12 results about "Linearity testing" patented technology

The invention discloses a light source system capable of continuously adjusting an attenuation ratio, and belongs to the technical field of optical radiation measurement and photoelectric detection. In order to solve the problems of wavelength dependence, discontinuous adjustment, spectrum distortion and the like existing in an existing light intensity adjusting scheme, a combined structure of an integrating sphere and a diaphragm cylinder is adopted, and the device comprises a light source, the integrating sphere with the high-reflection inner wall, a front-end adjustable diaphragm, the diaphragm cylinder with the extinction inner wall and a rear-end adjustable diaphragm. Continuous attenuation of output light intensity in a predetermined dynamic range is realized by adjusting the apertures of the front and rear diaphragms, the lower limit of attenuation ratio meets the requirement, and the dynamic range can reach more than three orders of magnitude. The system uses the integrating sphere to form a stable Lambert light source, the attenuation process depends on geometric parameters, spectral distribution and spatial uniformity basically remain unchanged, and the non-uniformity of a light-emitting surface is not greater than 5%. The invention further provides a calibration method, high-precision attenuation prediction is achieved through detector measurement and view factor model fitting, and the calibration method is suitable for weak cursor calibration, detector linearity testing and other applications.

The embodiment of the invention provides a non-linearity testing device and method, and the device comprises the steps: the non-linearity testing device is used for testing the non-linearity of a chip of the same type as the testing device, and a frequency mixing module in the non-linearity testing device is used for obtaining a radio frequency signal which is transmitted by a to-be-tested chip and is received by a receiving module, performing frequency mixing processing on the radio frequency signal to obtain an intermediate frequency signal; the conversion module is used for performing analog-to-digital conversion on the intermediate frequency signal to obtain a digital signal; the processing module is used for performing frequency domain transformation on the digital signal to obtain frequency spectrum data, determining main signal frequency point power and stray power according to the frequency spectrum data, further calculating a nonlinear value, and calibrating the to-be-tested chip according to the nonlinear value so as to enable the to-be-tested chip to work in a linear region, thereby solving the problems that an existing chip nonlinearity test depends on external equipment, the cost is high, and the test precision is high. And the test efficiency is low.

This invention discloses a calibration system and method for extremely weak light radiance based on a cascaded integrating sphere, belonging to the field of optical radiation metrology and photoelectric detection technology. The system includes a first integrating sphere, an aperture tube, and a second integrating sphere. The aperture tube achieves large dynamic range light intensity adjustment through geometric attenuation. The second integrating sphere connects both a reference detector and a high-sensitivity detector to be calibrated, enabling online calibration and dynamic range bridging under the same radiance field. By adjusting the aperture, the light flux distribution is controlled, allowing the measurement ranges of the two types of detectors to overlap. This is used to perform correction processing related to non-ideal effects of single-photon detectors and high-precision measurement of extremely weak light radiance. This invention features a compact structure, stable and reproducible attenuation, and is suitable for weak light calibration and linearity testing in fields such as quantum optics and nighttime remote sensing.

The application discloses a kind of receiver power linearity testing device and method, the device includes signal source, single-pole double-throw radio frequency switch S1 and S2, amplifier A1, A2 and A3, power divider, power meter, program-controlled step attenuator T1, T2, T3 and T4 and measured receiver, the signal source is connected single-pole double-throw radio frequency switch S1, the first output of single-pole double-throw radio frequency switch S1 is sequentially connected amplifier A1 and program-controlled step attenuator T1, its second output is sequentially connected amplifier A2 and program-controlled step attenuator T2, program-controlled step attenuator T1, T2 respectively connect the first input and second input of single-pole double-throw radio frequency switch S2, its output end is connected the input of power divider, the first output of power divider is connected power meter, its second output is sequentially connected amplifier A3, program-controlled step attenuator T3, program-controlled step attenuator T4 and measured receiver.The application compared with traditional testing method, test precision is high, test dynamic range is big.

The application discloses a kind of silicon-based mach-zehnder modulator optimal linear point search method.The method is according to the power estimation of the fundamental component and third-order intermodulation component of modulator output signal to estimate the linearity of corresponding operating point, and the optimal linear point of the modulator can be obtained based on the maximum estimated value of linearity. The method uses maximum entropy spectrum subtraction to reduce the noise floor of the signal, and uses brute force search method to search for the optimal combination of the phase difference between the upper and lower arms of the modulator and the reverse bias voltage to obtain the optimal operating point. Compared with the linearity obtained by setting the modulator operating point to the quadrature point in the conventional linearity test method, the optimal linear point searched by the method can significantly improve the linearity of the modulator, which is beneficial to realize high linearity silicon-based integrated microwave photonic system.

The invention relates to the technical field of infrared focal plane detection, in particular to a detector output voltage nonlinearity test method, which comprises the following steps of: setting a detector to image a preset black body; respectively acquiring an output voltage value and an area array output voltage mean value of each pixel of the detector under the first preset effective integration time and the second preset effective integration time, and calculating a first correction coefficient and a second correction coefficient of each pixel through a two-point correction formula; obtaining an output voltage value of each pixel of the detector in a third preset effective integration time, and calculating a correction voltage value of each pixel and an area array correction voltage mean value; performing plane fitting according to the correction voltage values of all the pixels of the detector, calculating the residual root mean square of the correction voltage values of all the pixels of the detector and the corresponding fitting voltage values in the fitting plane, and calculating the nonlinearity of the area array voltage value curved surface; therefore, the overall nonlinearity condition of the area array can be intuitively evaluated.

