VCO open-loop linearity correction method

Abstract

The invention provides a VCO open-loop linearity correction method comprising the following steps of: (a), sampling the VCO control voltage, measuring the VCO output frequency corresponding to the sampled control voltage, and storing the data in an array M; (b), averaging and interpolating the array M; (c), according to an operation result obtained by the averaging and interpolating, fitting a corresponding line by locking two points in the operation result to form a new array N; (d), storing the data in the array N and outputting a corrected modulation voltage value through a DAC. The methodimproves the resolution of the output voltage, enables the VCO output frequency and the voltage to remain substantially linear throughout a scanning process, and guarantees the accuracy of FMCW radarmeasurement.

Description

technical field [0001] The invention relates to the radar field, in particular to a VCO open-loop linear correction method. Background technique [0002] For FMCW radar, the nonlinearity of VCO (Voltage Controlled Oscillator) is one of the main problems affecting its performance. The nonlinearity of VCO has a direct impact on the resolution of FMCW radar. Due to the inherent nonlinearity of the varactor diode in the VCO, the original linear voltage-frequency curve is nonlinear, and this nonlinearity directly leads to the measurement error of the FMCW system. [0003] There are three commonly used VCO linear correction schemes: open-loop linear correction, closed-loop linear correction, and reactance compensation correction. [0004] The closed-loop linear correction method linearly corrects the characteristics of VCO electric regulation through negative feedback, which can automatically track and compensate the changes of VCO electric regulation characteristics caused by fa...

AI Technical Summary

Problems solved by technology

[0010] (1) Since the characteristic curve of the VCO electric regulation cannot be accurately expressed by an analytical formula, there are large errors in the design of the open-loop linearity correction circuit;

[0011] (2) The floor noise of the linearity corrector circuit itself will increase the output noise;

[0012] (3) There is a certain limit on the speed of the ESC;

[0013] (4) The correction circuit has poor versatility

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