W band

<h2 id="radar">Radar</h2>
<p>A number of passive millimeter-wave cameras for concealed weapons detection operate at 94 GHz. A frequency around 77 GHz is used for <a href="/facts/Autonomous_cruise_control_system/tnoAo9U1">automotive cruise control radar</a>. The atmospheric <a href="/facts/Radio_window/rdgooP8G">radio window</a> at 94 GHz is used for imaging millimeter-wave radar applications in astronomy, defense, and security applications.
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<h2 id="heat-ray">Heat ray</h2>
<p>Less-than-lethal weaponry exists that uses millimeter waves to heat a thin layer of human skin to an intolerable temperature so as to make the targeted person move away. A two-second burst of the 95 GHz focused beam heats the skin to a temperature of 130 °F (54 °C) at a depth of 1⁄64 of an inch (0.40 mm). The <a href="/facts/United_States_Air_Force/7MxWBYlc">United States Air Force</a> and <a href="/facts/United_States_Marine_Corps/J8JDlJG2">Marines</a> are currently using this type of <a href="/facts/Active_Denial_System/tXpa5PR4">Active Denial System</a>.<a class="footnote-ref" id="fnref:1" href="#fn:1"><sup>1</sup></a>
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<h2 id="communications">Communications</h2>
<p>In terms of communications capability, W band offers high data rate throughput when used at high altitudes and in space. (The 71–76 GHz / 81–86 GHz segment of the W band is allocated by the <a href="/facts/International_Telecommunication_Union/Yn8UKKkw">International Telecommunication Union</a> to satellite services.) Because of increasing spectrum and orbit congestion at lower frequencies, W-band satellite allocations are of increasing interest to commercial satellite operators, especially the Starlink satellite constellations which have implemented capabilities in these bands.
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<h2 id="further-reading">Further reading</h2>
<ul><li>5th Framework Programme Information Societies Technologies (IST) - Multifunctional Automotive Radar Network (RadarNet) <a href="http://www.radarnet.org/publications/zip/its_paper.pdf">[1]</a></li>
<li>Appleby, Roger; Anderton, Rupert N.; Thomson, Neil H.; Jack, James W. (2004). "The design of a real-time 94-GHZ passive millimetre-wave imager for helicopter operations". In Appleby, Roger; Chamberlain, J. Martyn; Krapels, Keith A. (eds.). <i>Passive Millimetre-Wave and Terahertz Imaging and Technology</i>. Vol. 5619. p. 38. <a href="/facts/Doi_(identifier)/muM9Etpq">doi</a>:<a href="https://doi.org/10.1117%2F12.581336">10.1117/12.581336</a>.</li>
<li>Chen, Zhiming; Wang, Chun-Cheng; Yao, Hsin-Cheng; Heydari, Payam (2012). "A BiCMOS W-Band 2×2 Focal-Plane Array with On-Chip Antenna". <i>IEEE Journal of Solid-State Circuits</i>. 47 (10): 2355–2371. <a href="/facts/Bibcode_(identifier)/9HtdQSGB">Bibcode</a>:<a href="https://ui.adsabs.harvard.edu/abs/2012IJSSC..47.2355C">2012IJSSC..47.2355C</a>. <a href="/facts/Doi_(identifier)/muM9Etpq">doi</a>:<a href="https://doi.org/10.1109%2FJSSC.2012.2209775">10.1109/JSSC.2012.2209775</a>.</li>
<li>Gilreath, Leland; Jain, Vipul; Heydari, Payam (2011). "Design and Analysis of a W-Band Si <i>Ge</i> Direct-Detection-Based Passive Imaging Receiver". <i>IEEE Journal of Solid-State Circuits</i>. 46 (10): 2240–2252. <a href="/facts/Bibcode_(identifier)/9HtdQSGB">Bibcode</a>:<a href="https://ui.adsabs.harvard.edu/abs/2011IJSSC..46.2240G">2011IJSSC..46.2240G</a>. <a href="/facts/Doi_(identifier)/muM9Etpq">doi</a>:<a href="https://doi.org/10.1109%2FJSSC.2011.2162792">10.1109/JSSC.2011.2162792</a>.</li></ul>
<h2 id="external-links">External links</h2>
<ul><li><a href="https://web.archive.org/web/20090705010355/http://www.ecdl.tkk.fi/research/projects/94cpr.php?lang=en">A cloud radar at 94 GHz</a></li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>"Raytheon's Silent Guardian millimeter wave weapon". <a href="http://www.raytheon.com/newsroom/feature/ads_03-08/" target="_blank">http://www.raytheon.com/newsroom/feature/ads_03-08/</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
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W band open-in-new

W band