277 results about "Standing wave ratio" patented technology

The embodiment of the invention provides a closed-loop control method for power driving and protection, and the method comprises the steps: constructing a voltage feedback type circuit through a high-speed operational amplifier, and forming a closed-loop gain structure through a feedback network of the voltage feedback type circuit; the load current of the output end of the voltage feedback type circuit is monitored in real time, and when the load current exceeds a first set threshold value, a protection mechanism is triggered to turn off the output stage; the power-on surge current is limited through the soft start control circuit; phase information of a load reflection coefficient is obtained, an inductance / capacitance combination of the variable dynamic impedance matching network is selected according to phase information table look-up, inductance / capacitance parameters are switched through a relay, and the transmission standing-wave ratio between the power amplifier and a load is optimized; monitoring the temperature of the radiating fin of the power tube, and dynamically adjusting the resistance value of the feedback network; and performing cooperative control of short-circuit protection, over-temperature protection and surge suppression according to the priority. According to the embodiment of the invention, the performance bottleneck in a load fluctuation scene is broken through.

The invention belongs to the technical field of antenna engineering, and particularly relates to an ultra-wide-band low-profile phased-array antenna, which realizes broadband impedance matching characteristics and effectively expands the working bandwidth of the antenna by optimizing a dipole arm structure and introducing a matching branch knot and linear tapered slot composite structure on a radiation unit layer; on the array architecture level, an electromagnetic metasurface technology is adopted, array current distribution is improved through a periodic artificial electromagnetic structure, the active standing-wave ratio is remarkably reduced, the scanning angle of an array is widened, and meanwhile high compression of a system profile is achieved; on the structural design level, a three-dimensional composite structure of a transverse metal floor, a longitudinal radiation layer and a transverse metasurface layer is innovatively constructed, and the overall section height is reduced to 0.137 lambda Low (lambda Low is the lowest working frequency wavelength) through electromagnetic coupling and space folding technologies; in conclusion, the ultra wide band (the relative bandwidth is greater than or equal to 90%) and the low profile (lt; and the method is suitable for a new generation of broadband phased array radar system.

The invention relates to a 5G communication antenna electromagnetic compatibility enhancement method, device and equipment, and belongs to the technical field of wireless communication networks, and the method comprises the steps: collecting frequency band-space electromagnetic intensity data in real time through a distributed sensor network, and constructing a three-dimensional mapping model in combination with base station beam parameters and polarization information; interference frequency band coordinates are screened based on the model, a phase gradient compensation value is calculated by using a polarization mismatch degree, an antenna array is driven to reconstruct a radiation pattern, and polarization orthogonal nulling is formed in an interference area; the port standing-wave ratio is synchronously monitored, closed-loop optimization is triggered, the antenna weight and the polarization direction are dynamically adjusted until indexes converge, and the problems of insufficient dynamic interference suppression precision, polarization mismatch compensation lag and the like in the prior art are solved.

The invention is suitable for the technical field of communication, and particularly relates to a method for detecting mismatched harmonic waves of a power amplifier. The method comprises the steps that a first power detection unit is connected with a coupler through a control unit, the standing-wave ratio of a to-be-detected power amplifier chip is adjusted to be 1: 1 through a tuner, and the power of an input signal of a vector signal generator is adjusted till the target power of the to-be-detected power amplifier chip is reached; the second power detection unit is connected with the coupler through the control unit, the output standing-wave ratio of the to-be-detected power amplifier chip is adjusted to a preset specific value through the tuner, and when the tuner modulates phases at intervals of preset degrees, the harmonic power of the to-be-detected power amplifier chip in each phase is recorded through the second power detection unit. Compared with the prior art, the method can accurately test and evaluate the harmonic wave of the to-be-tested power amplifier chip under the mismatched standing wave condition, thereby evaluating the harmonic wave index of the to-be-tested power amplifier chip.

