The Radio Spectrum for Beginners
The Radio Spectrum
I could never hope to fully describe the RF spectrum, but here are the more obvious large chunks. This page assumes you understand the basic prefixes:
1000 Hz = 1 kHz 1000 kHz = 1 MHz = 1,000,000 Hz 1000 MHz = 1 GHz = 1,000,000 kHz
You sometimes see the wavelength instead of the frequency.
The speed of light is
c = 300,000,000 meters/second
So, the wavelength in meters is 300 divided by the
frequency in MHz.
Higher frequency —> shorter wavelength
Lower frequency —> longer wavelength
Names were assigned to broad ranges of frequencies starting at the birth of radio. What was a very high frequency for the equipment of the 1920s is not very high at all. So the "short-wave" bands at (roughly) 3-30 MHz are, by today's standards, actually quite long waves! But we're stuck with the names — the terms commonly used are:
| Name | Frequency range | Propagation |
|
ELF Extremely Low Frequency |
3 – 30 kHz | Generally very poor, although at very high power levels it will penetrate salt water and earth |
|
VLF Very Low Frequency |
30 – 300 kHz | Generally worthless in day, longer range at night at higher frequencies. Much atmospheric noise. |
|
LF Low Frequency |
300 – 3000 kHz 0.3 – 3 MHz |
Absorbed by D layer of ionosphere during the day, continental coverage possible at night. |
|
HF High Frequency |
3 – 30 MHz | Refracts from F layers (F1 and F2) layers of ionosphere, world-wide coverage possible depending on frequency and ionospheric conditions (function of solar and geomagnetic activity) along the path. |
|
VHF Very High Frequency |
30 – 300 MHz |
Generally line of sight out to tens or hundreds
of kilometers. May be refracted by sporadic ionized clouds in E layer of ionosphere (called "sporadic-E" or "Es" propagation). Reflected by auroral curtains and ionized trails of meteorites. |
|
UHF Ultra High Frequency |
300 – 3000 MHz 0.3 – 3 GHz |
Generally line of sight out to tens of kilometers. Reflected by auroral curtains and ionized trails of meteorites. Absorption by atmospheric water by limited bands of frequencies starts at the upper end of this range (microwave ovens, at 2.4-2.5 GHz, use this phenomenon to heat food). |
Above about 1 GHz you tend to see "microwave" used as a general term.
ELF, VLF, and LF through the Medium-Wave Broadcast Band
Remember that these are just very rough listings, and in some cases they are U.S.-specific!
| Frequencies, kHz | Uses |
| 0.030 – 0.090 | US and Russian communications with submarines. Very low bandwidth (data rate), but these frequencies do propagate down into salt water. The U.S. system operates at 76 Hz, the Russian one at 82 Hz. |
| 10 – 60 | Long-range navigation signals, time signals |
| 150 – 175 | US DOD GWEN (Ground Wave Emergency Network) |
| 250 – 530 | Aviation navigation beacons |
| 530 – 1700 |
AM broadcast 10 kHz channel spacing in North America, 9 kHz worldwide |
The HF Bands — 1.7 - 30 MHz
The HF or "short-wave" bands, further divided into many uses:
