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: http://www.arcetri.astro.it/science/Radio/instr/uniboard/
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It has been developed basically as a building block for future VLBI correlators, but can be used for a number of other applications, including adaptive beamforming, pulsar dedispersion, RFI identification and suppression.
Uniboard top side (click to enlarge)
Here at Arcetri we are studying its use as a wideband digital receiver. The receiver characteristics are:
Simulation of the polyphase FFT filterbank. Input signal is a sinewave sweeping the entire 4 GHz band. Outputs are given for channels 0, 1, 15, 8, 16, 17, 30, 24, 31 (top panel) and 2, 3, 13, 14, 17, 18, 28, 29 (bottom panel)
A separate version with 1 GHz bandwidth has also been developed. This version fits nicely in a single FPGA, so 4 independent bands can be analyzed in 4 FPGAS leaving the other 4 for other purposes (spectropolarimetry, pulsar dedispersion, RFI mitigation).
1 GHz bandwidth splitted into 16 64 MHz subchannels. Top 9 graphic tracks are the 9 outputs from the polyphase FFT. Bottom 16 tracks are the outputs of individual sub-channels (0 to 15). Channel 10 has been programmed for a 32 MHz bandwidth.