WIDEBAND RADAR ADAPTIVE BEAMFORMING USING FREQUENCY- DOMAIN DERIVATIVE BASED UPDATING
Ben Mathews, Jacob D. Griesbach, Alison Hamilton Brown · 2007
This paper details an advanced wideband adaptive beamforming algorithm for multi-channel radar systems that is currently in the process of being implemented in an FPGA. This approach models the entire frequency spectrum and linearly tracks statistical source covariance changes over frequency. achieved using a technique called derivative based updating (DBU). The novel aspect of this algorithm is its application in the frequency domain to track jammer source variations in angle as a function of frequency. This algorithm is compared with a traditional subband ECCM technique for multiple jamming scenarios. Front-end array hardware recommendations are also considered in this presentation. The baseline front-end architecture involves use of non-overlapping subarrays to reduce the number of digitized channels. An overlapping architecture is recommended that gives greater flexibility and control over spatial ambiguities. With wider operating bandwidths come increased processing demands on the beamforming hardware. By taking advantage of the increasing processing power available in commercially available Field Programmable Gate Arrays (FPGA), and with the increasing speed of modern digital interfaces, it is becoming increasingly feasible to perform wideband adaptive processing in the digital domain, where advanced beamforming techniques can be exploited to realize performance and flexibility benefits of a portable firmware-based implementation.