The invention discloses a broadband single-pole double-throw switch MMIC, and belongs to the field of radio frequency / microwave. The switch adopts a symmetrical dual-channel structure, each channel comprises an input end series switch circuit, an output end series switch circuit and two parallel switch branches, channel switching is realized through two complementary control voltages, and impedance matching is carried out between the circuits by adopting microstrip lines. According to the technical scheme, switching tubes, resistors and inductors are utilized to form a circuit network, and a signal transmission path is optimized through the resonance effect of the inductors and switching tube cut-off capacitors in parallel branches in combination with a resistor parallel structure and a microstrip line matching technology. According to the invention, the performance of low insertion loss and high isolation in a broadband is achieved, the voltage standing wave ratio of an off-state output port is reduced, the port matching capability is improved, and an efficient and stable solution is provided for signal routing in a radio frequency system.

The invention belongs to the technical field of antennas, and relates to a common-caliber dual-polarization tight coupling array antenna capable of wide-angle scanning, which comprises a low-frequency antenna array surface, a low-frequency vertical branch knot, a low-frequency feed balun, a high-frequency antenna array surface, a low-frequency feed network and a coaxial connector. According to the invention, a traditional ultra-wideband tight coupling array antenna is decomposed into two antennas with small bandwidths, and loading of resistive materials is avoided through common-caliber configuration. Wherein an upper-layer low-frequency antenna unit is divided into a plurality of sub-units, electromagnetic transparency of a lower-layer high-frequency antenna is realized by adopting a winding line design, mutual interference of high and low frequencies is further inhibited by loading a vertical branch knot, and the fractal low-frequency sub-units are synthesized into a large unit through a power divider. According to the dual-polarization ultra-wideband antenna, the average efficiency reaches 85% in the working frequency bands of 2-6GHz and 7-18GHz, the active standing-wave ratio is smaller than 4 in the scanning range of + / -60 degrees, and the problem that in a traditional design, ultra-wideband, high efficiency, wide-angle scanning and dual polarization cannot be achieved at the same time is solved.

The invention belongs to the field of antenna quality detection, relates to a data analysis technology, is used for solving the problem that the electrical parameter performance of an antenna cannot be tested and analyzed in the prior art, and particularly relates to a dual-notch ultra-wideband antenna quality detection method and system. Comprising an electrical parameter test module, an environment adaptation test module and a comprehensive evaluation module which are connected in sequence, and the environment adaptation test module is further in communication connection with an adaptation optimization module; the electrical parameter test module is used for testing and analyzing electrical parameters of the antenna; the antenna is marked as a test object, and the test object is marked as an electrical parameter normal object or an electrical parameter abnormal object through a voltage standing wave ratio; according to the invention, the environmental adaptability of the antenna can be tested and analyzed, the electrical parameter performance of the single antenna is verified again according to the generated test environment, and the environmental adaptability of the batch of antennas is evaluated according to the proportion of the number of adaptive qualified objects in the verification result. And triggering adaptive optimization analysis when the environmental adaptability is abnormal.

The invention belongs to the technical field of electronic information, and discloses a millimeter wave magnetic coupling variable resonant equalizer, which comprises a transmission waveguide channel, a coupling channel and a resonant cavity which are communicated, the resonant cavity and the coupling channel are arranged in the narrow side direction of the transmission waveguide channel, the opening direction of the coupling channel is parallel to the direction component of an electric field, and the opening direction of the coupling channel is parallel to the direction component of the electric field. The inner walls of the two ends of the resonant cavity are adjustably and slidably connected with adjusting blocks, the opposite inner side faces of the two adjusting blocks are fixedly connected with wave absorbing materials, and the inner wall, facing the coupling channel, of the resonant cavity is detachably and movably connected with a guide block. The center position of the resonant cavity is provided with a telescopic tuning pin perpendicular to the direction component of the magnetic field. According to the structure, the processing and installation problems of a common waveguide equalizer are effectively solved, the equalizer is debugged more simply and quickly, meanwhile, the standing-wave ratio is optimized by changing the cavity structure, and a relatively complex gain curve can be equalized through the good frequency response characteristic.

