Low-scattering radar medium frequency echo signal analog source

Abstract

The invention discloses a low-scattering radar medium frequency echo signal analog source. The analog source comprises a micro-control unit, a medium frequency signal generating and conditioning unit, a medium frequency mixing unit and a power supply unit, wherein the medium frequency signal generating and conditioning unit and the medium frequency mixing unit are sequentially connected with the micro-control unit; the power supply unit is used for supplying power to the units. The medium frequency signal generating and conditioning unit comprises a first frequency synthesis unit and a second frequency synthesis unit for respectively generating medium frequency linear frequency modulation signals, simple-frequency signals with continuous phases. The two paths of generated signals are subjected to up-conversion mixing, band-pass filtering treatment and down-conversion mixing and band-pass filtering treatment to finally obtain the needed low-stray linear frequency modulation echo signals. By adopting the analog source, under the condition of guaranteeing the excellent spectral characteristics of the signals, the frequency difference between the two paths of signals is increased; the condition of acquiring the signals with excellent spectral characteristics can be created for secondary mixing; the two paths of signals are subjected to down-conversion mixing and filtering, the low-stray linear frequency modulation echo signals can be finally obtained; the continuity of the signals on the phase can be guaranteed.

Description

technical field [0001] The invention relates to the field of radar signal simulation in the simulation test of a radar seeker, in particular to a low-scattering radar medium-frequency echo signal simulation source. Background technique [0002] The chirp signal obtains a certain bandwidth signal through the continuous linear change of the signal frequency during the pulse duration. As a commonly used radar signal, it is used in the radar seeker because of its good pulse compression characteristics and resolution ability. widely used. However, a low spurious chirp radar echo signal simulation source with good spectrum characteristics is particularly important in the development and simulation testing of the seeker. [0003] The chirp radar echo signal mainly includes two parts of the signal, one is the chirp signal emitted when the radar itself is working, and the other is the Doppler signal generated by the relative motion of the projectile and the target. The common metho...

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Problems solved by technology

At the same time, in the middle frequency band, when the working frequency bands of the two signals to be mixed are very close, if direct mixing is performed, the mixed signal will have relatively high power low-order harmonic interference in the working frequency band, and This interference is difficult to completely filter out by a bandpass filter, thus reducing the effective operating bandwidth of the signal source

[0004] At present, there are similar patents and technologies at home and abroad, such as the patent "Low spurious small-step high-speed FM frequency synthesizer", publication number CN102013889A; "Fine step ultra-wideband frequency conversion low spurious low phase noise frequency synthesizer" , publication number CN102571086A, but the output signals of these two frequency synthesizers do not contain Doppler information, and cannot be used to simulate the velocity information of target echoes in actual radar tests

[0005] In the paper "Design of an IF Radar Simulator" in the "Journal of the Academy of Naval Aeronautical Engineering" in 2012, Volume 27, No. 3, a design of a linear FM radar IF signal source is introduced, but the simulated Doppler signal It is difficult to guarantee the continuity of the phase, so it will not be able to meet the requirements in the radar test of some coherent systems

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