FPGA-prototypes of differential-form 2D-IIR systolic-array DSP architectures for multi-beam plane-wave filters

A low-complexity systolic-array architecture is proposed for obtaining multiple(N) broadband radio-frequency (RF) beams in smart antenna arrays. The N-beam 2D IIR digital filter is based on the concept of 2D passive ladder network resonance, leading to differential-form implementations which are highly-suitable for RF throughput levels. The proposed beamformers are converted to differential-form discrete signal flow graphs, mapped to parallel processing core modules(PPCMs) in a locally interconnected array. A 2-beam example of a 2D IIR frequency-planar beam spacetime plane-wave filter is described. A prototype design of the architecture is physically implemented on Xilinx Virtex-4 S×35-10ff668 FPGA device and verified on-chip using measured 2D impulse response and 2D magnitude frequency response tests using on-FPGA chip hardware in the loop co-simulation. The 2-beam FPGA-based example operates at a clock frequency of 40 MHz, implying a real-time frame-rate of 40 Million frames per second. FPGA prototypes are the first step towards eventualy custom silicon VLSI realizations operating at the full RF clock frequency of 800-3000 MHz.