Angle Of The Antenna Near-field Calibration And Distance No Tower Zero,

Angular calibration of radar antenna system is composed of the calibration of angular error sensitivities (also called directional sensitivity), adjustment of cross-coupling of azimuth and elevation signals, and the calibrations of system errors such as antenna axial system error, dynamic delay and so on. This paper mainly studies the coupling error caused by induction voltage phase difference, and fluctuation of directional sensitivity caused by changes in near-field difference slope. The trend of system sum and difference phase difference, directional sensitivity and cross-coupling with change in distance is compared and discussed when the antenna is in the near-field and at a certain elevation. It has put forth the minimum calibration range and error correction provided it is accepted by engineering requirements.Zero-range calibration is determination of the zero range value of equipment with a "reverse-measurement method". Based on engineering experience of the author and theoretical experience, the physical and geometry delay from feed center to off-set element under near-field environment is compared and discussed, and the influence of near-field conditions on zero-range calibration is analyzed, and satisfactory results have been got.