Cascade digital filter anti-communication jamming method based on P band radio frequency sampling

Abstract

The invention relates to the field of radar against active jamming and particularly relates to a cascade digital filter anti-communication jamming method based on P band radio frequency sampling. Direct bandpass sampling digitalization is carried out on radio frequency echo signals received by the radar through an ADC chip, the sampled digital signals are subjected to digital down conversion, after digital mixing and multilevel decimation filter, needed baseband signals are obtained, and besides, spectrum aliasing is not introduced, high performance digital filter out-of-band rejection abilityis achieved, communication jamming outside an operating frequency point can be filtered out, and requirements of target detection display are met. Same frequency band communication jamming by radar sidelobe entering can be effectively restrained, the radar against jamming ability is enhanced, and a detected and extracted picture is improved.

Description

technical field [0001] The invention relates to the field of radar anti-active interference, in particular to a cascaded digital filter anti-communication interference method based on P-band radio frequency sampling. Background technique [0002] Countering mobile communication interference in the same frequency band is a realistic requirement for radar in complex electromagnetic environments. At present, radar systems usually use superheterodyne intermediate frequency sampling digital receivers, which have low requirements for digital circuits and are easy to implement. However, in this mode, analog frequency mixing and filtering are required for the signal. The analog RF front-end is relatively complex and has limited flexibility, which is prone to problems such as analog circuit aging and parameter drift. Limited to its own performance, under normal circumstances, the suppression ability outside the operating frequency point ±10MHz is not less than 50dB. Considering the ...

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Problems solved by technology

However, in this mode, analog frequency mixing and filtering are required for the signal. The analog RF front-end is relatively complex and has limited flexibility, which is prone to problems such as analog circuit aging and parameter drift. Limited to its own performance, under normal circumstances, the suppression ability outside the operating frequency point ±10MHz is not less than 50dB. Considering the actual situation such as communication interference intensity, radar antenna sidelobe gain, receiver gain, receiver sensitivity, etc., it is difficult to effectively suppress radar side Lobe-entry co-band communication interference

[0003] The working frequency band of the P-band radar overlaps with the mobile communication frequency band, so that the target echo of the radar is easily interfered. When the analog filter is used, due to its insufficient suppression ability, the overall performance of the radar will be greatly affected.

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