<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0"
	xmlns:content="http://purl.org/rss/1.0/modules/content/"
	xmlns:wfw="http://wellformedweb.org/CommentAPI/"
	xmlns:dc="http://purl.org/dc/elements/1.1/"
	xmlns:atom="http://www.w3.org/2005/Atom"
	xmlns:sy="http://purl.org/rss/1.0/modules/syndication/"
	xmlns:slash="http://purl.org/rss/1.0/modules/slash/"
	>

<channel>
	<title>Antenna Design Consultant</title>
	<atom:link href="http://www.antennadesignconsultant.com/feed/" rel="self" type="application/rss+xml" />
	<link>http://www.antennadesignconsultant.com</link>
	<description>Glaser Associates</description>
	<lastBuildDate>Wed, 25 Aug 2010 22:26:45 +0000</lastBuildDate>
	<language>en</language>
	<sy:updatePeriod>hourly</sy:updatePeriod>
	<sy:updateFrequency>1</sy:updateFrequency>
	<generator>http://wordpress.org/?v=3.0.1</generator>
		<item>
		<title>How can you make any object invisible to radar at a given frequency?</title>
		<link>http://www.antennadesignconsultant.com/hello-world/</link>
		<comments>http://www.antennadesignconsultant.com/hello-world/#comments</comments>
		<pubDate>Mon, 16 Aug 2010 16:20:04 +0000</pubDate>
		<dc:creator>admin</dc:creator>
				<category><![CDATA[Uncategorized]]></category>

		<guid isPermaLink="false">http://www.antennadesignconsultant.com/?p=1</guid>
		<description><![CDATA[All you need to do is to place on a closed surface surrounding the object an electric surface current distribution Ke = nxH (Amp/Meter), and magnetic current distribution Km = -nxE (Volt/Meter) , where E and H are the time-varying &#8230; <a href="http://www.antennadesignconsultant.com/hello-world/">Continue reading <span class="meta-nav">&#8594;</span></a>]]></description>
			<content:encoded><![CDATA[<p>All you need to do is to place on a closed surface surrounding the object an electric surface current distribution <strong>Ke = nxH (Amp/Meter)</strong>, and magnetic current distribution <strong>Km = -nxE (Volt/Meter)</strong> , where E and H are the time-varying electric and magnetic fields of the radar on the object surface, and n is the outward normal to the surface, x denotes vector cross product.  The resulting electromagnetic fields are the same as the original electromagnetic fields outside the object and <strong>E = 0, H = 0</strong> inside the object. This is guaranteed by Love’s Equivalence Theorem. [1]. Therefore, the scattered fields have been eliminated!</p>
<p>The difficult problem remains: to generate the required electric and magnetic current distributions on the closed surface. The electric current sheet can be achieved by curved conducting wires driven by a current source. The magnetic current sheets are much more difficult to realize but can be approximated as a doublet of two electric surface currents fed by oppositely directed current sources. [2], [3], [4].  (Patent pending, 6/17/2010)</p>
<p>Example of a metal sphere of radius R illuminated by a plane wave<br />
E = e<sup>-jωz</sup>/c (0, 1, 0), H = -(1/Zo) e-<sup>jωz</sup>/c (1,0,0), Zo=377 ohms,  ω = angular frequency, c = speed of light</p>
<p>This can be converted into spherical coordinates<br />
Ke on the sphere = n x H = e<sup>-jωz</sup>/c ((z/R), 0, (x/R)}<br />
Km on the sphere = -n x E = e<sup>-jωz</sup>/c ((0, (-z/R)), (y/R))</p>
<p>Where x = Rsin(θ)sin(φ), y = Rsin(θ)cos(φ), z = Rcos(θ)<br />
.<br />
These equations simplify for the magnitude of the currents.  Οn the sphere, in the x-z plane, <strong>|Ke|</strong> are circles, ((1 – (y/R)2)0.5 and in the y-z plane,  <strong>|Km|</strong> are also circles ((1 – (x/R)2)0.5.<br />
The phase factors are given by  e<sup>-jωz</sup>/c</p>
<p>More ideas on how to realize these currents will be given in the next blog.<br />
1.    A. E. H. Love, “The Integration of Equations of Propagation of Electric Waves,” Phil. Trans. Roy. Soc. London, Ser A, 197, 1901, pp. 1 – 45.<br />
2.    S. A. Schelkunoff, “Some Equivalence Theorems of Electromagnetics and Their Application to Radiation Problems,” Bell System Technical Journal, Vol. 15, 1936, pp. 92 – 112<br />
3.    S. Rengarajan, Y. Rahmat-Samii, “The Field Equivalence of the Non-Intuitive Null Fields, “ IEEE Trans. on Antennas and Propagation Magazine, Vol. 42, No. 4, August 2000<br />
4.    S. A. Schelkunoff, “Antennas Theory and Practice,” John Wiley &amp; Sons, NY, 1952,  pp. 44 -45.</p>
]]></content:encoded>
			<wfw:commentRss>http://www.antennadesignconsultant.com/hello-world/feed/</wfw:commentRss>
		<slash:comments>1</slash:comments>
		</item>
	</channel>
</rss>