The invention provides a broadband radio frequency radiation unit output linearity test system and method, relates to the technical field of radio frequency microwave measurement, and solves the limitation problems of low system debugging efficiency, difficult spectrum quality regulation and control and the like in the prior art. The system comprises a signal generation device, a spectrum analysis device, a power attenuation device, a control device and a connection device, and the control device is configured to control output parameters of the signal generation device, attenuation parameters of the power attenuation device and working parameters of the spectrum analysis device and send a control instruction to a tested broadband radio frequency radiation unit. The attenuation state of an internal power regulation unit and the conduction path of an internal signal selection unit are regulated; and the connecting device constructs a radio frequency link between a preset monitoring point in the tested broadband radio frequency radiation unit and the input end of the spectrum analysis device through the radio frequency transmission line. The method effectively improves the final output frequency spectrum quality of the system, shortens the debugging period of the system, and is beneficial to batch production and maintenance.

The invention discloses an extremely-weak light radiance calibration system and method based on cascaded integrating spheres, and belongs to the technical field of optical radiation measurement and photoelectric detection. The system comprises a first integrating sphere, a diaphragm cylinder and a second integrating sphere, the diaphragm cylinder realizes large dynamic range light intensity adjustment through geometric attenuation, the second integrating sphere is connected with a reference detector and a to-be-calibrated high-sensitivity detector at the same time, and online calibration and dynamic range bridging in the same radiance field are realized. And luminous flux distribution is controlled by adjusting the aperture of the diaphragm, so that the measurement ranges of the two detectors are overlapped, and correction processing related to the non-ideal effect of the single-photon detector and high-precision measurement of extremely-weak light radiance are executed. The device is compact in structure, stable in attenuation and reproducible, and is suitable for weak light calibration and linearity test in the fields of quantum optics, night remote sensing and the like.

The application discloses a high-precision ADC linearity test method and system, comprising the following steps: inputting a plurality of signal differences to an ADC through a control signal generator, a voltage source, an operator and a channel of a multiplexer, and obtaining a group of output code bits of each signal difference; summing and subtracting two preset signal differences, and summing and subtracting the output code bits of the two preset signal differences, to obtain summing and subtracting results; determining a multivariate linear equation group according to a preset segmented nonlinear model containing a parameter to be solved, the summing and subtracting results and the output code bits; obtaining an optimal solution by solving the equation group, and determining integral nonlinear errors and differential nonlinear errors of the ADC according to the optimal solution and the preset segmented nonlinear model. The application can calculate common-mode and differential-mode of integral nonlinearity and differential nonlinearity, can reduce the precision requirement of an input signal, can greatly shorten test time and sampling points, and has simple system structure, fast algorithm running speed and wide application prospect.

The application discloses a circuit, system and method for MEMS gyroscope conditioning circuit linearity evaluation. The circuit simultaneously provides a driving channel signal and a detection channel signal to a gyroscope conditioning circuit chip, the driving channel comprises a first single-ended to differential amplifier receiving a driving signal, a first modulation circuit receiving a timing control signal, and a first capacitor and a second capacitor for outputting the driving channel signal provided by the first capacitor and the second capacitor to simulate a sensitive structure of a MEMS gyroscope; the detection channel comprises a second single-ended to differential amplifier receiving a detection signal, a second modulation circuit receiving the timing control signal, and a third capacitor and a fourth capacitor for outputting the detection channel signal provided by the third capacitor and the fourth capacitor to simulate the sensitive structure of the MEMS gyroscope, so that the linearity test standard of the gyroscope signal conditioning circuit is unified, and the test mode is simpler.

The application relates to the fields of infrared optical film technology and precise photoelectric testing technology, and provides an attenuating piece, a preparation method, an attenuating piece wheel assembly, a testing system and a testing method. The application utilizes a first attenuating piece group and a second attenuating piece group to form an attenuating piece, each first attenuating piece in the first attenuating piece group adopts a zinc selenide base material and a nickel film and has high spectral transmittance; each second attenuating piece in the second attenuating piece group adopts a silicon base material, a gold film and a chromium adhesion layer and has high spectral transmittance; the attenuating piece is applied to an infrared detector nonlinearity testing system, different first attenuating pieces and second attenuating pieces can be combined to construct an attenuating assembly with a large dynamic range. The testing system using the attenuating piece can realize automatic scanning of incident photon flux density across more than four orders of magnitude, solves the problems of preparation and system integration of a mid-wave large dynamic range attenuating device, and improves the efficiency and reliability of infrared detector response nonlinearity testing.

The invention discloses an automatic test method of an isolation amplifier. The automatic test method comprises the following steps: step 1) building a peripheral test circuit of the isolation amplifier; the method for testing the linearity of the isolation amplifier based on the peripheral test circuit can greatly improve efficiency and data stability. The method for testing the linearity of the isolation amplifier based on the peripheral test circuit can be used for testing the linearity of the isolation amplifier based on the peripheral test circuit.