"JOURNAL OF RADIO ELECTRONICS" (Zhurnal Radioelektroniki ISSN 1684-1719, N 6, 2018

contents of issue      DOI  10.30898/1684-1719.2018.6.8     full text in Russian (pdf)  

Analysis of the power spectrum of phase noise of the signal at the output of a radar receiver with a continuous frequency-modulated signal


L. B. Ryazantsev, I. F. Kupryashkin, V. P. Likhachev

Air Force Military Educational and Scientific Center “Air Force Academy named after Professor N.E. Zhukovsky and Y.A. Gagarin”, St. Bolshevikov 54a, Voronezh 394064, Russia


The paper is received on May 28, 2018


Abstract. Today the radar stations with continuous wave broadband linear frequency modulated waveforms are used in advanced driver assistance systems, ground radar systems for drone detection, airborne systems of imagery intelligence and some other fields of activities, thanks to their compact sizes, low power requirements and relatively low costs. The research performed in the article shows that the effect of transmitter phase noise suppression in the receiver output channel is present in LFM-CW radars, and its significance depends on the distance to the target. The largest values of suppression are reached for the signal phase noises of the targets situated close to the radar. The expressions for calculation of the power spectrum density of the phase noises in the output of an FMCW radar receiver and the technique of their suppression level calculation for the specified characteristics of the frequency synthesizer in use and radar operation range are given in the article.

The derived ratios and dependencies allow estimating the acceptable level of frequency synthesizer phase noise and substantiate its choice accounting for the effect described above and for the LFM-CW radar observation region characteristics. The fact that the consequence of the suppression effect is the reduction of the target's demodulated echo signal phase noise level by 10...30 dB and more depending on its distance from the radar allows to draw a conclusion that relatively simple and low-cost frequency synthesizers can be utilized in LFM-CW radars, thus allowing to simplify its construction, reduce its weight, sizes and cost. Besides that, the derived results can be used in the research of frequency modulated noises effect on auto-correlational receivers, which are used, for example, as the LFM-CW radio signals parameters estimation devices in radio-technical intelligence systems.

Key words: continuous wave, phase noise, power spectrum density.


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For citation:

L. B. Ryazantsev, I. F. Kupryashkin, V. P. Likhachev. Analysis of the power spectrum of phase noise of the signal at the output of a radar receiver with a continuous frequency-modulated signal. Zhurnal Radioelektroniki - Journal of Radio Electronics. 2018. No. 6.  Available at http://jre.cplire.ru/jre/jun18/8/text.pdf

DOI  10.30898/1684-1719.2018.6.8