Alt-BEAM Archive
Message #07297
To: beam@sgiblab.sgi.com
From: Bob Shannon bshannon@tiac.net
Date: Tue, 02 Nov 1999 19:49:12 -0500
Subject: [alt-beam] Re: directional antenna?
Radio waves move at a foot per nanosecond, TTL is not
fast enough.
But for BEAM applications, I'd reccomend using a ferrite loopstick
antenna, like is found in hand-held AM radios.
Evan Dudzik wrote:
> does anyone have any ideas on how to build a
> unidirectional antenna? this would be great for homing
> in on RF signals... otherwise, i have another idea.
> take three antennas, and place one in the center of
> the bot... take the next two and place them at the
> left and right sides of the bot. now, have a beacon
> set up that transmits signals... it just has to
> transmit a signal, wait for like a second, and then
> trasnmit another... the robot will have its central
> antenna on at all times, waiting for that first
> signal. when it recieves it, it turns on the other
> two recieving antennas... when the signal comes, it
> will reach one antenna BEFORE the other because that
> antenna is closer. The difference between times would
> be REALLY short, so the bot would have to have some
> quick detecting circuitry (TTL... isnt that really
> fast? fast enough?) this whole thing is kinda how our
> ears work, sound reaches one side before the other.
> any ideas on circuitry? or whether this thing would
> even work? it would be good to help a bot home in on
> its charging station... or other uses. anyway,
> thanks.
>
> =====
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> |Evandude Dudzik |
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