Part Of The Adaptive Array Beamforming Technology

The technology of adaptive digital beamforming (ADBF) can dramatically increase array antenna performances. Using ADBF in array antenna , some merits will be gained such as fast adaptive pattern nulling, ultra-low sidelobe, closely spaced multiple beams, high resolution direction finding (DF) and increased capacity for band-limited communications systems. The application of ADBF is limited by the high cost of digital receiver/transmitter elements. Over the recent years, as the technology of electronic components, microwave ICs and high speed digital processor continue to improve, ADBF 's practical value for phased array radar is increasing rapidly. Our research work comes from a project of line array antenna's ADBF system. In this paper two subjects are discussed: subarray partition of the line array and ADBF algorithms.The ADBF algorithm is diagonal loading QRD-SMI algorithm, which control both amplitude and phase of each array element.This paper focuses on the relation between the ratio of interfere power to noise power and the array antenna beam pattern. From that discussion, we can provide a solution for DSP implementation in which the diagonal loading value in QR_SMI algorithm can be decided automatically.This paper also discusses the ADBF hardware simulation system design and describes particularly an interface card for the system developed by the author.