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.
Very low frequency radio waves is the traditional means of communication with military submarines, while submerged.
However, this required huge antennas and very high power transmitters, so this was used mainly to transmit short messages from a terrestrial station to submarines, for instance instructing them to send an antenna to the surface, for bidirectional communication at high speed.
The innovation here is the use of a new kind of antenna, which can work well under water despite small dimensions, and with which a low-power transmitter is sufficient for communication with other submarines or with a surface boat, up to a few hundred meters.
This uses the same principle, but the traditional method required immense antennas and very high power radio transmitters.
Such antennas and transmitters cannot be installed in a small submarine.
Here a new kind of antenna is used, which is efficient under water even at small dimensions, so it can be installed in small submarines, for communication at distances of up to a few hundred meter.
"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!
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.
However, this required huge antennas and very high power transmitters, so this was used mainly to transmit short messages from a terrestrial station to submarines, for instance instructing them to send an antenna to the surface, for bidirectional communication at high speed.
The innovation here is the use of a new kind of antenna, which can work well under water despite small dimensions, and with which a low-power transmitter is sufficient for communication with other submarines or with a surface boat, up to a few hundred meters.
Such antennas and transmitters cannot be installed in a small submarine.
Here a new kind of antenna is used, which is efficient under water even at small dimensions, so it can be installed in small submarines, for communication at distances of up to a few hundred meter.
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!)