characteristic impedance value of the tested microstrip line. According to the invention, the angle and pressure of the grounding probe are intelligently adjusted, and the problem of impedance measurement drift caused by pressure imbalance of double probes is eliminated.

The invention discloses an image analysis method and system for quality control traceability of a satellite navigation board, and relates to the technical field of image processing. The method comprises the following steps: synchronously acquiring an image and three-dimensional point cloud data of a radio frequency transmission line area through a high-resolution area array CCD camera and a laser contourgraph; acquiring a transmission line contour based on image identification, and constructing a three-dimensional radio frequency line model through point cloud fitting; detecting the line width and the distance to the ground plane by using the model, and calculating the impedance prediction complexity in combination with a data acquisition error; dynamically calling a characteristic impedance prediction engine based on the complexity to obtain a predicted characteristic impedance sequence; and quality defect judgment is carried out, and traceability control is carried out on defective products. According to the method, a complete technical chain from geometric dimension detection to electrical performance evaluation is established, hidden defects which are difficult to find by a traditional method can be effectively identified, and the quality control precision and the product yield of the satellite navigation board are improved.

The invention discloses an impedance self-adaptive high-frequency probe, a probe card and a testing method, and belongs to the technical field of semiconductor high-frequency testing. When an existing high-frequency probe is used for a crimping test, a conductive probe body of the existing high-frequency probe generates mechanical deformation due to contact pressure, so that characteristic impedance is deviated, and uneven pressure in an array causes impedance dispersion. The problem is solved by coating the outer side of the conductive needle body with a composite material layer, the composite material layer is composed of an elastic insulating matrix and metal particles dispersed in the elastic insulating matrix, the metal particles have bimodal particle size distribution, and the total integral number is 30%-40%. When the probe is pressed, the composite material layer is subjected to reversible microscopic reconstruction, the effective dielectric constant of the composite material layer is increased along with the increase of the pressure, and the generated impedance change can counteract the impedance drop caused by the deformation of the conductive probe body, so that the self-adaptive stability of the characteristic impedance of the probe under the change of the pressure is realized. The impedance dispersion of the probe array can be remarkably reduced, the consistency and precision of high-frequency testing are improved, and the process compatibility is good.

The invention provides a liquid crystal phase shifter, an antenna device and an antenna system, and relates to the technical field of communication. The liquid crystal phase shifter comprises a first dielectric substrate, a grounding metal layer, a dielectric functional layer, a micro-strip signal line and a second dielectric substrate which are stacked in sequence, the grounding metal layer is provided with a plurality of groups of grid structures which are arranged at intervals, and each group of grid structure comprises a plurality of grids which are distributed at intervals; and the length direction of the micro-strip signal line is parallel to the arrangement direction of the plurality of groups of grid structures. In the embodiment of the invention, the defected ground structure is formed by the plurality of groups of grid structures on the grounding metal layer, so that a relatively wide microstrip signal line can be conveniently arranged, and a relatively thin dielectric functional layer can be arranged under the condition that the characteristic impedance of the liquid crystal phase shifter is ensured, so that the miniaturized liquid crystal phase shifter is realized; in addition, when phase shifting is carried out based on the liquid crystal phase shifter, the thinner dielectric functional layer is convenient for reducing loss and improving response speed, so that the phase shifting performance of the liquid crystal phase shifter is improved.

The invention relates to the field of electrical variable measurement, in particular to an insulating layer compactness detection method for a mineral cable, which comprises the following steps: firstly, acquiring a time domain reflection signal of the cable, and carrying out denoising pretreatment by utilizing synchronous average and wavelet transform; and then, carrying out spectrum analysis on the discrete signal segments, calculating a spectrum centroid offset rate to determine high-frequency energy attenuation, and constructing a dynamic compensation gain coefficient according to the high-frequency energy attenuation. And then, improving a traditional layer stripping algorithm by using the gain coefficient, eliminating calculation deviation caused by transmission loss, and accurately reconstructing characteristic impedance distribution along the cable. And finally, by comparing the deviation between the reconstructed impedance and the nominal impedance, positioning and judging the abnormities of the compactness of the insulating layer of the cable and the eccentricity defect of the cable core are realized.

