2.4GHz communication

Antenna 2.4Ghz – for ground station helical antenna design and manufacturing – it will be better to print such antenna than make it by hands – 3D printing material suitable is Nylon 12. Two 3D printing facilities : Ponoko: http://www.ponoko.com/design-your-own/products/2-4ghz-ground-antena-6246 and Shapeways: http://www.shapeways.com/model/322767/2_4ghz_antena.html?gid=sg85851 . After printing all what will be left - to connect flat reflector made from PCB board, and 0.3 dia wire. For mockup of a testing antenna on CubeSat (that one has to be made by hands) 3d model: http://www.shapeways.com/model/322768/small_2_4ghz_antena__for_cubesat_.html?gid=sg85851 or http://www.ponoko.com/design-your-own/products/2-4-ghz-antena-for-cudesat--6245
2.4Ghz band is actually a junk band but according FCC ((http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&tpl=/ecfrbrowse/Title47/47cfr15_main_02.tpl ) and in Canada http://www.ic.gc.ca/eic/site/smt-gst.nsf/vwapj/rss210-issue7.pdf/$FILE/rss210-issue7.pdf it is possible without license to use 4wt (Canada) and in 1wt (USA) transmitters (assuming BlueTooth as a core), without limitation on antennas. For local noise cancellation microchip is: http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=QHX220IQT7CT-ND According spec >20dB noise cancellation possible. Manually (which is proved and possible) for ground station can be achievable 50dB noise (junk) suppression.

Also was discussed the same technique for suppress noise on a transmitter – transmitter antenna on satellite oriented to the point on the earth at the same time noise helical antenna looks backward 180 degree. Second (noise) antenna needs to be with receiving pattern covering the same sky area as a ground antenna (this depend on a orbit, otherwise needs mechanical adjustment). Mixing delayed (61.3mm) noise on 2.4Ghz from a particular place on a sky with a transmitting signal, then subtracting same noise on receiver can give ~50+20=70 dB which will be good as it sounds. Complications: see more on: http://www.adobri.com/ProjectCr.aspx

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