Re:Plasma Antenna
by lachlan-sneff on Tuesday September 10, 2019 @08:47PM
(#20935503)
What a cool visual. Setting up a small beacon like object on the ground, standing back a couple hundred feet, and then a beam of bright blue light bursts several kilometers into the air, sending a quick burst of data while the capacitors powering it can keep it alive.
Re:Plasma Antenna
by logfromblammo on Wednesday September 11, 2019 @10:15AM
(#20940448)
If using multiple converging lasers, the antenna need not be connected to the equipment. Two lasers could ionize the air in a line 2500m long, and a third could excite the center of it in a modulated fashion. That would be transmit only, unless you had some way to measure the energy levels at that center point from a distance.
It would be unlikely to glow brightly enough in the visual spectrum to see in the daytime, but it would be pretty cool at night.
When the plasma antenna is turned off, it stops existing. There's nothing there to attack or detect.
A possible future advantage would be shaping the plasma with magnetic fields, to create customizable antenna geometries, or geometries that electrically extend beyond the physical bounds of the equipment. Imagine using a laser small enough to fit in a backpack to create a 1/4 wave antenna long enough to transmit or receive at 30 kHz, with length 2.5 km .
You could create a plasma antenna 2500m long, send a message to a submarine 150 m below the surface, then it just disappears when you turn it off.