The invention provides a broadcast antenna ATU input standing-wave ratio automatic adjusting and testing system. A human-computer interface is used for setting a target working program, a working frequency band and initial inductance and capacitance values, and a tuned standing-wave ratio curve and inductance and capacitance values are displayed; the control module decomposes the input initial inductance and capacitance values into rotation turns required by the current motor, transmits the rotation turns to the transmission module, and sends a target working program to the original short-wave antenna system; the transmission module enables the motor to be located at a target position, and correspondingly, target inductance and capacitance values are achieved; the data acquisition module is used for testing the standing-wave ratio of the system, reading the current inductance and capacitance values, recording the maximum value of the standing-wave ratio and sending the maximum value to the data processing module; and the data processing module processes the data and judges whether the current standing-wave ratio meets the requirement or not. According to the method, the automatic test system and the automatic optimization algorithm are combined, so that the workload of debugging personnel is reduced, and the working efficiency of ATU tuning is improved.

The invention relates to the technical field of radio frequency circuits, and provides a protection circuit, method and module of a radio frequency front-end circuit and a radio frequency device.The protection circuit comprises a bidirectional power detection module which is connected in series in a link from a power amplifier of the radio frequency front-end circuit to a radio frequency output end; the comparison trigger module is connected with the bidirectional power detection module; and the power control module is connected with the comparison trigger module and the power amplifier. The bidirectional power detection module detects forward power and reverse power of a link to form a first signal and a second signal, and the comparison trigger module performs comparison processing according to the first signal and the second signal and generates a trigger signal when the output power is too large or the standing-wave ratio is too large. And the power control module adjusts the output power of the power amplifier according to the trigger signal, so that negative effects on circuit elements caused by overlarge output power or overlarge standing-wave ratio are avoided, the circuit elements are protected from being damaged, high-precision protection on the radio frequency front-end circuit is realized, and the safety and the reliability are improved.

The invention relates to a radio frequency coaxial connector with an automatic compensation structure. The radio frequency coaxial connector is used for direct insertion-screwing tool-free field installation of a smooth copper-clad aluminum pipe radio frequency cable. The connector shell is composed of a rear threaded shell body, a middle threaded shell body and a front threaded shell body, a blind hole is formed in the rear portion of the inner conductor, and the core wire can float in the hole to avoid crushing. According to the radio frequency coaxial connector with the automatic compensation structure, the rear portion of the inner conductor is supported by means of the two insulation supports of the insulation assembly, and in the process that the cable core wire is inserted into the insertion hole of the inner conductor, the cable core wire is inserted into the insertion hole of the inner conductor. Impedance can be automatically compensated, so that impedance matching of a product is guaranteed, and the voltage standing-wave ratio is reduced; and the insulation support of the product is not an inverted cone type tightening structure in the prior art, but clamps the cable core wire in a sliding manner, so that the stress of the connector insulator adopting the structure is relatively small, and the situation that the inner conductor cannot tighten the cable due to deformation is avoided.

The invention discloses a rectangular waveguide sealing window structure for realizing broadband transmission, which belongs to a microwave signal detection device and comprises a first rectangular waveguide cavity, a second rectangular waveguide cavity and a rectangular dielectric block arranged between the first rectangular waveguide cavity and the second rectangular waveguide cavity, the first rectangular waveguide cavity comprises a first rectangular waveguide shell and two first stepped transition structures embedded into an inner cavity of the first rectangular waveguide cavity, and the second rectangular waveguide cavity comprises a second rectangular waveguide shell and two second stepped transition structures embedded into the second rectangular waveguide shell. The opposite side faces of the two first stepped transition structures and the two second stepped transition structures are provided with identical tooth-shaped steps, the second rectangular waveguide shell is further internally provided with an installation cavity communicated with the second I-shaped sliding groove, the two waveguide cavities are connected through screws, and the rectangular dielectric block is fixedly installed in the installation cavity. The vertically symmetrical multi-stage stepped impedance matching network provided by the invention realizes excellent transmission performance with low voltage standing-wave ratio in a wide frequency band, and is suitable for a millimeter wave system with high power and wide frequency band.

