19 results about "Gain measurement" patented technology

A radio frequency antenna gain measuring apparatus includes: first and second antennas; antenna positioners to position the antennas; a central controller to: control the antenna positioners to position the first and second antennas, control the linear motion positioner to vary the separation distance, and receive information from the distance meter; and an antenna gain processor to: receive information from the central controller and the first and second radio frequency transmit and receive electronics device, and determine the gain of the first and second antennas based on the third-order scattered signal as a function of the separation distance.

The invention provides an SAR (synthetic aperture radar) satellite on-satellite real-time imaging processing load whole-satellite closed-loop test method, which comprises the following steps: generating orbit and attitude data by using a simulator, and determining observation time and observation wave position of an SAR load; an existing SAR image is used as a simulation scene target to generate a target backscattering coefficient; generating a radio frequency SAR echo signal by using the generated orbit, attitude and beam position and the generated target backscattering coefficient; the AD optimal level of echo sampling in an on-satellite SAR load receiver and the gain of an SAR central electronic equipment receiver are obtained; measuring antenna receiving gains of different wave positions from the antenna calibration network by using a vector network analyzer; measuring test cable loss from the antenna calibration network to the echo simulator; measuring echo power by using a high-speed oscilloscope according to the generated radio frequency SAR echo signals under different wave positions; calculating an MGC value set by the SAR load receiver corresponding to each echo; and connecting a test system, and carrying out real-time imaging processing, load imaging processing and image detection test.

The invention discloses a cable-free chip antenna impedance and gain measurement method, which comprises the following steps of: firstly establishing an electromagnetic model of a probe and a measured antenna, then establishing a free space propagation model based on a one-way transmission equation and a model of a measurement system, and then establishing an electromagnetic model of the measurement system comprising the probe, the free space propagation model and the measured antenna; the method comprises the following steps: firstly, deducing a complete electromagnetic model of a measurement system comprising any probe, free space propagation and any measured antenna, then determining scattering matrixes of the probe, the free space propagation and the measured antenna, and extracting antenna impedance and gain from near-field distance measurement; according to the invention, the influence of leakage current, scattering effect and the like of a traditional probe and a feed cable on a chip antenna is overcome, the method can be well applied to a scene in which a feed line has great influence on a measured antenna, and the measurement precision of the antenna is greatly improved.

The present invention discloses a device for measuring the temporal gain evolution and relaxation process of CO2 laser amplification, belonging to the field of laser technology. The device comprises: a continuous CO2 laser seed source, a short-pulse CO2 laser seed source, a first beam splitter located in the outgoing optical path of the short-pulse CO2 laser seed source; a pulsed CO2 laser information detection module located in the transmitted optical path of the first beam splitter; a first thin-film polarizer located at the intersection of the reflected optical path of the first beam splitter and the outgoing optical path of the continuous CO2 laser seed source; a CO2 laser amplifier, a second thin-film polarizer, a second beam splitter, a chopper wheel module, and a first mercury cadmium telluride detector located sequentially in the outgoing optical path of the first thin-film polarizer; and a time gating circuit for controlling the on / off timing of the continuous CO2 laser seed source, the short-pulse CO2 laser seed source, and the CO2 laser amplifier. This device simplifies traditional gain measurement devices while simultaneously studying various relaxation phenomena during the amplification process.

The invention discloses a multi-band multi-feed source focus shifting device and method for a GSO satellite parabolic antenna, and the device comprises a focus shifting fixed ring body which is provided with a plurality of feed sources, a transmission gear is engaged with an outer ring gear of the focus shifting fixed ring, and a control motor drives the focus shifting fixed ring to rotate through the transmission gear; wherein the ring surface of the focus-shifting fixing ring is perpendicular to the axial direction of the antenna, and when the feed source rotates along with the focus-shifting fixing ring, the center rotation path of the feed source passes through the focus of the antenna. According to the invention, through a mode of rotation control of the receiving feed source, measurement with highest gain at different frequency bands can be realized, measurement of ground weak electronic signals by a GSO satellite can be satisfied, results of non-specific targets, rapid discovery and positioning monitoring can be solved, and debugging of each frequency band and debugging of other frequency bands are ensured not to influence each other. The method has the advantages of rapidness, accuracy, convenience in assembly, easiness in expansion and the like.

This invention discloses a fully synthesized precision measurement unit for integrated circuit testing. The unit comprises a fully digital DAC module, a fully synthesized ADC module, and a gain measurement module. The fully digital DAC module is synthesized from a DDR-DDPM and LPF and is used to provide excitation for the device under test (DUT). The fully synthesized ADC is synthesized from a fully digital sub-DAC, a voltage comparator, and SAR logic and is used to read DUT data. The gain measurement module, comprised of analog components, provides gain and conversion between test vectors. This invention addresses the high cost of imported PMU chips, reduces capacitor parasitic effects, and improves accuracy.

