The 9-centimeter band is a portion of the SHF (microwave) radio spectrum internationally allocated to amateur radio and amateur satellite use. The amateur radio band, in ITU regions 1 and 2, is between 3,300 MHz and 3,500 MHz, and it is available only on a secondary basis. The amateur satellite band is between 3,400 MHz and 3,410 MHz, and it is only available in ITU Regions 1 and 2, on a non-interference basis to other users (ITU footnote 5.282). In Germany and Israel, the band 3,400 - 3,475 MHz is also allocated to the amateur service on a secondary basis (ITU footnote 5.431).
In the US, the FCC proposes to remove the amateur service (among other users) from this band for the purposes of 5G cellular system expansion. There have been many objections to this proposal by Amateur Radio operators, including the ARRL.
This section needs expansion with:
List of notable frequencies
- 3,400.1 MHz IARU Region-1 Calling frequency and Global EME center of activity
- 3,456.1 MHz IARU Region 2 Calling Frequency
3,332 - 3,339 MHz and 3345.8 - 3352.5 MHz are used by radio astronomers for spectral line observations. Amateur stations voluntarily avoid using these frequencies when in geographic proximity to a radio telescope. ITU footnote 5.149 encourages all radio communications in the band to take practical steps to avoid harmful interference to radio astronomy observations in those frequency ranges.
Countries with more restricted allocation
The Swedish Post and Telecom Authority (PTS) does not consider 3.4 GHz to be an amateur band, and has therefore auctioned it off for 5G test use. Temporary permits in the 3400 - 3401 MHz range are currently issued however.
The Ministerio de Economía y Empresa does not allow 3.4 GHz to be used by amateurs. Currently this band is used by WiMax in Spain and will be soon used by 5G services.
- "FCC Online Table of Frequency Allocations" (PDF). 47 C.F.R. Federal Communications Commission. August 13, 2015. Retrieved October 27, 2015.
Blondeel Timmerman, Hans (15 March 2009). "3300-3500 MHz". International Amateur Radio Union Region 1 Homepage. International Amateur Radio Union Region 1. Retrieved August 4, 2011.
EU17: In the sub-bands 3400-3410 MHz, 5660-5670 MHz, 10.36-10.37 GHz and 10.45-10.46 GHz the amateur service operates on a secondary basis. In making assignments to other services, CEPT administrations are requested wherever possible to maintain these sub-bands in such a way as to facilitate the reception of amateur emissions with minimal power flux densities.
- "VHF Managers Handbook". 7. International Amateur Radio Union Region 1. January 2015. p. 48. Archived from the original (PDF) on June 17, 2018. Retrieved October 27, 2015.
- "ARRL to Argue for Continued Access to 3-GHz Spectrum as FCC Sets Comment Deadlines". Amateur Radio Relay League. 24 January 2020. Retrieved 28 February 2020.
- "IARU Region 2 Band Plan" (PDF). International Amateur Radio Union Region 2. October 14, 2016. p. 13.
- "VUSHF Frequencies in Sweden V5.0" (PDF). Föreningen Sveriges Sändareamatörer (SSA). February 9, 2017. p. 25. Retrieved September 27, 2017.
|Range||Band||ITU Region 1||ITU Region 2||ITU Region 3|
|LF||2200 m||135.7–137.8 kHz|
|MF||630 m||472–479 kHz|
|160 m||1.810–1.850 MHz||1.800–2.000 MHz|
|HF||80 / 75 m||3.500–3.800 MHz||3.500–4.000 MHz||3.500–3.900 MHz|
|60 m||5.3515–5.3665 MHz|
|40 m||7.000–7.200 MHz||7.000–7.300 MHz||7.000–7.200 MHz|
|30 m[w]||10.100–10.150 MHz|
|20 m||14.000–14.350 MHz|
|17 m[w]||18.068–18.168 MHz|
|15 m||21.000–21.450 MHz|
|12 m[w]||24.890–24.990 MHz|
|10 m||28.000–29.700 MHz|
|VHF||6 m||50.000–52.000 MHz
|4 m[x]||70.000–70.500 MHz||N/A|
|2 m||144.000–146.000 MHz||144.000–148.000 MHz|
|1.25 m||N/A||220.000–225.000 MHz||N/A|
|UHF||70 cm||430.000–440.000 MHz||430.000–440.000 MHz|
|33 cm||N/A||902.000–928.000 MHz||N/A|
|23 cm||1.240–1.300 GHz|
|13 cm||2.300–2.450 GHz|
|SHF||9 cm||3.400–3.475 GHz[y]||3.300–3.500 GHz|
|5 cm||5.650–5.850 GHz||5.650–5.925 GHz||5.650–5.850 GHz|
|3 cm||10.000–10.500 GHz|
|1.2 cm||24.000–24.250 GHz|
|EHF||6 mm||47.000–47.200 GHz|
|4 mm[y]||75.500 GHz[x] – 81.500 GHz||76.000–81.500 GHz|
|2.5 mm||122.250–123.000 GHz|
|2 mm||134.000–141.000 GHz|
|1 mm||241.000–250.000 GHz|
|THF||Sub-mm||Some administrations have authorized spectrum for amateur use in this region;|
others have declined to regulate frequencies above 300 GHz, leaving them available by default.
[w] HF allocation created at the 1979 World Administrative Radio Conference. These are commonly called the "WARC bands".
|See also: Radio spectrum, Electromagnetic spectrum|