1.800 - 2.000 Amateur 160m band 2.000 - 2.107 Maritime 2.107 - 2.170 Fixed 2.170 - 2.194 Maritime 2.197 - 2.300 Fixed 2.300 - 2.495 Broadcast 120m band 2.495 - 2.840 Fixed 2.840 - 3.155 Aeronautical 3.155 - 3.200 Fixed 3.200 - 3.400 Broadcast 90m band 3.400 - 3.500 Aeronautical 3.500 - 3.900 Amateur 80m band 3.900 - 4.000 Amateur 80m band+ Broadcast 75m band 4.000 - 4.438 Maritime 4.438 - 4.650 Fixed 4.650 - 4.750 Aeronautical 4.750 - 5.060 Broadcast 60m band 5.060 - 5.450 Fixed 5.450 - 5.730 Aeronautical 5.730 - 5.950 Fixed 5.950 - 6.200 Broadcast 49m band 6.200 - 6.525 Maritime 6.525 - 6.765 Aeronautical 6.765 - 7.000 Fixed 7.000 - 7.200 Amateur 40m band 7.200 - 7.300 Amateur 40m band+ Broadcast 41m band 7.300 - 7.450 Broadcast 41m band 7.450 - 8.100 Fixed 8.100 - 8.815 Maritime 8.815 - 9.040 Aeronautical 9.040 - 9.400 Fixed 9.400 - 9.900 Broadcast 31m band 9.900 - 9.995 Fixed 9.995 - 10.005 Time and frequency standards 10.005 - 10.100 Aeronautical 10.100 - 10.150 Amateur 30m band + Fixed 10.150 - 11.175 Fixed 11.175 - 11.400 Aeronautical 11.400 - 11.600 Fixed 11.600 - 12.100 Broadcast 25m band 12.100 - 12.230 Fixed 12.230 - 13.200 Maritime 13.200 - 13.360 Aeronautical 13.410 - 13.570 Fixed 13.570 - 13.870 Broadcast 22m band 13.870 - 14.000 Fixed 14.000 - 14.350 Amateur 20m band 14.350 - 14.990 Fixed 14.990 - 15.010 Time and frequency standards 15.010 - 15.100 Fixed 15.100 - 15.800 Broadcast 19m band 15.800 - 16.360 Fixed 16.360 - 17.410 Maritime 17.410 - 17.480 Fixed 17.480 - 17.900 Broadcast 16m band 17.900 - 18.030 Aeronautical 18.030 - 18.068 Fixed 18.068 - 18.168 Amateur 17m band 18.168 - 18.780 Fixed 18.780 - 18.900 Maritime 18.900 - 19.020 Broadcast 15m band 19.020 - 19.680 Fixed 19.680 - 19.800 Maritime 19.800 - 21.000 Fixed 21.000 - 21.450 Amateur 15m band 21.450 - 21.850 Broadcast 13m band 21.850 - 21.924 Fixed 21.924 - 22.000 Aeronautical 22.000 - 22.855 Maritime 22.855 - 23.200 Fixed 23.200 - 23.350 Aeronautical 23.350 - 24.890 Fixed 24.890 - 24.990 Amateur 12m band 24.990 - 25.670 25.670 - 26.100 Broadcast 12m band 26.100 - 26.175 Maritime 26.175 - 26.480 Land mobile 26.480 - 26.950 Government 26.950 - 27.410 "Citizen's band" 27.410 - 27.540 Land mobile 27.540 - 28.000 28.000 - 29.700 Amateur 10m band 29.700 - 29.800 Land mobile
VHF and UHF — 30 – 1000 MHz
| MHz | Use |
| 30 — 50 | "Low VHF" — longer-range VHF band used for two-way communications. construction companies, state police in US. |
| 50 — 54 | Amateur radio, 6m band. |
| 54 — 72 |
VHF television broadcast channels 2, 3, 4 There was originally a channel 1 at 48-54 MHz, but it was at a low enough frequency that at many times, especially in sporadic-E season during the summer months, the signals propagated too far. Broadcast stations on channel 1 would interfere with each other even at great distances. |
| 72 — 76 | Industrial control links, aviation marker beacons, radio astronomy. |
| 76 — 88 | VHF television broadcast channels 5 & 6. |
| 88 — 108 |
FM broadcast 200 kHz channel spacing in US: 88.1, 88.3, ... |
| 108 — 118 | Aviation navigation beacons. |
| 118 — 137 | Aviation communications. |
| 137 — 138 | Space to Earth. |
| 144 — 148 | Amateur radio, 2m band. |
| 148 — 152 | Satellites; Earth to space 148-150, satellite navigation 149.9-150.05. |
| 152 — 162 |
"High VHF" — shorter-range (kilometers to
tens of kilometers) two-way communications,
and pagers. Maritime mobile 157.0375-157.1875. |
| 162 — 174 | Government two-way communications, weather broadcasts (162-163 MHz), Lojack vehicle tracking/recovery. |
| 174 — 216 | VHF television broadcast channels 7-13. |
| 216 — 225 | Low-power health care, law enforcement tracking, maritime communications, radar, amateur radio (222-225 MHz). |
