Re:Boeing, Airbus executives urge delay in U.S. 5G wireless ...
by onphonenow on Tuesday December 21, 2021 @06:31PM
(#29643435)
So a guard band of 300Mhz then? What's weird is that I'd expect an altimeter to be on the order of .1 to 2MHz bandwidth max. There's just something wrong in the math here.
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Re:Boeing, Airbus executives urge delay in U.S. 5G wireless ...
by drmpeg on Tuesday December 21, 2021 @07:59PM
(#29644201)
Radar altimeters use frequency modulated continuous wave (FMCW) and the bandwidth is 20 to 170 MHz (the larger the chirp, the more accurate it can be).
It's extremely difficult to have a 170 MHz wide filter at 4.3 GHz with a brick wall response out of band.
https://www.ntia.doc.gov/files/ntia/publications/compendium/...