Quantitative testing for sensitivity of a non-coherent FMCW autodyne receiver

Abstract

The invention discloses a method for testing sensitivity of a non-coherent FMCW autodyne receiver. Firstly, a power stepping value covering initial power of a minimum signal which can be received by a receiver in practical working and satisfies a precision requirement in practical working is set in a standard signal-generator; the signal-generator is arranged to be of an internal pulse modulation mode so as to generate test signals of the non-coherent FMCW autodyne receiver; test signals generated by the signal-generator are feed into the non-coherent FMCW autodyne receiver via a test antenna, and are subjected to detection in a detector in the non-coherent FMCW autodyne receiver; a direct current demodulation voltage signal Vd is output in real time to be displayed on an oscilloscope; the Vd is read out on the oscilloscope to be compared with a preset threshold magnitude of voltage VG; if the Vd=VG, a test person records the present signal source output power Prf; and the sensitivity of the non-coherent FMCW autodyne receiver is calculated according to the Prf. According to the invention, problems that the sensitivity of the autodyne receiver can not be accurately tested due to frequency temperature drift of frequency temperatures of a built-in VCO of the non-coherent FMCW autodyne receiver are solved.

Description

technical field [0001] The invention relates to a quantitative testing method mainly related to the sensitivity of non-coherent frequency modulation continuous wave (FMCW) radar self-differential receiver. Background technique [0002] After decades of development, continuous wave radar (CW) has become relatively mature and has been widely used in many projects. Compared with pulse radar, continuous wave radar requires low transmission power, high detection accuracy, and relatively simple structure. It is easy to implement solid-state design, and has good low probability of intercept (LPI) performance, etc. However, pure continuous wave radar can measure the speed information of the target, but cannot measure the distance information of the target. To solve this problem, frequency modulated continuous wave (FMCW, Frequency Modulated Continuous Wave) radar has been extensively researched and widely used in systems such as distance measurement, speed measurement and vehicle c...

AI Technical Summary

Problems solved by technology

The non-coherent FMCW radar self-differential receiver directly uses the coupled transmission signal as the local oscillator. Since the VCO is integrated in the system, it has relatively independent frequency sweep characteristics. At the same time, because the VCO has a large frequency drift, the sensitivity of the test receiver When the RF signal fed from the RF port is mixed with the local oscillator signal generated by the VCO, the frequency of the intermediate frequency signal is unstable, and then the voltage of the intermediate frequency detection is unstable, especially in the millimeter wave frequency band, and the temperature drift of the VCO is much larger than that of the intermediate frequency filter. width, the detection voltage fluctuates violently, and it is difficult to accurately test the sensitivity of the receiver

By frequency-locking or phase-locking the VCO, or realizing the coherent and synchronous drift between the test input signal and the VCO through an external instrument, the problem of unstable detection output power caused by the temperature drift characteristics of the VCO can be solved, but it will significantly increase the frequency of the FMCW radar system. Circuit complexity, increase system volume, power consumption and cost, or increase test system complexity, sacrifice test system flexibility and versatility, increase test cost

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