Real‐time beamforming using high‐speed FPGAs at the Allen Telescope Array

[1] The Allen Telescope Array (ATA) at the Hat Creek Radio Observatory (HCRO) is a wide-field panchromatic radio telescope currently consisting of 42 offset-Gregorian antennas each with a 6 m aperture, with plans to expand the array to 350 antennas. Through unique back-end hardware, the ATA performs real-time wideband beamforming with independent subarray capabilities and customizable beam shaping. The beamformers enable science observations requiring the full gain of the array, time domain (nonintegrated) output, and interference excision or orthogonal beamsets. In this paper we report on the design of this beamformer, including architecture and experimental results. Furthermore, we address some practical considerations in large-N wideband beamformers implemented on field programmable gate array platforms, including device utilization, methods of calibration and control, and interchip synchronization.

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