The invention discloses a 16-in-one high-power combiner working in a radio frequency band, and belongs to the technical field of fusion radio frequency heating. The invention comprises a coaxial input hard feeder line, a radial transmission line (RTL), a gradient impedance matching coaxial line and a coaxial output hard feeder line. The physical size is designed through theoretical calculation, electromagnetic field distribution is optimized through simulation, 16 radio-frequency signal input ports are designed through radial symmetric topology, a radial transmission line serves as a main synthesis path of radio-frequency signal source power, the power input by the 16 radio-frequency signal source ports is subjected to one-step efficient synthesis in the center of the radial transmission line, and the radio-frequency signal source power is obtained. And the 50-ohm characteristic impedance standard output of the synthesized radio frequency signal power is realized through an impedance matching technology. The sixteen-in-one power combiner designed by the invention has the characteristics of high synthesis efficiency, symmetrical structure, good amplitude and phase consistency, high isolation, low return loss, low reflection loss, simple design structure, easiness in manufacturing and the like.

The utility model belongs to the technical field of vibration and noise reduction, and relates to an external interference noise suppression module integrated in a hydrophone. The module comprises a high-characteristic-impedance metal round rod and two low-characteristic-impedance rubber round rods, the rubber round rods are connected to the two ends of the metal round rod, the cross sectional areas of the metal round rod and the rubber round rods for transmitting interference elastic waves are the same, and the lengths of the two rubber round rods are different, so that half-wavelength total transmission is restrained. The interference longitudinal wave passes through the noise suppression module, most energy is lost, and the interference noise is effectively suppressed. The utility model has the effects and benefits that the external interference noise is reduced, and the anti-interference level of the hydrophone is improved. The device is widely applied to noise suppression design of the hydrophone, is simple in structure, is convenient to integrate in the hydrophone, and can stably work in seawater for a long time.

The invention belongs to the technical field of superconducting coaxial cable processing, and particularly relates to a superconducting coaxial cable and a preparation method and application thereof. The superconducting coaxial cable is composed of an outer conductor, a PTFE insulation module and an inner conductor arranged in the PTFE insulation module, the PTFE insulation module is a cylinder with a through hole in the center, supporting structures are symmetrically arranged at the two axial ends of the cylinder, a non-supporting structure is arranged in the middle of the cylinder, and the specific structure of the PTFE insulation module effectively regulates and controls the effective dielectric constant of an insulator. Therefore, the characteristic impedance of the superconducting coaxial cable is flexibly and finely adjusted, and the application requirement of a quantum computer signal transmission device on the characteristic impedance is met. The PTFE insulating module is prepared by pressing and sintering, and NbTi filaments are embedded into the prepared PTFE module by a heating method and are assembled with an outer conductor to form the superconductive coaxial cable. The method is simple in process, convenient to assemble and suitable for large-scale production.

Circuitry and method are described for enabling multiple loads on a differential low voltage differential signaling pair (M-LVDS). A printed circuit board (PCB) contains a M-LVDS driver and leads that route a main channel that carries a differential signal from the driver to an area in which loads are populated. The main channel is split into branches that contain application-specific integrated circuits (ASICs) as the loads. The branches have the same characteristic impedance as the main channel. Filters are disposed in each branch and are coupled between the driver and the ASICs. Each filter is a first order or higher filter. Fewer filters than ASICs are on each branch, with the filters being disposed between the driver and ASICs closest to the driver (with smaller propagation delay). The filters are configured differently at each ASIC input to compensate for the delay.

The invention discloses a phased-array antenna control method and system based on impedance matching, a medium and a product, and relates to the technical field of antennas. In the method, before the phased-array antenna works, a target impedance matching parameter is calculated for active input impedance under each preset scanning angle point; establishing a target mapping relation table based on the plurality of preset scanning angle points and the corresponding target impedance matching parameters; during the working period of the phased-array antenna, receiving a target scanning angle, and calculating to obtain a corresponding beam pointing phase value for each antenna unit in the antenna array according to the target scanning angle; determining a real-time impedance matching parameter based on the target scanning angle and the target mapping relation table; and loading the beam pointing phase value to a phase shifter in the feed network, and applying a real-time impedance matching parameter to the dynamic impedance matching network, so that the input impedance of the antenna array is matched with the characteristic impedance of the feed network. By implementing the technical scheme provided by the invention, the radio frequency performance of the phased-array antenna is improved.

