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John Larkin

On Mon, 20 Aug 2007 20:25:03 GMT, wrote:

In sci.physics John Larkin wrote:
On Mon, 20 Aug 2007 16:25:02 GMT, wrote:

In sci.physics John Larkin wrote:
On Sun, 19 Aug 2007 23:15:03 GMT, wrote:

In sci.physics John Larkin wrote:
On Sun, 19 Aug 2007 16:05:03 GMT, wrote:

In sci.physics Arny Krueger wrote:

"Ken Weitzel" wrote in message
news:IsPxi.68411$_d2.64084@pd7urf3no...

I do not know if the tracking
radar and cop's radar gun were on the same band, however I do know that
1MW of microwaves was sufficiently nondiscriminatory at the receiving
end to burn out its front end.

I bet it was sufficiently nondiscriminatory at the receiving end to
burn out the cop's front end, too.

When people talk about megawatt radars, they are talking pulse peak powers.
Radar pulses are very narrow - less than a microsecond. However, its peak
voltage that usually frys semiconductors.

If these megawatt-rated radars were not sending out short pulses, but
continuous power, they'd have to build a commerical electrical generating
plant next to them to run them in the field.

Nike HIPAR, 10.4 MW, pulse width 6 microseconds.

The array radars on the F-22 and JSF are reported to hit gigawatts
peak, and may one day get into the terawatt range. That would be
enough to fry the electronics on any current-generation missile or
plane, and maybe leave tanks and ships dead and immobile. And make
stealth planes un-stealthy at 100 mile ranges.

BAE is developing some of the laser-fired switches that make the peak
power.

John

A gigawatt at what pulse repetition rate; 1 pulse per hour?

Dunno, but high enough to be useful in a combat jet.

It may be near a gigawatt ERP, but I doubt that's watts RF into the
antenna.

No, that's real power. The planes are tiled with a bunch of 4" square
transmitter/antenna things, pulsing something like 100 megawatts each.
Google words like hpm weapon, array radar, e-bomb, BAE, F-22.

I'd also like to know what you'd use for waveguide at those power
levels. It's hard enough to keep moderate megawatts contained and
the waveguide in one piece.

I'd imagine lots of people would like to know that stuff.

John

OK, you're not talking about a radar, you're talking about an EMP
weapon.

It's apparently both. Plus it seems to be able to blast all available
data to a satellite so headquarters has a full 3D view of the entire
theatre, everything all the planes and drones can see.

I find a combined radar/weapon in something the size of a fighter
a little hard to believe.

So google it and believe what you will.

Little problems like how do you store energy on the order of hundreds
of megawatts and how do you transfer it to the RF generators in
nanoseconds. Wires have inductance.

Each of the tiles apparently has local capacitive energy storage and a
a laser-triggered switch that dumps the cap energy into the antenna,
probably as a UWB ringing impulse. I've seen a blurred pic of the BAE
switch, and it looks like a small strip of amorphous material
(possibly doped diamond?) on a ceramic substrate. High peak power
laser-triggered semiconductor switches have been around for a decade
at least. 10KV x 10KA = 100 MW, not unreasonable if you've got G$ to
spend.

http://advancednano.blogspot.com/200...s-warfare.html

http://en.wikipedia.org/wiki/F-35_Li...energy_weapons

http://www.dsta.gov.sg/DSTA_horizons/2005/03_1.htm

Cool stuff.

John