COMPENSATED MULTIELEMENT RECEIVING ANTENNA FOR DEEP-BATHYMETRIC SIDE-SCAN PHASED SONAR Russian patent published in 2003 - IPC

FIELD: underwater technology; devices for shaping submarine bottom topography pattern. SUBSTANCE: antenna designed for sonars which are used to shape three-dimensional pattern of submarine bottom topography for its surveying using audio or ultrasonic waves and incorporating means for suppressing unwanted oscillations has case accommodating several rows of rectangular piezoids. Each row of piezoids consitiues separate linear antenna whose width is below λ/2 and length equals that of receiving antenna. Linear antennas are disposed widthwise of receiving antenna at distance shorter than λ. Receiving antenna has rear screen placed in parallel to its front surface and formed by layers of acoustically soft and acoustically hard materials. Gaps between linear antennas and those between receiving-antenna case and extreme linear antennas are filled with screening layer of acoustically soft material. Each gap is divided through its width into two parts by means of rib made of acoustically hard material; width of these parts of gap and that of rib are equal and they are shorter than operating frequency wavelength λ. Rib height is chosen to satisfy condition h_m≈λ_m/2•m and height of screening layer, to satisfy condition h_p≈λ_p/4•n where λ, λ_m, λ_p is wavelength in working medium, in acoustically hard, and acoustically soft materials, respectively; n = 1, 3 , m = 1, 2 . Rubber is used as acoustically soft material for rear screen and for screening layer. Acoustically hard material for rear screen and for ribs is metal. Angular resolution of receiving antenna is enhanced due to generating identical amplitude and linear phase characteristics by reducing interaction between separate linear antennas with respect to field and internal volume of receiving antenna. EFFECT: enhanced angular resolution of antenna. 4 cl, 3 dwg