The invention provides a double-layer thin-plate underwater sound reflection structure supported by hollow balls, which belongs to the technical field of underwater sound reflection materials and comprises upper and lower rigid plates, a middle hollow ball group arranged in a certain manner and peripheral support beams. The rigid hollow sphere is adopted as a pressure-bearing component of the underwater anti-sound sandwich structure, and the advantage that the spherical structure is not prone to deformation is utilized, so that the whole structure only generates low deformation quantity under high hydrostatic pressure; by means of the characteristic that the contact area between the spherical structure and the sound transmission layer (thin plate) is small, sound energy leakage to the interior is reduced; by means of the characteristic that a large amount of air exists in the spherical shell, the equivalent characteristic impedance of the sound reflecting layer is further reduced, and the sound reflecting capacity is enhanced; in addition, the method has the characteristics of flexibility and universality, can integrate the requirements of working depth, anti-sound performance indexes and the like, and can change the parameters of arrangement density, diameter, shell thickness and the like of the hollow sphere; the invention also has the characteristics of light weight, easiness in transportation and convenience in use.

The utility model relates to an antenna and electronic equipment, and the antenna comprises a substrate, and a first radiator and a second radiator which are the same in shape. Each of the first radiator and the second radiator comprises a first part and a second part; wherein the first part is semicircular, and the first straight edge of the second part is in butt joint with the diameter edge of the first part; the first radiator and the second radiator are in mirror symmetry, and the opening directions of the first part of the first radiator and the first part of the second radiator are opposite; the first radiator is arranged in the upper half area of the front face of the substrate, and the second radiator is arranged in the lower half area of the back face of the substrate. Therefore, the two radiators distributed in the upper area and the lower area of the substrate are in mirror symmetry, and each radiator is provided with a semicircular first part and a semicircular second part, so that the current of the upper radiator and the current of the lower radiator can be kept in the same direction in an ultra-wideband range, the omnidirectional radiation characteristic of the antenna is realized, and the characteristic impedance is gentle along with frequency conversion.

This application relates to the field of radio frequency (RF) power supply technology, and discloses a gain calibration method, a dynamic impedance testing method, equipment, and dielectric. The gain calibration method includes: acquiring multiple RF power measurements, where the RF power measurements are the output power measurements of an RF power supply in an open-loop state under multiple load impedance values; performing two-dimensional interpolation fitting in the complex plane of reflection coefficient based on the load impedance values ​​and the RF power measurements to obtain a continuous power distribution; selecting a minimum RF power value in the complex plane of reflection coefficient based on the continuous power distribution to obtain a target minimum RF power value; and calculating the gain of the RF power supply based on the target minimum RF power value, the load impedance value corresponding to the target minimum RF power value, and a preset characteristic impedance value. The embodiments of this application can improve the accuracy of RF power supply gain calibration and reduce the impact of environmental noise and small impedance fluctuations.

The invention relates to the technical field of radio frequency processing, discloses a radio frequency chip fan-out packaging design method based on machine learning optimization, and aims at the design of high-speed packaged high-frequency pins. A high-frequency pin GSG structure design process is decoupled into a mapping problem of an RDL signal line length L, a signal line and ground line spacing S, a signal involute angle alpha and pin characteristic impedance, loss and return loss electrical performance. And by taking the solving process of the positive problem as a training environment, reversely solving a specific combination of GSG structure design size parameters meeting different design demand responses. Meanwhile, in the face of small-batch radio frequency chip product design of customized, small-crowd or technical exploration stage scenes with few products and various forms, a non-ergodic sample collection and later-stage small-amount adjustment mode is adopted, and the situation that ergodic simulation covers all parameter ranges to generate models and simulations in batches is avoided; and the earlier-stage investment time and computing power cost are higher than the small-batch production income.

The application discloses a kind of armored double-layer shielded dry reed relay and its manufacturing method.The dry reed relay includes dry reed tube, inner shield tube, coil framework, coil, outer shield shell, coil lead, shield lead, side plate, sealing assembly and switch lead.The armored double-layer shielded structure of the above-mentioned dry reed relay can solve the problem of dry reed tube contact characteristic impedance matching uniformity by means of inner layer shielding, solve the problem of relay coil magnetic field leakage and low-frequency electromagnetic field shielding by means of outer layer shielding, and realize the problem of relay structure complete shielding and distributed parameter uniformity by means of coaxial structure.