A wireless communication device is provided with in-device capabilities for characterizing a coupling between a pair of antennas. The wireless communication device determines the coupling by operating gain measurements and by calibration gain measurements obtained through the test port.

Embodiments of the present disclosure relate to a loop gain measurement probe including a printed circuit board and an injection transformer. The loop gain measurement probe includes a first connection interface and a second connection interface, which are connected with the injection transformer and are connectable with a device under test. The loop gain measurement probe includes a first output and a second output, which are connectable to the test and / or measurement instrument. The loop gain measurement probe includes an input connected with the injection transformer and capable of forwarding an input signal received to the injection transformer. The loop gain measurement probe includes a first passive probe circuit and a second passive probe circuit, which are connected with the first connection interface and the first output as well as with the second connection interface and the second output, respectively.

The technical field of semiconductor laser threshold gain solution of the present invention discloses a method for solving the threshold gain of a semiconductor laser, including the following steps: according to the parameters related to the physical structure of the laser, the transmission coefficient is calculated through the transmission matrix; the longitudinal mode mode interval based on the FP cavity laser is calculated to determine multiple longitudinal mode modes; a loop body is constructed, and the scanning process of the loop body is performed in a longitudinal mode mode of the FP cavity laser using the dichotomy method, and the inner loop ends, and the threshold gain and lasing wavelength are extracted; an outer loop is executed, and the inner loop is executed in a new mode; the outer loop is repeatedly executed, and when the wavelength value is greater than the wavelength range set by the outer loop, the outer loop is terminated, and the threshold gain and lasing wavelength in each mode are output. The method disclosed by the present invention not only improves the speed and accuracy of the threshold gain measurement, but also can respond to the changes in the characteristics of the laser in real time, providing a more efficient and reliable tool for the design and optimization of semiconductor lasers.

This invention discloses a method for measuring the gain of a differential probe using a two-port vector network analyzer, comprising the following steps: calibrating the two-port vector network analyzer; constructing a differential test fixture; obtaining the S-parameters corresponding to the differential test fixture; obtaining the S-parameter matrix corresponding to a through-type calibration component; obtaining the S-parameter matrix corresponding to a line calibration component; obtaining the half-side transmission parameters of the differential test fixture; obtaining the differential-mode gain of the differential probe using the half-side transmission parameters of the differential test fixture and the S-parameters corresponding to the differential test fixture; replacing the differential test fixture with a common-mode test fixture, and obtaining the common-mode gain of the differential probe using the same method as steps S3 to S7. This method achieves voltage gain measurement of the differential probe in a balanced state, eliminating the measurement phase error caused by the offset between the measurement plane and the reference plane in traditional differential probe testing methods.

The application discloses a kind of antenna directional pattern measurement methods based on segmented gain variable threshold single-bit receiver, it is related to synthetic aperture radar radiometric calibration technical field.The method steps are as follows: the monotonic relationship of quantitative signal power and STR is analyzed, and quantitative model is established;The receiving signal amplitude reconstruction strategy of all sampling rate and SAR bandwidth ratio is constructed;The maximum amplitude and minimum amplitude of received signal are determined, the received signal amplitude is segmented and threshold is set;Signal spectrum is analyzed and quantitative signal power is estimated;STR and actual received signal power are calculated;Azimuth and range antenna directional pattern sample value are calculated, and according to radar equation, radar antenna azimuth and pitch gain is calculated, and antenna directional pattern is reconstructed using polynomial fitting.The application simplifies the structure of radar directional pattern gain measurement receiver, reduces the cost, guarantees the measurement accuracy, and can meet the demand of large-scale deployment and high-precision estimation of SAR radiometric calibration active receiver.

A wireless communication device includes a transmit (TX) chain, a loopback path, a receive (RX) chain, a power detector circuit, and a processing circuit. The TX chain generates a TX signal according to a digital TX input. The loopback path is coupled between an output node of the TX chain and an input node of the RX chain, and loops back the TX signal generated from the TX chain to output an RX signal to the RX chain. The RX chain receives the RX signal from the loopback path, and generates a digital RX output according to the RX signal. The power detector circuit performs power detection upon the RX signal at the input node of the RX chain to generate a power detection output. The processing circuit measures an RX gain of the wireless communication device according to at least the power detection output and the digital RX output.

