Abstract. Research results are presented on substantiating the structure of transmitting and receiving channels for a multichannel two-coordinate primary coherent radar with multiple identical N-inputs and M-outputs of the MTx-NRx type. The radar utilizes continuous periodic linear frequency-modulated probing signals to detect and measure the polar coordinates of low-observable [low-RCS] targets in the short-range surrounding air and ground space. The advantages and design features of multichannel Multiple Input Multiple Output (MIMO) radars are noted, including modular design, low radiated power, low probability of intercept [LPI] operation, and the use of orthogonal probing signals emitted by the transmitting channels and reflected radar signals received by the receiving channels, as well as mobility, low weight, and compact dimensions. It is shown that the carrier frequency of an azimuthal multichannel two-coordinate coherent radar is determined by the partial beamwidth of a virtual fan-shaped transmit-receive radiation pattern in azimuth and the size of the azimuthal virtual aperture, considering its excess over a given maximum physical horizontal antenna aperture. It is noted that the number of transmitting (M) and receiving (N) channels of an azimuthal multichannel MIMO-type two-coordinate radar is determined by the required number of high-frequency transmitting radiators and receiving antenna elements. This configuration must ensure the formation of a virtual M×N-beam transmit-receive fan radiation pattern covering the operational zone in azimuth and elevation with a specified azimuthal resolution. A configuration for the mutual arrangement of M = 8 transmitting radiators and N = 8 receiving high-frequency antenna elements within the physical aperture of a multichannel transmit-receive antenna array, limited to a width of 1 m, is proposed. This variant provides the formation of an extended virtual aperture with a fan-shaped azimuthal transmit-receive radiation pattern in the radar coverage area, defined by a spatial sector of 60° in azimuth and 20° in elevation. It is shown that the proposed 8Tx-8Rx multichannel two-coordinate radar, emitting orthogonal probing signals at a carrier frequency of 15 GHz in the Ku-band via a 1-meter-wide planar antenna array with 10 mW of power per each of the 8 transmitting channels, ensures the detection and measurement of the polar coordinates of low-observable targets. For unmanned aerial vehicles with radar cross-sections of 0.01 m² and 0.1 m², detection is achieved at maximum ranges of 2.9 and 4.4 km, respectively (with an observation time of 1 s), and 5.1 and 7.6 km (with an observation time of 5 s).

Keywords: virtual aperture, radiation pattern, primary radar, resolution, radar, MIMO

Для цитирования: Sinitsyn V. A., Ivanov A. V., Sinitsyn E. A. Multichannel radar for short-range low-observable target detection. Aerospace Engineering and Technology. 2026. Vol. 4, no. 2, pp. 357–371. (In Russ.) https://doi.org/10.52467/2949-401X-2026-4-2-357-371; https://elibrary.ru/nuosiv  

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