FFT-based Beamformer ASIC

NASA’s next-generation spectrometers and radiometers will utilize phased-array receivers, replacing traditional scanned-antenna RF frontends. This transition will significantly reduce size, weight, power, and cost (SWaP-C) for these instruments. Pacific Microchip Corp. (PMCC) proposes developing an 8-channel FFT-based beamformer ASIC with 32 frequency channels across a 1 GHz bandwidth, supporting 128 angular directions. The ASIC will accommodate a phased array of up to 8 antenna receivers, digitizing down-converted signals with 8-bit precision at 2GS/s. These digitized signals will be converted to the frequency domain utilizing polyphase filter banks (PFBs), followed by a second-stage FFT blocks to perform beamforming. Compared to the time-domain, the frequency-domain beamforming offers significantly greater efficiency, and the ability to observe all frequencies from all directions instantaneously. The project’s Phase I will define the project in detail and demonstrate its feasibility through extensive simulations of the proposed beamformer features and transistor-level solutions. The project’s Phase II will produce an ASIC prototype, and an evaluation PCB which can be used for developing phased-array radiometer and spectrometer instruments.