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Magnetoelectric antennas could transform how underwater robots talk

30 points • by breve • last Sunday at 10:38 AM • 14 comments • view on HN

Comments

gus_massa • last Monday at 1:59 AM

I was wondering how this could make sense until:

The result is an antenna that operates at very low frequencies, around 35–36 kHz, while remaining far more compact than the conventional electrical antennas that work at those same frequencies.

They are using a super low frequency.

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raffael_de • today at 11:11 AM

my first association here would be steering of torpedoes. the US Navy must have been on this for decades and very deep pockets.

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cyanydeez • last Sunday at 4:21 PM

youd think optic fiber like Ukraine is diing would be viable to some extent.

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peter_d_sherman • today at 10:45 AM

"At 36 kHz, the wavelength shrinks from roughly 8,327 m (27,320 ft) in air to just 170 m (558 ft) in freshwater..."

Yes, waves apparently compress or expand depending on the medium they are in...

I'm curious as to what the extremes of potential medium might be... on one end, we might have the densest of heavy metals and on the other, we might have the vacuum of outer space...

Also, what role does/would temperature play?

If a heavy metal was frozen and its temperature brought as close to absolute zero as possible, then would that shrink or expand any propagated waves through it, if even by the smallest amount?

Also, if so, might there be a definable relationship between that phenomena, if it exists, and superconductivity?

Anyway, great article, and it's interesting to learn about Magnetoelectric Antennas!

(I had never heard about them before!)

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