Glenn
2014-01-11 10:34:50 UTC
(Svar til dk.fritid.hamradio )
Kunne man forestille sig at følgende kunne bane vejen for
ultraretningsbestemte små LB, MB og KB antenner? Dog er de indtil videre
utrolig lille båndbredde.
Men det er vel bare indtil der er nogen, som laver en antennekrydsning
mellen en fraktalantenne (fx "LPDA=Logaritmisk Periodisk Dipol Antenne")
og en metamaterialeantenne?
Hvem kan fortælle lidt om hvordan metamaterialer virker?:
https://da.wikipedia.org/wiki/Metamaterialeantenne
https://da.wikipedia.org/wiki/Metamateriale
https://da.wikipedia.org/wiki/Kategori:Metamaterialer
De har også tanker om at krydse "SAR[synthetic-aperture-radar]-chips"
med metamateriale linser - dvs elektronisk styrbare
ultraretningsbestemte små LB, MB og KB antenner?:
Duke University (2014, January 10). 'Superlens' extends range of
wireless power transfer. ScienceDaily:
http://www.sciencedaily.com/releases/2014/01/140110153201.htm
"...
But now, Duke University researchers have demonstrated the feasibility
of wireless power transfer using low-frequency magnetic fields over
distances much larger than the size of the transmitter and receiver.
...
"For the first time we have demonstrated that the efficiency of
magneto-inductive wireless power transfer can be enhanced over distances
many times larger than the size of the receiver and transmitter," said
Yaroslav Urzhumov, assistant research professor of electrical and
computer engineering at Duke University.
...
The geometry of the coils and their repetitive nature form a
metamaterial that interacts with magnetic fields in such a way that the
fields are transmitted and confined into a narrow cone in which the
power intensity is much higher.
...
"If your electromagnet is one inch in diameter, you get almost no power
just three inches away," said Urzhumov. "You only get about 0.1 percent
of what's inside the coil." But with the superlens in place, he
explained, the magnetic field is focused nearly a foot away with enough
strength to induce noticeable electric current in an identically sized
receiver coil.
...
"Most materials don't absorb magnetic fields very much, making them much
safer than electric fields," he said. "In fact, the FCC approves the use
of 3-Tesla magnetic fields for medical imaging, which are absolutely
enormous relative to what we might need for powering consumer
electronics. The technology is being designed with this increased safety
in mind."
...
He plans to build a dynamically tunable superlens, which can control the
direction of its focused power cone.
..."
Lidt i samme boldgade:
2. jan 2013, Usædvanlig magnetisk skal kan bane vejen for trådløs
energioverførsel:
http://ing.dk/artikel/usaedvanlig-magnetisk-skal-kan-bane-vejen-tradlos-energioverforsel-135264
/Glenn OZ1HFT
Kunne man forestille sig at følgende kunne bane vejen for
ultraretningsbestemte små LB, MB og KB antenner? Dog er de indtil videre
utrolig lille båndbredde.
Men det er vel bare indtil der er nogen, som laver en antennekrydsning
mellen en fraktalantenne (fx "LPDA=Logaritmisk Periodisk Dipol Antenne")
og en metamaterialeantenne?
Hvem kan fortælle lidt om hvordan metamaterialer virker?:
https://da.wikipedia.org/wiki/Metamaterialeantenne
https://da.wikipedia.org/wiki/Metamateriale
https://da.wikipedia.org/wiki/Kategori:Metamaterialer
De har også tanker om at krydse "SAR[synthetic-aperture-radar]-chips"
med metamateriale linser - dvs elektronisk styrbare
ultraretningsbestemte små LB, MB og KB antenner?:
Duke University (2014, January 10). 'Superlens' extends range of
wireless power transfer. ScienceDaily:
http://www.sciencedaily.com/releases/2014/01/140110153201.htm
"...
But now, Duke University researchers have demonstrated the feasibility
of wireless power transfer using low-frequency magnetic fields over
distances much larger than the size of the transmitter and receiver.
...
"For the first time we have demonstrated that the efficiency of
magneto-inductive wireless power transfer can be enhanced over distances
many times larger than the size of the receiver and transmitter," said
Yaroslav Urzhumov, assistant research professor of electrical and
computer engineering at Duke University.
...
The geometry of the coils and their repetitive nature form a
metamaterial that interacts with magnetic fields in such a way that the
fields are transmitted and confined into a narrow cone in which the
power intensity is much higher.
...
"If your electromagnet is one inch in diameter, you get almost no power
just three inches away," said Urzhumov. "You only get about 0.1 percent
of what's inside the coil." But with the superlens in place, he
explained, the magnetic field is focused nearly a foot away with enough
strength to induce noticeable electric current in an identically sized
receiver coil.
...
"Most materials don't absorb magnetic fields very much, making them much
safer than electric fields," he said. "In fact, the FCC approves the use
of 3-Tesla magnetic fields for medical imaging, which are absolutely
enormous relative to what we might need for powering consumer
electronics. The technology is being designed with this increased safety
in mind."
...
He plans to build a dynamically tunable superlens, which can control the
direction of its focused power cone.
..."
Lidt i samme boldgade:
2. jan 2013, Usædvanlig magnetisk skal kan bane vejen for trådløs
energioverførsel:
http://ing.dk/artikel/usaedvanlig-magnetisk-skal-kan-bane-vejen-tradlos-energioverforsel-135264
/Glenn OZ1HFT