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Comment by mikewarot

2 years ago

It is amazing that we can do A/D and D/A at anything faster than audio... let alone 28 GHz D/A and 20 GHz A/D. The hardware required to anything more just process the samples at those speeds and do anything more than frequency shifting is one of the compute intense things I can imagine.

It's very rare to actually utilize the full bandwidth of the ADC to do any processing in these. The data gets immediately decimated down.

  • That's not really true, there's plenty of applications that use these sort of bandwidths. A big one is optical communications (28 GHz bandwidth is actually not super high there), but also some specialised microwave comms and radar/military. They alm do processing at 10s to 100s of GS/s (obviously highly parallel).

    • While full bandwidth applications certainly exist, it is rare. Most direct sampling schemes are used for having a purely digital RF front end within the Nyquist range of the ADC/DACs. It's cheaper and easier to develop firmware/gateware than debug analog RF issues and respin hardware.

    • That's not even crazy considering you can do tens of Teraflops/s on modern GPUs.

      Get your data into the system via PCI-E, do some RDMA magic to get the data onto your GPU and put the cores to work.