13-centimeter band
A UHF microwave band for amateur radio and satellite use.
The 13-centimeter band (also called the 2.3 GHz or 2.4 GHz band) sits within the UHF microwave portion of the radio spectrum, specifically inside the S-band, and is allocated internationally to amateur radio and amateur satellite use on a secondary basis. The amateur radio segment runs from 2300 MHz to 2450 MHz, while the amateur satellite segment is limited to 2400 MHz to 2450 MHz, with satellite operations required to operate on a non-interference basis to other users (per ITU footnote 5.282). Amateur licensees may use a wide variety of modes for telecommunication within these ranges, and the allocations are identical across all three ITU Regions.
The 2300–2400 MHz range is also allocated to the Mobile service on a primary basis, which leads to difficult sharing scenarios and inconsistent amateur allocations at the national level. Above 2400 MHz, the band overlaps with the 2.4 GHz ISM (industrial, scientific, and medical) band. Amateur stations must accept harmful interference from ISM equipment like microwave ovens, while unlicensed devices such as Wi-Fi and Bluetooth must not cause interference to amateur stations.
In 2009, amateur radio operators achieved the first Earth-Venus-Earth contact using the 13 cm band. Within HAMNET, this band is mainly used for user access.
Key frequency allocations include 2,304.1 MHz as the Region 2 CW and SSB calling frequency, 2,320.2 MHz as the Region 1 narrow-band calling frequency, and 2,450 MHz as the operating frequency of ISM devices. While amateur radio is generally permitted worldwide from 2300 to 2450 MHz, national regulations vary. In Germany, only frequencies above 2320 MHz are allocated to amateurs. In the United States, the 13 cm band consists of two segments: 2.300 to 2.310 GHz and 2.390 to 2.450 GHz. The segment from 2.310 to 2.390 GHz was withdrawn from amateur service and reassigned to direct satellite radio broadcasting (e.g., Sirius XM Radio). Within the U.S., the 2.390 to 2.417 GHz portion is allocated to amateur radio on a primary basis, while the rest of the band is secondary. It is authorized to any amateur licensee holding a Technician or higher class license in the U.S., or a Basic or higher license in Canada.
- Frequency range
- 2300 MHz to 2450 MHz
- Amateur satellite subband
- 2400 MHz to 2450 MHz
- Region 2 cw ssb calling frequency
- 2304.1 MHz
- Region 1 narrow band calling frequency
- 2320.2 MHz
- Ism device operating frequency
- 2450 MHz
- First earth venus earth contact year
- 2009
Lore & Background
The 13-centimeter band is allocated internationally to amateur radio and amateur satellite services on a secondary basis, with the amateur satellite subband restricted to 2400–2450 MHz and subject to non-interference conditions per ITU footnote 5.282. The band overlaps with the 2.4 GHz ISM band above 2400 MHz, meaning amateur stations must accept harmful interference from ISM equipment such as microwave ovens, while unlicensed devices like Wi-Fi and Bluetooth must not cause interference to amateur stations. National allocations vary: in Germany, only frequencies above 2320 MHz are allocated; in the United States, the band comprises two segments (2.300–2.310 GHz and 2.390–2.450 GHz), with the 2.310–2.390 GHz segment withdrawn for direct satellite radio broadcasting. The segment 2.390–2.417 GHz is primary in the US, while the remainder is secondary. US amateurs must hold a Technician or higher license, and Canadian amateurs a Basic or higher license.
Reader's Guide
The 13-centimeter band's significance lies in its role as a microwave allocation for amateur radio and satellite experimentation, despite sharing challenges with primary mobile services in the 2300–2400 MHz range and ISM devices above 2400 MHz. The band's history includes the first Earth-Venus-Earth contact by amateurs in 2009, highlighting its use for deep-space communication experiments. In HAMNET, the band is primarily used for user access. The bandplan published by the American Radio Relay League recommends frequencies based on intended activity, and the band supports a wide variety of modes. Its legacy is shaped by national variations—such as the US losing a segment to satellite radio—and the requirement that amateurs accept interference from ISM equipment, reflecting the secondary status of the allocation. The band remains a venue for high-speed multimedia radio and other advanced telecommunications, as noted in related references.
Did You Know?
- The first Earth-Venus-Earth contact by amateur radio operators was established on the 13 cm band in 2009.
- The amateur satellite subband is 2400–2450 MHz, used on a non-interference basis to other radio users.
More in Amateur Radio, Part 3 1-24
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