"A new type of pocket-sized antenna, developed at the Department of Energy's SLAC National Accelerator Laboratory, could enable mobile communication in situations where conventional radios don't work, such as under water, through the ground and over very long distances through air.
The device emits very low frequency (VLF) radiation with wavelengths of tens to hundreds of miles. These waves travel long distances beyond the horizon and can penetrate environments that would block radio waves with shorter wavelengths. While today's most powerful VLF technology requires gigantic emitters, this antenna is only four inches tall, so it could potentially be used for tasks that demand high mobility, including rescue and defense missions...
...To generate VLF radiation, the device exploits what is known as the piezoelectric effect, which converts mechanical stress to a buildup of electrical charge.
The researchers used a rod-shaped crystal of a piezoelectric material, lithium niobate, as their antenna. When they applied an oscillating electric voltage to the rod it vibrated, alternately shrinking and expanding, and this mechanical stress triggered an oscillating electric current whose electromagnetic energy then got emitted as VLF radiation...
...The researchers also found a clever way of tweaking the wavelength of the emitted radiation, he said: "We repeatedly switch the wavelength during operation, which allows us to transmit with a large bandwidth. This is key to achieving data transfer rates of more than 100 bits per second—enough to send a simple text."
VIA : SLAC develops novel compact antenna for communicating where radios fail
If this had posted 11 days earlier, I'd be more suspicious. Perhaps a new project for @Lauri-Coyote's ranchland?
Considering all the discussions on RR about "magic antennas and the laws of physics", I'll reserve judgement until more information becomes available. Novel idea though.
The device emits very low frequency (VLF) radiation with wavelengths of tens to hundreds of miles. These waves travel long distances beyond the horizon and can penetrate environments that would block radio waves with shorter wavelengths. While today's most powerful VLF technology requires gigantic emitters, this antenna is only four inches tall, so it could potentially be used for tasks that demand high mobility, including rescue and defense missions...
...To generate VLF radiation, the device exploits what is known as the piezoelectric effect, which converts mechanical stress to a buildup of electrical charge.
The researchers used a rod-shaped crystal of a piezoelectric material, lithium niobate, as their antenna. When they applied an oscillating electric voltage to the rod it vibrated, alternately shrinking and expanding, and this mechanical stress triggered an oscillating electric current whose electromagnetic energy then got emitted as VLF radiation...
...The researchers also found a clever way of tweaking the wavelength of the emitted radiation, he said: "We repeatedly switch the wavelength during operation, which allows us to transmit with a large bandwidth. This is key to achieving data transfer rates of more than 100 bits per second—enough to send a simple text."
VIA : SLAC develops novel compact antenna for communicating where radios fail
If this had posted 11 days earlier, I'd be more suspicious. Perhaps a new project for @Lauri-Coyote's ranchland?
Considering all the discussions on RR about "magic antennas and the laws of physics", I'll reserve judgement until more information becomes available. Novel idea though.
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