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Registered Member #1792
Joined: Fri Oct 31 2008, 08:12PM
Location: University of California
Posts: 527
As with the other commenters I would recommend caution, because high power radiation is dangerous and it can be difficult to predict exactly what a particular antenna will do, or what impact your seemingly innocuous design choice has, until you have a fair amount of knowledge, skill, and experience. That doesn't mean you shouldn't do it, it just means you're undertaking a big project. Here are some references that should get you started:
*A nice antenna reference, you'll want to look at horn antennas in particular: .
*A free electromagnetism book. I'd recommend at least learning up to how plane waves work and what happens at various planar dielectric and conductor interfaces, because any of these can reflect power back at you. Which is bad at ~1kw.
I don't know what background in electromagnetism you have, but I can recommend all sorts of references if you want to know more.
You ask at what angle the waves are coming out of the magnetron. I'm not really sure as it has been a long time since I've taken apart a microwave. The wikipedia article shows a probe antenna taking energy from the magnetron cavity, so that would form a dipole antenna outside the magnetron. But you're not going to use that directly, you're going to use that probe to excite a mode in the waveguide that you made which then leads to a horn antenna. Or they might couple that probe straight into a waveguide, I don't really know.
Registered Member #2372
Joined:
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Posts: 62
I assume you would like to make a "beam" of microwaves the same way you make a beam from a laser. To get a beam to be like a laser you need its diameter to be many times the wavelength. Since the wavelength of microwaves is 12 cm you need a beam that is like over 1 meter in diameter in order to get a beam that would propagate without diverging too much. This is why no one does quasioptical until you get down to mm waves. Also the person who made those videos is stupid. When working with microwaves you should always be far away from anything important or have the experiment in an anechoic chamber so that you arent radiating everything. The exposure limit for RF is 5 mW/cm^2.
Registered Member #902
Joined: Sun Jul 15 2007, 08:17PM
Location: Pacific Northwest USA
Posts: 1042
what you might try to do is perform the experements in a microwave over - for example, ball plasma is very easily made in a conventional microwave (and they can be obtained for VERY cheap or commonly free on craigslist or similar)
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herf waveguide