The invention discloses a radio frequency power amplifier, a radio frequency power amplifier module and a radio frequency power amplifier module, and the radio frequency power amplifier comprises a four-stage power amplifier structure which is used for amplifying an input signal to preset output power; the inter-stage matching network is used for completing impedance matching between the output impedance of each stage of array and the output impedance of the rear-stage array and impedance matching between the input impedance of each stage of array and the output impedance of the front-stage array through an impedance matching technology; the protection circuit comprises a temperature protection unit and a standing-wave ratio protection unit. The temperature protection unit is used for monitoring the temperature of the GaN power amplifier unit in each array in real time and comparing the temperature with a preset temperature, and generating a logic instruction for cutting off the power supply of the corresponding array when the number of overtemperature units is judged to be greater than a preset number; the standing-wave ratio protection unit is used for detecting the output standing-wave ratio and generating a logic instruction for switching power supply when it is judged that the detected standing-wave ratio is larger than a preset ratio. According to the invention, high-performance communication requirements and simple and effective exception protection can be met.

The utility model provides an ultra-wide-band high-performance array antenna, which comprises a plurality of ultra-wide-band oscillator units arranged on a reflecting substrate in an array form, the ultra-wideband oscillator unit comprises a plurality of radiation parts arranged on the dielectric plate at intervals, and the radiation arm of any radiation part and the radiation arm of the adjacent radiation part are collinear to form a dipole; in one radiation piece, any two adjacent radiation arms are perpendicular to each other to form a dual-polarized oscillator; the ultra-wideband oscillator unit further comprises a parasitic branch knot. The parasitic branches are arranged between every two radiation pieces, and the parasitic branches are arranged on the dielectric plate in the horizontal direction and the vertical direction; the radiation part and the parasitic branch knot are coupled and connected to form a frequency expanding structure. According to the utility model, the S parameter of the oscillator unit is optimized by arranging the coupling frequency-broadening structure and the parasitic branch knot, electromagnetic waves are guided through the cooperation of the reflecting strip, the isolating strip and the director, the interference of high frequency to low frequency is reduced, the standing-wave ratio of the antenna is further reduced, and the directivity of the antenna is improved.

The embodiment of the invention is suitable for the technical field of communication, and provides an antenna connection state detection circuit and method, and the detection circuit comprises an adjustable attenuation module which is used for carrying out the power attenuation of a first radio frequency signal and a second radio frequency signal according to an attenuation coefficient, and obtaining a first attenuation signal and a second attenuation signal; the power of the first attenuation signal and the power of the second attenuation signal are both within the power detection range of the detection module; the detection module is used for detecting a first voltage value corresponding to the first attenuation signal and a second voltage value corresponding to the second attenuation signal; and the control module is used for calculating the standing-wave ratio of the signal transmitting module according to the first voltage value, the first power attenuation, the second voltage value and the second power attenuation. According to the detection circuit provided by the embodiment, the application range of the antenna connection state detection method can be expanded, and the accuracy of antenna connection state detection is improved.

The invention, which relates to the technical field of modern communication, discloses a metasurface-based high-gain low-profile dual-circularly polarized antenna comprising a first dielectric plate, a second dielectric plate arranged below the first dielectric plate, and a metasurface structure arranged above the first dielectric plate. Three rows and three columns of periodically arranged metasurface structures are arranged above the first dielectric plate, a multi-level cooperative working mechanism is constructed by combining 45-degree symmetrical composite gaps etched in a layer indirect floor and a microstrip feeder line which is orthogonally arranged on the lower layer, and the metasurface array realizes high-gain radiation by regulating and controlling the phase of electromagnetic waves. The composite slot structure efficiently converts microstrip line energy into an orthogonal degenerate mode through non-contact coupling, circular polarization purity is guaranteed, the axial ratio bandwidth is expanded to 24.2%, an orthogonal microstrip feeder line forms a 90-degree phase difference through accurately controlled size, high isolation and stable standing-wave ratio of double ports are guaranteed, and the antenna has a wide application prospect. And finally, dual-circular-polarization independent radiation is realized in a 5mm low-profile structure.

