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).^[1]

In CEPT's "European Common Allocation Table", footnote EU17 allocates 3,400 MHz to 3,410 MHz to European amateurs on a secondary basis.^[2]^[3]

In the US, the FCC is recommending removing the amateur service from this band in order to make room for the 5G cellular system. There have been many objections to this proposal by Amateur Radio operators, including the ARRL.^[4]

History

This section needs expansion with: Origin. You can help by adding to it. (January 2012)

List of notable frequencies

3,400.1 MHz IARU Region-1 Calling frequency^[3] and Global EME center of activity^[3]^[5]
3,456.1 MHz IARU Region 2 Calling Frequency^[5]

Radio Astronomy

3,332 - 3,339 MHz and 3345.8 - 3352.5 MHz are used by radio astronomers for spectral line observations.^[5] 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.^[1]

Countries with more restricted allocation

Sweden

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.^[6]

Spain

The Ministerio de Asuntos Económicos y Transformación Digital does not allow 3.4 GHz to be used by amateurs. Currently this band is used by 5G services.

References

^ ^a ^b "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.
^ ^a ^b ^c "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.
^ ^a ^b ^c "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.

International amateur radio frequency allocations^[v]

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
MF	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 (50.000–54.000 MHz)^[y]	50.000–54.000 MHz
	4 m^[x]	70.000–70.500 MHz	—
	2 m	144.000–146.000 MHz	144.000–148.000 MHz
	1.25 m	—	220.000–225.000 MHz	—
UHF	70 cm	430.000–440.000 MHz	430.000–440.000 MHz (420.000–450.000 MHz)^[y]
	33 cm	—	902.000–928.000 MHz	—
	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.
[v] All allocations are subject to variation by country. For simplicity, only common allocations found internationally are listed. See a band's article for specifics. [w] HF allocation created at the 1979 World Administrative Radio Conference. These are commonly called the "WARC bands". [x] This is not mentioned in the ITU's Table of Frequency Allocations, but many individual administrations have commonly adopted this allocation under "Article 4.4". [y] This includes a currently active footnote allocation mentioned in the ITU's Table of Frequency Allocations. These allocations may only apply to a group of countries.
See also: Radio spectrum, Electromagnetic spectrum