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> What would be really cool is to build a USB board that plugs into one of the SB9210 boards and connects to gnuradio. You could do all kinds of neat radar expe

> What would be really cool is to build a USB board that plugs into one of the SB9210 boards and connects to gnuradio. You could do all kinds of neat radar experiments, presence detection, beam forming, you name it. Kind of like a 60 GHz RTL-SDR. Maybe a dumb question, but how is it even possible to do SDR with 60GHz signal on a ~4GHz CPU via a 5Gbps USB3 connection? EDIT: I guess via down-conversion? https://en.wikipedia.org/wiki/Digital_down_converter https://en.wikipedia.org/wiki/Digital_down_converter

derefr 7y ago
Or just buffer each broadcast segment into some 60GHz memory (is there such a thing?), and either rely on your signalling protocol being TDMI (and you therefore not needing to send/receive more than a fraction of the time) or on your broadcast signal being periodically repeating, such that the radio can just treat that memory as a ring buffer to play over and over. Or, do what old computer architectures did when their CPUs were slower than their DACs: add a Programmable Interval Timer (i.e. a very simple synthesizer) in between, such that you just send a few commands and it adds together some 60GHz triangle and square waves to achieve the signal shape you want. Maybe even add a sequencer, and then stream it some 60GHz MIDI files!
blueintegral 7y ago
The data itself isn't 60 GHz, you're just modulating it onto a 60 GHz carrier. https://en.wikipedia.org/wiki/Modulation https://en.wikipedia.org/wiki/Modulation
numpad0 7y ago
Modulated carriers are rarely directly synthesized by logic circuitries, even with phased arrays. You tap off a “white light source” of correct wavelength just like you do with LCD. TX/RX rates are thus independent to the carrier frequency. Only local oscillator must to be able to be configured to the correct carrier frequency.
bschwindHN 7y ago
For a concrete example, infrared (such as what's used for TV remotes) typically transmits data on a carrier frequency of 38Khz, but the actual data rate is much less, just a few hundred bits per second. https://techdocs.altium.com/display/FPGA/NEC+Infrared+Transmission+Protocol https://techdocs.altium.com/display/FPGA/NEC+Infrared+Transm...

derefr 7y ago

Or just buffer each broadcast segment into some 60GHz memory (is there such a thing?), and either rely on your signalling protocol being TDMI (and you therefore not needing to send/receive more than a fraction of the time) or on your broadcast signal being periodically repeating, such that the radio can just treat that memory as a ring buffer to play over and over. Or, do what old computer architectures did when their CPUs were slower than their DACs: add a Programmable Interval Timer (i.e. a very simple synthesizer) in between, such that you just send a few commands and it adds together some 60GHz triangle and square waves to achieve the signal shape you want. Maybe even add a sequencer, and then stream it some 60GHz MIDI files!

blueintegral 7y ago

The data itself isn't 60 GHz, you're just modulating it onto a 60 GHz carrier. https://en.wikipedia.org/wiki/Modulation https://en.wikipedia.org/wiki/Modulation

numpad0 7y ago

Modulated carriers are rarely directly synthesized by logic circuitries, even with phased arrays. You tap off a “white light source” of correct wavelength just like you do with LCD. TX/RX rates are thus independent to the carrier frequency. Only local oscillator must to be able to be configured to the correct carrier frequency.

bschwindHN 7y ago

For a concrete example, infrared (such as what's used for TV remotes) typically transmits data on a carrier frequency of 38Khz, but the actual data rate is much less, just a few hundred bits per second. https://techdocs.altium.com/display/FPGA/NEC+Infrared+Transmission+Protocol https://techdocs.altium.com/display/FPGA/NEC+Infrared+Transm...