Provided is a radio transmitter test system that enables accurate measurement of reflected wave power of an antenna. A radio transmitter test system includes: a power amplifier that amplifies power of a high-frequency signal from a signal generator; a simulative antenna for which a voltage standing wave ratio is variable and that is connected to a coaxial cable in place of an antenna; a directional coupler that is connected between the power amplifier and the simulative antenna, couples the high-frequency signal to the simulative antenna, and outputs traveling wave power and reflected wave power between the power amplifier and the simulative antenna; a power meter connected downstream of the directional coupler; and a control device, wherein the control device calculates, for each voltage standing wave ratio of the simulative antenna, a correlation coefficient indicating a correlation between traveling wave power and reflected wave power of the simulative antenna and traveling wave power and reflected wave power measured by the power meter, and calculates reflected wave power of the antenna by correcting, with the correlation coefficient, the traveling wave power and the reflected wave power measured by the power meter in a state where the simulative antenna is replaced by the antenna.

The invention relates to the technical field of noise filtering, in particular to an electronic circuit with a transmission line type noise filter, and the electronic circuit comprises a frequency determination device which is used for determining the working frequency and voltage of the electronic circuit; the device determining device is used for selecting a microstrip line as a transmission line and optimizing the filter by using a composite right / left hand transmission line and an open-circuit T-shaped structure; the impedance matching device is used for matching the impedance of the filter with the impedance of the transmission line; the matching measuring device is used for measuring the impedance matching effect by using a reflection coefficient and a VSWR (Voltage Standing Wave Ratio); and the software simulation device is used for simulating and optimizing the matched filter and transmission line by using simulation software. According to the invention, the impedance of the filter is matched with the impedance of the transmission line, so that the impedance change of the signal in the transmission process is reduced, the reflection of the signal is reduced, and the transmission quality and efficiency of the signal are improved.

The invention relates to the technical field of coupler design, in particular to a bi-directional coupler applied to a high-frequency RFID (Radio Frequency Identification Device) system, which comprises the following steps: S1, respectively constructing a series transformer, a parallel transformer and a Magic-T structure hybrid network, and forming an impedance self-matching coupler core framework by adopting a plurality of Ni-Zn ferrite double-hole magnetic rings; s2, inputting an original coupling signal output by the coupler core architecture into a phase-amplitude cooperative calibration module to generate a calibrated stable coupling signal; s3, inputting the stable coupling signal into a bridging T-type attenuation network group, respectively performing accurate power adjustment on a forward coupling path and a reverse coupling path, and finally outputting a high-directivity and low-fluctuation coupling signal; s4, monitoring the impedance state of an antenna port in real time, and feeding back and adjusting a matching network structure to realize stable control of the standing-wave ratio in a full frequency band range; according to the invention, the design of an external matching circuit is simplified, the coupling efficiency and directivity are improved, and the method has important engineering value.

The utility model discloses a real-time vector detection device based on a radio frequency signal short-wave antenna tuner, which comprises a radio frequency signal sampling module, an AGC, an AD and an FPGA, the sampling input end of the radio frequency signal sampling module is connected with a radio frequency path, and the output end of the radio frequency signal sampling module is provided with a forward signal end and a reverse signal end and is connected to the AGC; the AGC can perform gain attenuation processing on an input forward signal and an input reverse signal, an output end of the AGC is provided with a forward signal end and a reverse signal end which are respectively connected to a sampling input end of the AD, the AD is a dual-channel over-sampling analog-to-digital conversion module, an output end of the AD is connected with the FPGA, an input clock of the FPGA is 100MHz, the DDS is realized by adopting an IP core design, the FPGA can realize sampling, calculation and frequency mixing, and the FPGA is connected with the FPGA. And the matching network is controlled to realize tuning and system protection or alarm according to the calculated impedance value and standing-wave ratio. According to the utility model, the hardware circuit is simplified, the power standing-wave ratio condition of the access can be detected in real time, the detection efficiency is improved, the use is convenient, and the detection is efficient and accurate.

