METHOD FOR DIGITAL FORMATION OF BEAM PATTERN OF ACTIVE PHASED ANTENNA ARRAY DURING RADIATION AND RECEPTION OF LINEAR-FREQUENCY-MODULATED SIGNALS

摘要

FIELD: physics.;SUBSTANCE: use: in radar stations with active phased antenna arrays (APAA) with digital formation of directional patterns (DP) both for transmission, and to reception when used as probing pulse broadband linear-frequency-modulated (LFM) signals and in wide-angle electronic scanning of the directivity pattern. Essence of the invention lies in the fact that the digital LFM signal is digitally generated, the digital LFM signal is distributed over the APAA receiving/transmitting modules (RTM), in each m^th RTM (m = , where M is the number of the RTM), the signal is multiplied by a complex coefficient , where is the required phase shift for each m^th RTM when generating a DP in the direction relative to the normal to the antenna aperture, in each m^th RTM signal is additionally multiplied by the complex coefficient , correcting distortion of phase distribution of field on antenna aperture caused by deviation of frequency of LFM signal and electronic scanning of the DP, converting the received signal into an analogue form, amplifying and emitting each m^th RTM, thereby forming a DP for transmission in accordance with a defined ratio, in the APAA operation mode, received by each m^th RTM receiving signal is amplified, digitized, a wide spectrum of the received signal of narrow-band sections I = is separated, where width of the narrow-band spectral region satisfies the criterion c/L_a, c is the speed of light, L_a is the linear size of the antenna aperture in the APAA DP scanning plane, extracting the complex envelope of each i narrow-band signal of each m^th RTM , where is the amplitude, and is the phase advance of the i^th narrow-band signal at the input of the m^th RTM, is the direction of incidence of the electromagnetic wave on the aperture of the APAA relative to the normal to it, multiplying the complex envelope of the i^th signal by complex coefficient , where is the required phase shift for each i^th narrow-band signal of the m^th RTM when receiving the signal from the direction relative to the normal to the APAA aperture, complex envelope of the received signal at the output of each m^th RTM is formed by summation of obtained products.;EFFECT: technical result is enabling digital formation of the APAA beam pattern in conditions of wide-angle electronic scanning of the beam pattern when receiving LFM signals when the time of arrival of the signal reflected from the target at the input of the receiver is unknown.;1 cl, 2 dwg