ARLA/CLUSTER: Antenas em metamateriais*.

[João Gonçalves Costa]

[http://www.personadondada.com/wordpress/wp-content/uploads/2008/11/invisibility_cloak.jpg]

'Invisibility cloak' antennas

The materials used to make real-life invisibility cloaks could also make antennas smaller.

New Scientist reports that "an international team of physicists has now created metamaterials that can be tuned to a range of different frequencies as required. A cellphone antenna fashioned from the new material could be tuned to work very efficiently across a small frequency range, but retuned to a different band for roaming."

"Because metamaterials can manipulate electromagnetic waves to a greater degree than normal materials - and even bend light "backwards" - a small metamaterial antenna is as effective as a much larger standard antenna at transmitting or receiving waves."

"But a narrowband metamaterial antenna has its drawbacks - it's rare that engineers require an antenna tuned to just one frequency, for instance, different countries have allocated different frequency bands to their cellphone networks. A tunable metamaterial antenna could allow a wireless gadget to work "outstandingly well" at the frequencies used in one country, but also carry the option of retuning for use abroad."

Read the New Scientist article - 'Invisibility cloak' antennas could shrink cellphones - at
http://www.newscientist.com/article/dn17660-invisibility-
cloak-antennas-could-shrink-cellphones.html

Active invisibility cloaks could work at many wavelengths
http://www.embedded.com/219400692?cid=NL_embedded

*Um Metamaterial é um material produzido artificialmente e que é dotado de propriedades que não existem na natureza.
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