The invention relates to an automatic switching device for antennas of train dispatching main and standby stations and an implementation method. The device comprises a radio frequency interface, a radio frequency switch, a directional coupler, a detector, a microcontroller and an LED indicating lamp, the radio frequency interface I is connected with an antenna, the radio frequency interface II and the radio frequency interface III are respectively connected with a main station platform and a standby station platform, and the radio frequency switch realizes automatic switching between the antenna and the main station platform and the standby station platform under the control of the microcontroller. The directional coupler and the detector are used for collecting forward and reverse power of a transmitted signal, and the microcontroller calculates a standing-wave ratio according to detection voltage and performs threshold judgment. The method comprises the steps that after the device is powered on, the default antenna is communicated with the master station, and when it is detected that standby station transmitting signals meet a threshold, the standby station is automatically switched to; and if the signals of the standby station are insufficient, the master station is kept working, and indication and alarm are carried out through an LED. The device realizes rapid and automatic switching between the main station and the standby station, reduces the communication interruption time, and effectively improves the reliability and the operation and maintenance automation level of a communication system.

The utility model discloses an improved medium-wave multi-order deploying network, which belongs to an antenna deploying facility and comprises a first-order tuning unit and a second-order tuning unit. The first-order tuning unit comprises a first inductance coil and a second inductance coil which are connected in parallel and grounded, the second tuning unit comprises a third inductance coil and a fourth inductance coil, the first-order tuning unit and the second-order tuning unit are designed in the network, the broadcast frequency working bandwidth can be widened, and when the standing-wave ratio is smaller than or equal to 1.2, the frequency of the broadcast frequency can be increased. And the debugging bandwidth is 3 times of the bandwidth of the traditional inverted L-shaped, T-shaped or pi-shaped single-loop deploying network, and the broadcasting requirement of the future technical development of medium waves can be met.

The utility model discloses a microwave radar receiver protection structure and method, the microwave radar receiver protection structure comprises a cascade amplitude limiter, the cascade amplitude limiter is arranged behind an antenna sum-difference device, and the cascade amplitude limiter is arranged in front of a receiver radio frequency front end circuit. The cascade amplitude limiter comprises a waveguide plasma amplitude limiter, a micro-strip amplitude limiter and a waveguide coaxial converter, the micro-strip amplitude limiter is cascaded behind the waveguide plasma amplitude limiter, and the waveguide coaxial converter is cascaded behind the micro-strip amplitude limiter. The starting threshold of the micro-strip amplitude limiter is effectively improved compared with the working threshold of other amplitude limiters, so that echo signals can enter a receiver with low loss, and the sensitivity of the receiver is ensured. According to the cascade amplitude limiter, the standing-wave ratio near the working frequency is slightly larger than 1, the loss is low, and the use requirement is met. According to the utility model, two stages of amplitude limiters with different forms are used, so that the high power resistance and the fast response time are improved; a micro-strip amplitude limiter is used to raise a starting threshold.

The invention relates to the field of ultrasonic near-field suspension, in particular to a standing-wave ratio adjusting method suitable for annular vibration flat plate traveling waves, and the method comprises the steps: determining the mechanical resonant frequency in a longitudinal vibration mode required by an ultrasonic suspension transmission device; respectively applying two paths of excitation signals with the same mechanical resonant frequency to the transducer 1 # and the transducer 2 #; analyzing the vibration displacement A of each point on the annular vibration flat plate, and calculating the change condition of the vibration displacement A of each point on the annular vibration flat plate along with theta and time t when the mounting angles of the transducer 1 # and the transducer 2 # are theta, so as to obtain the theta value in a pure traveling wave state under a constant condition; and changing the phase difference theta of the two paths of excitation signals, obtaining the phase difference theta of the excitation signals when the amplitudes of all points on the annular vibration flat plate are equal, solving the actual installation angles of the current transducer 1 # and the transducer 2 # according to the mathematical relationship of the theta sum, adjusting the phase difference theta of the two paths of excitation signals, and obtaining the determined standing-wave ratio.