| 225 — 420 | Military aircraft and satellite links. |
| 420 — 450 | Amateur radio, 70cm band. |
| 450 — 470 | UHF two-way communications: business and government. |
| 470 — 698 | UHF television broadcast channels 14-51 |
| 698 — 806 | "D Block" band designated by the FCC for a national public safety broadband data network. |
| 764 — 869 |
APCO P25 (Association of Public-Safety Communication
Officials, Project 25) Public-safety two-way communications |
| 824 — 894 |
IS-54 / IS-139 (North American Digital Cellular),
digital mobile phones in North America, Asia, Australasia Handsets 824-849 MHz, base stations 869-894 MHz TDMA/FDM (Time-Domain Multiple Access / Frequency-Division Multiplexing) |
|
IS-95 (North American Digital Cellular),
digital mobile phones in North America, Asia, Australasia Handsets 824-849 MHz, base stations 869-894 MHz CDMA/FDM (Code-Division Multiple Access / Frequency-Division Multiplexing) |
|
|
AMPS (Advanced Mobile Phone Service),
old-style analog mobile telephones
in the Americas and elsewhere Handsets 824-849 MHz, base stations 869-894 MHz FDMA (Frequency-Division Multiple Access) Formerly US UHF television broadcast channels 73-83 |
|
| 860 — 949 |
TACS (Total Access Communications System),
analog mobile telephones in Africa and Asia ETACS: handsets 871-904 MHz, base stations 916-949 MHz NTACS: handsets 915-925 MHz, base stations 860-870 MHz FDMA (Frequency-Division Multiple Access) |
| 860 — 960 | RFID |
| 864 / 868 | CT2 (Cordless Telephone 2) digital cordless telephones |
| 880 — 960 |
GSM (Global System for Mobile Communications),
digital mobile telephones Handsets 880-915 MHz, base stations 925-960 MHz TDMA/FDM (Time-Domain Multiple Access / Frequency-Division Multiplexing) |
| 885 / 932 | CT1+ (Cordless Telephone 1) analog cordless telephones |
| 890 — 960 |
NMT (Nordic Mobile Telephone),
analog mobile telephones in Europe and Asia Handsets 890-915 MHz, base stations 935-960 MHz FDMA (Frequency-Division Multiple Access) |
| 898 / 915 / 2400 | ZigBee (IEEE 802.15.4) personal-area network |
| 902 — 928 | Radar, amateur radio 33cm band, industrial applications |
| 914 / 960 | CT1 (Cordless Telephone 1) analog cordless telephones |
| 944 / 948 | CT2+ (Cordless Telephone 2) digital cordless telephones |
Microwaves — 1 GHz and Up
1.030 GHz IFF / ATC radar beacon interrogate 1.090 IFF / ATC radar beacon reply 1.1176 GPS L5 signal 1.215 - 1.400 L-band radar 1.242 - 1.249 GLONASS navsats L1 freq (FDMA) 1.2276 GPS L2 freq (spread-spectrum, below thermal noise floor) 1.240 - 1.300 Amateur radio (calling freqs = 1296.1 SSB/CW, 1294.5 FM) 1.400 - 1.427 Protected radio astronomy band (1.420 is H20 resonance) 1.5754 GPS L1 freq (spread-spectrum, below thermal noise floor) 1.5445 SARSAT, search and rescue, EPRIB emergency beacons 1.535 - 1.542 Intelsat comsat 1.598 - 1.606 GLONASS navsats L2 freq (FDMA) 1.616 - 1.627 Iridium LEO satellite telephones 1.626 - 1.646 EPRIB emergency beacons 1.660 - 1.670 Protected radio astronomy band (hydroxyl resonance) 1.691 GOES wefax imagery 1.694 ESA Meteosat 1.700 - 1.900 SDS recon platforms 1.710 - 1.880 GSM-1800 digital mobile telephones 1.850 - 1.910 Personal Communications Services (PCS), mobile 1.850 - 1.990 GSM-1900 digital mobile telephones 1.880 - 1.900 DECT (Digital European Cordless Telephone) 1.895 - 1.918 PHS (Personal Handy Phone System, cordless phone) 1.930 - 1.990 