The application discloses a broadband multi-stage Gysel power divider based on an IPD process, comprising a microstrip structure layer, and first and second dielectric substrates and a ground metal layer; the microstrip structure layer adopts a multi-layer nested structure, each layer of the nested structure is formed by cascading multi-stage Gysel power division units, and is arranged on the upper surface and the interior of the first dielectric substrate, so that an integrated layout based on the IPD process is formed, and a planar spiral structure, an air bridge, a parallel plate capacitor, a thin film resistor and a layered ground unit structure are integrated; the planar spiral structure is equivalent to a specific characteristic impedance transmission line, the air bridge structure solves cross interference and suppresses a parasitic capacitor, the parallel plate capacitor structure calibrates equivalent reactance parameters, the thin film resistor effectively improves port isolation and heat dissipation, and the layered ground unit structure strengthens heat dissipation and ground reliability. The application can realize stable power distribution in a wide frequency band, and is suitable for the integration requirements of high-frequency, high-power and small-sized radio frequency front ends.

A Doherty amplifier according to the present disclosure comprises a main amplifier, an auxiliary amplifier, a distribution circuit that distributes signals to the main amplifier and the auxiliary amplifier, and a phase compensation circuit. The main amplifier has a first input matching circuit and a plurality of main amplification stages. The auxiliary amplifier has a second input matching circuit and a plurality of auxiliary amplification stages. The distribution circuit has a first line connected to the first input matching circuit and a second line connected to the second input matching circuit. The electrical length of the first line is such that the input impedance of the first line is higher than the characteristic impedance of the first line and the imaginary component is less than 10% of the real component when a small signal is input. The electrical length of the second line is such that the input impedance of the second line is higher than the characteristic impedance of the second line and the imaginary component is less than 10% of the real component when a small signal is input. The phase compensation circuit is provided in an inter-stage matching circuit of the plurality of main amplification stages or the plurality of auxiliary amplification stages.

The invention relates to the field of power line channel modeling, in particular to a power line channel modeling method, system, equipment and medium, power line channel data is actually measured and collected and preprocessed, channel characteristics are extracted, parameters such as characteristic impedance and propagation constant of a power line are calculated by using a transmission line theory, and the power line channel is modeled. Constructing an enhanced conditional generative adversarial network comprising a generator and a discriminator, inputting parameters obtained by theoretical calculation of a transmission line as conditional information in a training process, optimizing structures and loss functions of the generator and the discriminator, enabling the generator to generate a high-quality analog channel sample, fusing a deep learning model with a transmission line theoretical model, and obtaining a high-quality analog channel sample; according to the method, a mixed channel model is formed, model parameters are alternately trained and optimized, accurate prediction of transmission characteristics of the power line channel is realized, complex characteristics of the power line channel can be effectively modeled, and a reliable basis is provided for design optimization of a power line communication system.

The invention relates to the technical field of aviation electric connectors, and discloses an isolation coupler, which adopts tin soldering to fix a shell and a shell cover so as to ensure the sealing performance and the stability of the shell and prevent the influence of external interference on signal transmission. And meanwhile, the shielding layers of the signal input lead and the signal output lead are welded with the shell, so that the anti-interference capability of signal transmission can be further improved. The circuit board assembly adopts the epoxy glass cloth board with the characteristic impedance of 77 ohms, so that the stability and the consistency of signal transmission can be ensured. Moreover, a leakage protection function is realized by adopting a single-point grounding structure of the first coupling transformer, a discharge path is provided for common-mode noise, the safety and reliability of the isolation coupler can be improved, and meanwhile, a ground loop can be cut off and power frequency interference can be eliminated by adopting a single-point grounding structure of the second coupling transformer, so that the accuracy of signal transmission is improved.

