Dave replied the topic: Anti Air Microwave Weapon

Hi,

Your question is strikingly similar to a thread from 6 months ago

I think that'll answer your initial questions; have a look and let us know if it raises any more.

Henderson replied the topic: Anti Air Microwave Weapon

Yes, the thread has a lot of great data, thank you. With the mention of microwave frequency, I figure the aliens can range-find the target then use the frequency which gives them the most power at the given range (possibly adjusting the frequency as the target moves closer/farther).


My main question if I may, is how vulnerable aircraft would be to microwaves. China's defence system is said to be effective against missiles and tanks, but we can only guess at its capabilities. For my story's purposes, it doesn't matter if the aliens can't fry military aircraft circuitry with their masers (that's what the electro part of the electro-maser is for).

I'm afraid I don't properly understand how microwaves cause shorts in electronics, I had thought they built up charge. Originally the plan was that the microwaves would build up charge on the plane's skin, then the electricity would hit the plane with the opposite charge and react. According to the person I spoke to, microwaves don't build up charge, and they can't build up charge in the plane's skin, so I'm wondering if this system will work, or if it would require an impossible amount of power.


Thank you. sorry for my ignorance.

Dave replied the topic: Anti Air Microwave Weapon

Hi,

On frequencies: for most power at the given range, you'll be at the lowest frequency. That's due to atmospheric propagation losses, which increase with frequency, and the difficulty of generating high power as the frequency increases.

There are different levels of vulnerability:
First, your receiver is vulnerable to interference. Even a relatively low signal at close range can introduce errors in a digital receiver. And if you've ever listened to AM radio during a thunderstorm, the shot of static every time lightning strikes is another example of interference. It doesn't damage anything, but information is not getting through.

Moving up a little, higher level signals can overwhelm your receiver input. A good receiver will have some protection against that, so that the outcome is similar to the first scenario - nothing's damaged, but information's not flowing. At a certain level though, the components will be damaged. This won't cause the aircraft to fall out of the sky necessarily, but they might lose a critical capability. When you talk about changing frequencies, this is one area where it makes sense - you might have your antagonists tune their emitters to the right frequencies to black out the protagonist's entire communications system.

The next step up is the big one. At this level, you're not entering the system through the radio front end, but through any and every crack and crevice in the vehicle skin. A couple of loose screws is enough to let these signals through and cause untold damage. Because once they're through the skin, you're talking about voltages that far exceed the breakdown voltage of the components on the board. All of a sudden the board is fried. And because we're no longer limited to entering through an antenna, it could be any board, like an engine management computer or a flight control computer. Now you're talking about the aircraft falling out of the sky.

Of course to do that, you need to hit the aircraft with a whole lot of broadband energy, like the electromagnetic pulse from a high altitude nuclear detonation. I would guess that the Chinese system you referred to is probably doing a smaller-scale version of that. As you've noted, aircraft are designed to withstand that sort of thing in the form of lightning strikes. But this is the region you'd need to be in for your story.

My guess (and it's just a guess) is that to create a plasma channel you'd be up at gigawatt power levels. So if your aliens have mastered lightweight, controlled, compact, fusion reactors, it's plausible.

Happy writing :)

Henderson replied the topic: Anti Air Microwave Weapon

Thank you Dave.

With the plasma channel, it depends if microwaves are as efficient as other lasers

https://www.youtube.com/watch?time_continue=7&v=Kld3TuqsMkE

https://youtu.be/9tJF3qBWyUk

If masers can't produce this effect, I won't be able to use them for this.