AN/APG-78 Longbow MMR's operating band as listed in DB3K 497a is J-band, but according to the manufacturer, it is actually K-band (IEEE Ka-band to be specific). According to NATO's radio frequencies band designation, J-band has a frequency spanning from 10-20 GHz, where K-band spans 20-40 GHz. The obsolete NATO designation assigned Ka-band with a frequency ranging from 20-36 GHz. So even if the manufacturer refers to the old NATO Ka-band, J-band would be right on 20 GHz, a transitional edge between old NATO Ku and Ka-band.
But since Northrop Grumman's official AN/APG-78 leaflet was published in 2007 and Lockheed Martin published one in 2019, they're definitely referring to IEEE's Ka-band (27-40 GHz) as NATO no longer use Ku and Ka letters in its nomenclature. Also, AN/APG-78 is advertised as a millimeter-wave radar, which would mean its wavelength must be between 1-10 millimeter, J-band's wavelength at its shortest is 15 millimeter, which means the radar can't be operating in J-band.
Jkryos
commented
1 year ago
DB Selector
DB3K
Affected DBID(s)
Sensor 602
Summary of Changes
AN/APG-78 Longbow MMR's operating band as listed in DB3K 497a is J-band, but according to the manufacturer, it is actually K-band (IEEE Ka-band to be specific). According to NATO's radio frequencies band designation, J-band has a frequency spanning from 10-20 GHz, where K-band spans 20-40 GHz. The obsolete NATO designation assigned Ka-band with a frequency ranging from 20-36 GHz. So even if the manufacturer refers to the old NATO Ka-band, J-band would be right on 20 GHz, a transitional edge between old NATO Ku and Ka-band.
But since Northrop Grumman's official AN/APG-78 leaflet was published in 2007 and Lockheed Martin published one in 2019, they're definitely referring to IEEE's Ka-band (27-40 GHz) as NATO no longer use Ku and Ka letters in its nomenclature. Also, AN/APG-78 is advertised as a millimeter-wave radar, which would mean its wavelength must be between 1-10 millimeter, J-band's wavelength at its shortest is 15 millimeter, which means the radar can't be operating in J-band.
Sources
EU, NATO, US ECM Frequency Designations --- Page indexed by Google more than 10 years ago
Official Northrop Grumman and Lockheed Martin Longbow Leaflet --- Page indexed by Google more than 10 years ago, archived by radartutorial.eu
Lockheed Martin Official Product Card - Lowbow FCR --- Page indexed by Google more than 10 years ago