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<H1>'Invisibility cloak' antennas</H1>
<P><FONT face=Verdana>The materials used to make real-life invisibility cloaks
could also make antennas smaller.</FONT></P>
<P><FONT face=Verdana><STRONG>New Scientist</STRONG> 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."</FONT></P>
<P><FONT face=Verdana>"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."</FONT></P>
<P><FONT face=Verdana>"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."</FONT></P>
<P><FONT face=Verdana>Read the New Scientist article - <EM>'Invisibility cloak'
antennas could shrink cellphones</EM> - at<BR></FONT><A
href="http://www.newscientist.com/article/dn17660-invisibility-cloak-antennas-could-shrink-cellphones.html"
target=_blank><FONT
face=Verdana>http://www.newscientist.com/article/dn17660-invisibility-<BR>cloak-antennas-could-shrink-cellphones.html</FONT></A></P>
<P><FONT face=Verdana>Active invisibility cloaks could work at many
wavelengths<BR></FONT><A
href="http://www.embedded.com/219400692?cid=NL_embedded" target=_blank><FONT
face=Verdana>http://www.embedded.com/219400692?cid=NL_embedded</FONT></A></P>
<P><FONT face=Verdana>*<FONT face="Times New Roman">Um <B>Metamaterial</B> é um
material produzido artificialmente e que é dotado de propriedades que não
existem na natureza.</FONT></FONT></P></BODY></HTML>