The utility model belongs to the technical field of POE power supply equipment, and particularly relates to a POE system testing device which comprises a processing module, a port voltage detection module and a PSE testing module. The port voltage detection module is connected with the processing module and a port of the PSE; the PSE test module comprises a characteristic impedance test circuit and a load variable circuit, the characteristic impedance test circuit is connected with a port of the PSE power supply equipment, one end of the load variable circuit is connected with the characteristic impedance test circuit, and the other end of the load variable circuit is connected with the processing module; the test device can quickly identify a standard POE system or a non-standard POE system, can perform grading standard confirmation and actual output power confirmation on PSE power supply equipment, and is safe, reliable and low in cost.

The application provides a pad structure in a PCB and a method for optimizing the impedance of a pad in a PCB, and relates to the technical field of circuit board design. The pad structure comprises: a target pad formed on the PCB; a first transmission line electrically connected to the target pad, the line width of the first transmission line being smaller than the width of the target pad; a second transmission line electrically connected to the first transmission line, the line width of the second transmission line being smaller than the width of the target pad; and a third transmission line electrically connected to the second transmission line, the line width of the third transmission line being larger than the line width of the second transmission line. By setting the line widths of the first transmission line and the second transmission line to be smaller than the width of the target pad, a high-impedance thin line section is formed, and by utilizing the high characteristic impedance characteristic of the high-impedance thin line section, the capacitive low impedance of the wide pad itself can be effectively offset, so that the overall impedance of the pad area is improved without increasing the cost and process difficulty.

The utility model discloses a cable, which belongs to the field of cables and comprises a core wire, a middle coating layer, a first shielding layer, a second shielding layer and a ground wire, the middle coating layer is coated outside the core wire, the first shielding layer is coated outside the middle coating layer, the second shielding layer is coated outside the first shielding layer, and the ground wire is positioned between the middle coating layer and the first shielding layer. According to the cable provided by the utility model, through the combined action of multiple layers of structures, the middle coating layer, the first shielding layer and the second shielding layer can be dispersed to each layer when bearing external bending stress, so that the stress concentration of the core wire is reduced, the probability of deformation of the core wire due to repeated bending is reduced, the characteristic impedance stability is maintained, the signal transmission is ensured, and the data transmission abnormity is reduced.

The utility model discloses a communication cable for a solar photo-thermal power generation mirror field. The communication cable comprises a wire core combination unit, a first wrapping tape layer, a second wrapping tape layer, a shielding layer, an inner sheath, an isolating layer and an outer sheath which are sequentially arranged from inside to outside, the wire core combination unit comprises a cable core, a grounding wire core and a filling strip. The cable core comprises a tinned copper wire conductor and a solid silane crosslinked polyethylene insulating layer from inside to outside; the outer sheath is formed by extruding a halogen-free low-smoke flame-retardant polyolefin sheath material on the isolating layer; the solid silane crosslinked polyethylene insulating layer is uniformly extruded on the tinned copper wire conductor so as to ensure that the characteristic impedance of the cable is uniformly distributed. The cable is good in corrosion resistance, can adapt to severe environment conditions such as extreme temperature change, strong ultraviolet radiation and soil saline-alkaline property, is high in compression resistance and tensile strength, can adapt to direct burial laying requirements in complex terrains, is stable in characteristic impedance, guarantees the transmission efficiency of the cable, and is low in production and manufacturing cost.

The application provides an antenna assembly, an antenna and a communication device, and relates to the technical field of communication, to solve the problem of poor electrostatic discharge capability in a radiator. The antenna assembly provided by the application comprises a floor, a radiator and a grounding network, the radiator is used for radiating or receiving electromagnetic waves, the grounding network comprises a grounding end and a connecting end, the grounding end is connected with the floor, and the connecting end is connected with the radiator; the grounding network further comprises a resistive line and an inductive structure, and the resistive line and the inductive structure are connected between the grounding end and the connecting end. In the antenna assembly provided by the application, the resistive line has a relatively high characteristic impedance, thus, the working frequency or bandwidth and other performances of the radiator are not obviously affected, the inductive structure can conduct direct current and block alternating current, thus, the static electricity in the radiator can be discharged to the floor through the grounding network, and the grounding network can obviously block high-frequency radio frequency signals, so that the working performance of the antenna assembly is ensured.