The invention discloses a cable sheath tube density measurement method, which comprises the following steps of: 1, firstly, using a probe with an iron wedge block as a pipeline density measurement signal generation tool, and using a normal probe as a pipeline sound velocity measurement signal generation tool; 2, measuring the thickness of the pipeline by using a vernier caliper, and recording the thickness of the pipeline; 3, measuring the sound velocity of the pipeline; 4, performing gain measurement in water; 5, measuring the density of the pipeline; and 6, analyzing the data to obtain the density # imgabs0 # of the pipeline. According to the method, fast Fourier transform is carried out on multiple reflection echo signals of ultrasonic waves in an iron wedge block, the amplitude of the center frequency of each echo signal is extracted, data fitting is carried out under logarithmic coordinates, and the acoustic impedance of the pipeline can be obtained by combining the slope of a fitting curve with the multiple reflection theory, so that the initial calculation density of the pipeline is obtained; and then, combining parameters such as sound velocity and thickness of the pipeline, performing further accurate calculation by utilizing a multivariate quadratic model, and finally obtaining the density of the pipeline.

The invention specifically discloses an antenna pattern measurement method based on a segmented gain variable threshold single-bit receiver, and relates to the technical field of synthetic aperture radar radiometric calibration. The method comprises the following steps: analyzing a monotonic relationship between quantized signal power and STR, and establishing a quantitative model; constructing a received signal amplitude reconstruction strategy of all sampling rates and SAR bandwidth ratios; determining the maximum amplitude and the minimum amplitude of the received signal, segmenting the amplitude of the received signal, and setting a threshold value; analyzing the signal spectrum and estimating quantized signal power; calculating the STR and the actual received signal power; and calculating azimuth and distance antenna pattern sampling values, calculating azimuth dimension and pitching dimension gains of the radar antenna according to a radar equation, and reconstructing an antenna pattern by using polynomial fitting. According to the invention, the structure of a radar pattern gain measurement receiver is simplified, the cost is reduced, the measurement precision is guaranteed, and the large-scale deployment and high-precision estimation requirements of an SAR radiometric calibration active receiver can be met.

The invention discloses an antenna gain determination method and device, electronic equipment and a readable storage medium, and belongs to the technical field of antenna gain measurement. According to the method, electric field energy of a plurality of preset point locations on an equivalent virtual surface is acquired, and the equivalent virtual surface is determined based on a to-be-tested antenna; determining the total electric field energy of the equivalent virtual surface according to the electric field energy of the plurality of preset point locations; and on the basis of the total electric field energy of the equivalent virtual surface, calibrating the gain of the antenna to be measured, thereby effectively realizing accurate measurement on the gain of the antenna which carries out feeding through an air interface and comprises RIS.

The invention provides a non-interception type beam energy gain measurement method and system. The non-interception type beam energy gain measurement method is used for measuring the energy gain obtained when a beam passes through a radio frequency cavity, and the non-interception type beam energy gain measurement method comprises the following steps: obtaining the beam intensity Ib of the beam passing through the radio frequency cavity on line; acquiring beam power Pb of the beam absorbed from the radio frequency cavity; a beam energy gain delta W is calculated according to a beam energy gain formula, and the beam energy gain formula is shown in the specification, delta W is beam energy gain, Pb is beam power, and Ib is beam intensity. According to the non-interception type beam energy gain measurement method, the energy gain obtained when the beam passes through the radio frequency cavity can be measured in real time, the state of the radio frequency cavity can be represented more accurately, and the beam load effect can be quantized more accurately.

A system comprises a transceiver with at least one receive signal chain and at least one transmit signal chain. The receive signal chain may include an adjustable capacitive attenuator. An automatic gain control circuit may be designed to perform gain measurements in the receive signal chain and adjust the gain by modifying the attenuation at the adjustable capacitive attenuator.

The invention relates to the field of space remote sensing satellites, and provides a ground vacuum calibration test method based on a multi-channel transceiver module, which comprises the following steps: determining a calibration loop power parameter and a link gain parameter based on an internal calibration loop gain formula, and establishing a relation model between each parameter and an internal calibration coefficient k; configuring a multi-channel transceiver module; starting a test, collecting calibration loop power parameters and link gain parameters output by the tested equipment in real time, and synchronously recording environmental conditions during the test; and calculating an internal calibration coefficient k based on the acquired calibration loop power parameter, and calculating a corresponding link gain parameter. By accurately measuring transmitting power, receiving gain and calibration loop power parameters, high-precision gain measurement can be realized under complex environmental conditions, an accurate internal calibration coefficient is generated, and radiation calibration gain compensation of a satellite-borne system is supported.

These images display measured data from a vibrometer that measures the acceleration, velocity, displacement, etc. of various industrial equipment. As shown in each image, the measurement value display bar displays the current measurement value, and the length of the bar changes depending on the actual measurement value. The danger value display bar displays the danger value range that the user has set in advance. The user can set any gain for the signal to be measured, and the position of the measurement value upper limit indicator changes depending on the gain setting. The user can adjust the gain while observing the current measurement value to prevent the measurement value from reaching the danger range.