4results about How to "Improve output linearity" patented technology

The application provides a new hybrid nested noise shaping architecture suitable for noise shaping SAR ADC, which adopts a dynamic working closed-loop cascode FIA as a residual amplifier to reduce power consumption by eliminating the static current of the amplifier and removing the gain calibration circuit; the shaping architecture performs fourth-order noise shaping through the nested second-order CIFF and second-order EF noise shaping loops to achieve high precision in noise shaping at the same oversampling rate, and integrates the sampling noise cancellation (SNC) method to reduce the capacitance of the sampling capacitor to save chip area; the architecture adopts a closed-loop cascode FIA as a residual amplifier and CIFF and EF as noise shaping loops to solve the problem that the traditional noise shaping SAR ADC is difficult to simultaneously achieve high precision and low power consumption. In addition, the sampling KT / C noise cancellation (SNC) technology is integrated to reduce the capacitance of the sampling capacitor and save chip area.

The application discloses an R-2R digital-analog converter with an auxiliary calibration structure and relates to the technical field of high-precision digital-analog conversion. The converter comprises a main DAC, a calibration quantity calculation module, a compensation code generation module, an auxiliary DAC and an operational amplifier circuit. The main DAC converts a digital input into an analog current. The calibration quantity calculation module generates a 15-bit compensation code containing a 1-bit sign bit and a 14-bit data bit through a 24-bit ADC, a comparator and successive approximation logic, and only calibrates the high 12 bits of the main DAC bit by bit, and the low 4 bits do not need to be calibrated. The compensation code generation module generates a total compensation code through gating by a multiplexer and superposition by an adder. The auxiliary DAC is a 14-bit binary current type structure, and realizes bidirectional compensation in cooperation with a positive and negative reference voltage source. The application has the advantages of short calibration period, small storage consumption, no need for additional bias calibration, excellent linearity, and suitability for application in the fields of wireless communication, biological medicine and the like, and meets the application requirements of high resolution and high precision.

The invention relates to the technical field of magnetic variable measurement, and discloses a closed-loop fluxgate current detection system, which is characterized in that a self-excited oscillation unit is connected with a PAC conversion unit, the PAC conversion unit is connected with an integration unit, the duty ratio of a square wave signal is converted into a voltage deviation signal, and the voltage deviation signal is provided for the integration unit; the integration unit is connected with the feedback compensation unit and is used for integrating the voltage deviation signal and providing an integration voltage; the self-excited oscillation unit adopts a symmetrical driving structure comprising an analog switch, and provides a square wave signal representing a duty ratio for the PAC conversion unit; and the feedback compensation unit is connected with the compensation winding, outputs a voltage signal in proportion to the current to be detected and drives the compensation winding to generate a counteracting magnetic field so as to form closed-loop detection. The problems of low bandwidth, zero drift, structure limitation and high cost in the prior art are solved, and the purposes of high bandwidth, openable installation, low ripple output, high precision and extremely high symmetry and consistency are achieved.

The invention belongs to the technical field of data processing of the computer information disciplinary, and relates to a broadband power amplifier linearization method and system based on predistortion, and the method comprises the steps: collecting and preprocessing a radio frequency input baseband signal, an actual output baseband signal and tube core heat flow data of a broadband power amplifier, and obtaining an initial data set; calculating a transient heat dissipation gradient at each sampling moment based on the signal energy difference and the tube core temperature change rate; in combination with broadband distribution characteristics of radio frequency input baseband signals, broadband thermal teratogenesis factors at all sampling moments are obtained; performing dynamic tracking compensation on a cross term coefficient of a generalized memory polynomial based on the distortion factor to obtain an update coefficient; and the pre-distortion signal is reconstructed by utilizing the updating coefficient, so that high-linearity output of the broadband power amplifier is realized. The dynamic response speed of coefficient updating can be improved, thermally induced nonlinear distortion of a power amplifier is effectively offset, and the linearity and stability of a high-power broadband radio frequency test are improved.