These antennas only work when energized, effectively vanishing when turned off, with the plasma reverting back to normal gas. This is key for stealth on the battlefield — metal antennas can scatter incoming radar signals, giving away their presence.
In addition, to counteract jamming attempts, plasma antennas can rapidly adjust which frequencies they broadcast and pick up by changing how much energy the plasma is given. This way, they avoid interference from enemy signals. Metal antennas, on the other hand, are each forced to receive and transmit only a given range of frequencies, making them vulnerable to jamming.
The fact that plasma antennas can get reconfigured to broadcast and receive a wide range of frequencies also means “you can create a kind of ‘all-in-one’ antenna, with one plasma antenna performing the jobs of several metal antennas,” researcher Theodore Anderson, CEO of plasma antenna company Haleakala R&D in Brookfield, Mass., told LiveScience. “We’re pursuing telecommunications as well as military applications.”
The gas is currently in glass tubes, but they’re researching ceramic tubes. I’m no expert, but I’m thinking glass antennas aren’t going to cut it on the battlefield.