The invention provides a probe structure and an inspection device capable of obtaining matching of characteristic impedance of a connection terminal as a signal circuit relay point. The present invention provides a probe structure for transmitting and receiving a high-frequency signal to and from an object to be inspected via a contact portion that electrically contacts an electrode of the object to be inspected, the probe structure being characterized by being provided with: a main body portion; a substrate holding part which is provided with a wiring substrate on one surface and is fixed on the main body part on the other surface; a connector that is joined to the wiring board of the board holding member and that connects the wiring of the wiring board and the coaxial cable via a connection terminal; and an impedance adjustment unit that adjusts a gap between the impedance adjustment unit and the connection terminal to perform impedance matching.

The application provides an anchor rod deformation monitoring structure based on cable sensing and a use method, and relates to the technical field of underground engineering monitoring.The anchor rod structure comprises an anchor rod body, a coaxial cable, a joint presser, a connector and a terminal load, the coaxial cable is provided with a distributed Fabry-Perot strain sensor, the coaxial cable and the anchor rod body are mutually bonded, one end of the coaxial cable is connected with the terminal load through an SMA joint connector, the other end of the coaxial cable is connected with a vector network analyzer through an SMA joint connector after being led out from an anchor rod tray, and the joint presser is arranged on the bonding section of the coaxial cable and the anchor rod and generates a characteristic impedance discontinuity.The anchor rod can be used for monitoring and analyzing the axial deformation, bending deformation and breakage of the anchor rod, realizes real-time monitoring of the axial deformation and bending deformation of the anchor rod without affecting the reinforcement effect of the anchor rod, and has the advantages of wide application range, resistance to high-temperature and high-pressure liquid environment, small transmission loss, high spatial resolution and the like.

The utility model relates to a high-frequency signal terminal, which comprises a body, a welding part and an inserting part, the welding part and the inserting part are fixedly connected to the two ends of the body respectively. A plurality of digging holes are formed in one end, close to the welding part, of the body. According to the high-frequency signal terminal provided by the utility model, the digging hole is arranged at one end of the body close to the welding part, so that the sectional area of the welding end of the high-frequency signal terminal is reduced, the capacitance is reduced, the characteristic impedance at the welding end is increased, the consistency with the characteristic impedance of a whole circuit is improved, and high-frequency signal transmission is facilitated. The high-frequency signal terminal provided by the utility model has the advantage of good signal transmission effect. The utility model also relates to a connector comprising the high-frequency signal terminal.

The invention discloses a concrete ultrasonic propagation characteristic modeling method and system, and relates to the technical field of ultrasonic non-destructive testing, and the method comprises the steps: obtaining the rheological behavior data of unsolidified cement slurry, building a concrete slurry fractional order viscoelastic constitutive model by adopting a Caputo type fractional order derivative, and obtaining a complex modulus; constructing a frequency domain wave equation by using the complex modulus, and calculating ultrasonic attenuation coefficients under different frequencies; dividing the concrete medium into thin layers along the propagation direction, and setting the thickness and characteristic impedance of each layer; a Waterman-Truell model is used to calculate a corrected complex wave number, and a structure factor is combined to correct scattering space correlation; calculating the total attenuation value of the attenuation coefficient of each thin layer, and establishing a propagation path total attenuation model. According to the method, the frequency response consistency is enhanced, the modeling precision of the heterogeneity and the multi-scale scattering characteristic of the concrete is improved, and the method has higher simulation accuracy and physical interpretation.

The application relates to the radio technology field, in particular to a radio frequency power amplifier and a wireless signal transmitting system. The radio frequency power amplifier comprises a first amplification branch and a second amplification branch. The first amplification branch comprises a first transistor. The gate of the first transistor is used for connecting a radio frequency output device to receive a radio frequency signal emitted by the radio frequency output device. The drain of the first transistor is used for connecting a signal transmitting device. The second amplification branch comprises a second transistor. The gate of the second transistor is used for connecting the radio frequency output device to receive the radio frequency signal emitted by the radio frequency output device. The drain of the second transistor is used for connecting the signal transmitting device. When the radio frequency power amplifier works, the working voltage of the drain of the second transistor is greater than the working voltage of the drain of the first transistor. The impedance of the first amplification branch in a backoff state, the characteristic impedance of a transmission line connected with the drain of the first transistor and the impedance of a combiner are equal, so that the bandwidth generated by the radio frequency power amplifier in the backoff state is ensured to be larger.