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Comment by zitterbewegung | Hacker News Reader

Could you create a communications system with these solid state receivers ? I'm thinking about a communication network with these things? Or is that impossible.

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Yes, if you have a circuit that can operate at .85Thz you can modulate it between say .84 and .845 Thz. It is fairly straight forward to build a circuit to detect the frequency of a signal by sampling 10 cycles of that signal. Further the difference between .84Thz and .845Thz is 5Ghz. That is a pretty big difference so easy to detect. 10 cycles per 'baud' would yield a baudrate of 84Gbs or with 8b/10b encoding 8.4GB/s. That's 120 DVDs per minute :-) The Shannon limit is 10x that.

It would have to be line of sight of course, its not going to reflect off much.

Well, right now, the article only mentions a receiver. So you're half-way there, you just need to build a transmitter.

An oscillator with a loose wire [1] is a transmitter :-)

[1] http://sci-toys.com/scitoys/scitoys/radio/am_transmitter.htm...

And do please show how to build an 0.85 THz oscillator...

Connect a capacitor to be base of a .85Thz transistor. My favorite design for the simplest form of relaxation oscillator [1].

[1] http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/relaxo... can't draw the one from the Art of Electronics here but this site captures it pretty well. The 'trick' is having a .85Thz transistor.

AFAIK, an oscillator is necessary for building a receiver. In other words, this is apparently a solved problem.

Well, you do get vacuum tubes that operate up to a terahertz - they don't count as solid-state devices, though.

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