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0 pointsblurbleblurble5y ago0 comments

Thank you for this interesting comment!

When you say "continuous", would you consider some very high frequency solid state switching amplifier to be "continuous" enough for this application? I realize it's a different order of magnitude, but those GaN/Si transformers make me wonder if we aren't far off from some kind of megawatt scale solid state amplifier shakeup...

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tgflynn5y ago

It's conceivable. I've seen solid state RF amplifier modules successfully combined into some quite high power units and that was over 20 years ago. I haven't followed the technology since so I'm not up to date on that at all. In any case I think a 10 MW amplifier and associated power supplies and cooling equipment would need to be large and heavy.

A single jet engine generates about 20 MW of power and I'd be very surprised if you could pack 10 MW of RF amplifier into that kind of size and weight envelope.

blurbleblurbleOP5y ago

Makes sense. Maybe we'll see a fusion plasma thruster before the power/energy storage shrunk enough to make this viable as is (in the atmosphere and gravity of Earth at least).

RachelF5y ago

Most high power microwave devices aren't build on semiconductors like Silicon (solid state), yet. They are normally valves of some sort, like magnetrons, klystrons or travelling wave tubes.

Some radars would be in the mega-watt range, but only pulsed with low duty cycles or 1%.

tgflynn5y ago

It sounds like the technology hasn't evolved much in the last 20-30 years then.

Around 1995 I was involved with a project where an engineer designed and built a multi-kW CW (I don't recall the exact value) pre-amp out of transistor based modules. There was a plan to apply the same approach to a later project at much higher power levels (100's of kW's) where the conventional approach would have been to use a klystron. I left that team (and the field) though so I don't know if the larger version was ever successfully implemented.

EDIT: I should note that this wasn't in the microwave regime, it was 500 MHz.

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tgflynn5y ago

A single jet engine generates about 20 MW of power and I'd be very surprised if you could pack 10 MW of RF amplifier into that kind of size and weight envelope.

blurbleblurbleOP5y ago

Makes sense. Maybe we'll see a fusion plasma thruster before the power/energy storage shrunk enough to make this viable as is (in the atmosphere and gravity of Earth at least).

RachelF5y ago

Most high power microwave devices aren't build on semiconductors like Silicon (solid state), yet. They are normally valves of some sort, like magnetrons, klystrons or travelling wave tubes.

Some radars would be in the mega-watt range, but only pulsed with low duty cycles or 1%.

tgflynn5y ago

It sounds like the technology hasn't evolved much in the last 20-30 years then.

EDIT: I should note that this wasn't in the microwave regime, it was 500 MHz.

j / k navigate · click thread line to collapse