The invention discloses a radio-frequency coaxial cable working at an ultra-cut-off frequency and a preparation method of the radio-frequency coaxial cable. The coaxial cable provided by the invention sequentially comprises an inner conductor, a foaming insulating layer and an outer conductor from inside to outside, the inner conductor and the outer conductor are coaxially nested; the outer conductor is an embossed copper pipe; the foaming insulating layer is made of foaming polyethylene; the foamed polyethylene is manufactured by physical foaming by adopting hexafluorocyclobutane as a foaming agent, a closed-cell structure with the closed-cell rate larger than 90% and the pore size of 10-100 microns is formed, and the outer conductor and the foamed insulating layer are subjected to heat treatment at the temperature of 80-125 DEG C to induce secondary pore growth. According to the invention, by utilizing the principle of secondary growth of bubbles, the phenomena of stress accumulation and nonuniform air holes caused by the fact that bubble tissues of the foaming insulating layer are pressed in the embossing process of the outer conductor are improved, scattering and reflection of signals are reduced, and the cable can still keep excellent standing-wave ratio performance in an adjacent wave band exceeding a cut-off frequency; therefore, the 5G communication requirement of the large-size coaxial cable with the wave band of 2.7 G to 3.3G is met.

The invention relates to the technical field of microwaves, in particular to a broadband antenna matching system based on a 4: 1 impedance conversion balun, which comprises the 4: 1 impedance conversion balun, an adjustable impedance matching network, a radio frequency monitoring unit and a logic control unit, the logic control unit is configured to receive forward power and reflection power signals and calculate to obtain a standing-wave ratio or a reflection coefficient under a current working frequency point; comparing the standing-wave ratio or the reflection coefficient with a preset threshold value; based on a comparison result, executing an adaptive matching algorithm, and iteratively generating and outputting a new digital control signal to drive a variable reactance element in the adjustable impedance matching network to change the value of the variable reactance element; and through closed-loop feedback control, the impedance of the adjustable impedance matching network is dynamically optimized. By modifying an algorithm parameter or a lookup table in the logic control unit, the same hardware platform can easily adapt to antennas with different impedance characteristics and different frequency bands. And the design flexibility and the product universality are greatly enhanced.

This invention provides an automatic tuner for a loop antenna used in shortwave communication, belonging to the field of shortwave communication technology. This tuner aims to solve the problems of existing automatic tuners for loop antennas, such as difficulty in balancing versatility and high power performance, and poor high-voltage withstand capability. The tuner includes: a matching circuit, which includes couplers for shunting forward and reverse radio frequency signals; a tuning actuator, which includes an oil-immersed variable capacitor and a drive mechanism; and a main control circuit. Based on the signal shunted by the coupler, the main control circuit autonomously calculates the standing wave ratio (VSWR) and generates a control signal to control the matching circuit and tuning actuator independently of the radio transceiver, thus completing automatic tuning. This invention improves voltage withstand and power handling capability by using an oil-immersed variable capacitor, and achieves universal tuning through the autonomous control of the main control circuit, overcoming the shortcomings of existing technologies and offering the advantages of high power, high reliability, and strong versatility.

The invention discloses a voltage standing wave ratio measuring method and device, and relates to the technical field of electronic information, and the method comprises the steps: transmitting a transmitting signal, the transmitting signal comprises a training sequence, the training sequence comprises at least one symbol transmitted at full power, the full power comprises that the difference between the full power and the calibration power of a baseband signal is not greater than a first threshold value, and therefore, the difference between the full power and the calibration power of the baseband signal is not greater than the first threshold value; the power of the target emission signal collected based on the training sequence is not very small, so that the accuracy of a measurement result and the stability in a complex scene are improved.

The invention discloses a method and equipment for improving matching of a measured piece in an attenuation measurement system, belongs to the field of radio metering, and comprises the method for improving matching of the measured piece in the attenuation measurement system, and the core of the method is that a precise matching absorption load is added in a front-end transmission system of the measured piece; energy transmission is realized on a waveguide wide side of the precise matching absorption load through a coupling hole; a transmission waveguide is additionally arranged above the coupling hole, and energy is transmitted to a measured piece in the forward direction; and a precise matching absorption load is added in the reverse direction to absorb energy in the reverse direction, so that the measured piece matching improvement equipment in the attenuation measurement system is formed, and finally the measured piece matching of the attenuation measurement system is improved. According to the method and the equipment, the impedance matching of the measured piece is improved by using the precise matching load, the voltage standing-wave ratio of the load level is realized, and the attenuation measurement accuracy is improved. The tested piece matching improvement equipment developed by using the method is directly connected to two ends of the tested piece in an attenuation measurement system, so that the impedance matching of the tested piece is improved.