Abstract:
RF antenna array beamforming based on electronically
steerable wideband phased-array apertures find applications
in communications, radar, imaging and microwave sensing.
High-bandwidth requirements for wideband RF applications
necessitate hundreds of MHz or GHz frame-rates for the digital
array processor. A systolic architecture is proposed for the realtime
implementation of the 2-D IIR beam filter. This implementation
employs a differential-form polyphase 2-D IIR frequencyplanar
beam filter, and a corresponding circuit architecture in
order to achieve the real-time computation of the input-output
2-D difference equation that defines the RF beam filter. The
feasibility of real-time implementation for dense aperture arrays
operating in the 0-240 MHz band using a beam filter is explored.
The proposed 2-phase sampling scheme per antenna is based on
a 2-D IIR polyphase structure. A digital hardware prototype is
designed, implemented and tested using a ROACH-2 fitted with
a Xilinx Virtex-6 Sx475t FPGA chip and a 32-channel timeinterleaved
RF data converter, which support 16 antennas using
2-phase time-interleaved sampling at an FPGA clock rate of 240
MHz.
Citation:
V. Seneviratne, A. Madanayake and L. T. Bruton, "A 480MHz ROACH-2 FPGA realization of 2-phase 2-D IIR beam filters for digital RF apertures," 2016 Moratuwa Engineering Research Conference (MERCon), 2016, pp. 120-125, doi: 10.1109/MERCon.2016.7480126.