Research Of Adaptive Sidelobe Canceling Technology In Phased Array Antenna

The main lobe beam width of a phased array radar is very narrow. The active jamming is easily to enter the sidelobe of antenna. Adaptive sidelobe canceling is an effective measure against active jamming, which forms beam pattern nulls in the direction of jamming by space filtering and assisted receiving channels. The basic principle of adaptive sidelobe canceling is introduced in this paper, and some issues needed to be paid attention to in practical engineering are pointed out. Especially , the differences in amplitude and phase between channels have large influence on adaptive sidelobe cancellation in phased array radars. This paper presents a channel equalization technology used to improve the sidelobe cancellation performance by correcting the difference. It is a kind of non-causal sample matrix inversion algorithm, in which the non-causal characteristic of the weight vector is implemented by delaying the main and the auxiliary channel signal.Rely on the fast development of the existing device level, particularly the field programmable gate array (FPGA) and digital signal processor (DSP), the design of hardware platform of adaptive sidelobe canceling system achieves a higher level. The adaptive sidelobe canceling system is designed based on standard CPCI structure, the technique of LVDS in high-speed data deliver of application. According to the structure characteristics of the arithmetic, sidelobe canceling and adaptive calculation are implemented by hardware modules with FPGA and DSP respectively.With the adaptive sidelobe canceling system already applied in phased array radars, the results verify the correctness and effectiveness of this system.