Personal Communications Services (PCS), base 2.205 NASA downlink 2.206 SPOT recon platform 2.211 TDRS 2.2175 NASA downlink 2.250 NASA downlink 2.2875 NASA primary digital downlink 2.280 - 2.304 Early warning network 2.204 - 2.400 Deep space probes 2.300 - 2.550 S-band radar 2.300 - 2.310 Amateur radio (calling freqs = 2304.1 SSB/CW, 2305.2 FM) 2.320 - 2.345 DARS, Digital Audio Radio via Satellite, audio to automobiles 2.390 - 2.450 Amateur radio 2.402 - 2.484 Bluetooth data communication (FHSS) 2.410 - 2.484 802.11b, 802.11g wireless LAN (DSSS) 2.410 - 2.484 2.4 GHz cordless phones 2.450 Microwave ovens 2.450 - 2.500 ISM (Industrial, Scientific, Medical) 2.670 - 2.700 Protected radio astronomy band 2.700 - 3.700 S-band radar 2.840 H20 resonance SHF---------------------------------------------------------------------------- 3.300 - 3.500 Amateur radio 3.700 - 4.195 C-band satellite TV, channels 1-24 on (3720 + 20*(chan-1)) MHz 4.200 - 4.300 Radar altimeters 4.950 - 5.000 Protected radio astronomy band 5.031 - 5.091 MLS (microwave landing system) 5.150 - 5.350 802.11a wireless LAN 5.255 - 5.925 C-band radar (aviation WX radar at 5.4 GHz) 5.650 - 5.925 Amateur radio 5.725 - 5.825 802.11a wireless LAN (DSSS), 5.8 GHz cordless phones 5.725 - 5.875 ISM (Industrial, Scientific, Medical) 8.50 - 10.70 X-band radar (aviation WX 9.3 GHz, police 10.525 GHz) 10.00 - 10.50 Amateur radio (calling freq = 10.364 or 10.368) 10.45 - 10.60 X-band police radar 10.60 - 10.70 Protected radio astronomy band 10.90 - 11.75 Ku1-band satellite TV 11.75 - 12.50 Ku2-band satellite TV (11.7-12.2=Direct to Home, 12.2-12.7=DBS) 12.50 - 12.75 Ku3-band satellite TV (DBS) 13.40 - 14.40 Ku-band radar 15.35 - 15.40 Protected radio astronomy band 15.70 - 17.70 Ku-band radar 18.00 - 20.00 Ka-band satellite TV, North American channels 1-16 18.80 - 20.20 Iridium gateway downlinks 22.21 - 22.26 Protected radio astronomy band 23.00 - 24.25 K-band radar (police radar on 24.150 GHz) 24.00 - 24.25 Amateur radio (calling freq = 24.192 GHz) 24.00 - 24.25 ISM (Industrial, Scientific, Medical) 27.50 - 30.00 Iridium gateway uplinks EHF---------------------------------------------------------------------------- 33.40 - 36.00 Ka-band police radar 47.00 - 47.20 Amateur radio (SSB/CW calling freq = 47.040 GHz) 75.50 - 81.00 Amateur radio (SSB/CW calling freq = 80.640 GHz) 119.98 -120.02 Amateur radio (SSB/CW calling freq = 120.00 GHz) 142.00 -149.00 Amateur radio (SSB/CW calling freq = 144.00 GHz) 241.00 -250.00 Amateur radio (SSB/CW calling freq = 247.76 GHz)
Also see the frequency lists of UHF and microwave satellites at uhf-satcom.com.
Satellite Navigation
| System | Signal | Freq. MHz | BW MHz |
| GPS | L1 | 1575.42 | 15.345 |
| L2 | 1227.6 | 11 | |
| L5 | 1176.45 | 12.45 | |
| QZSS | L1 | 1575.42 | 12 |
| L2C | 1227.6 | 11 | |
| L5 | 1176.45 | 24 | |
| E6/LEX | 1278.75 | 20 | |
| GLONASS I | L1 | 1602 | 6.5 |
| L2 | 1246 | 5 | |
| GLONASS II | L1 | 1575.42 | 6.5 |
| L1 | 1600.995 | 15.365 | |
| L2 | 1248.06 | 8.75 | |
| L3 | 1202.025 | 20.46 | |
| L5 | 1176.45 | 10.22 | |
| Galileo | E1 | 1575.42 | 12 |
| E5a | 1176.45 | 12.5 | |
| E5b | 1207.14 | 12.5 | |
| E6 | 1278.75 | 20 | |
| COMPASS CPII / Beidou | E2 | 1561.098 | 16 |
| E5 | 1207.14 | 16 | |
| E6 | 1268.52 | 16 | |
| B1 | 1561.098 | 4.092 | |
| COMPASS CPIII / Beidou | B1-2 | 1589.74 | 4.092 |
| B2 | 1207.14 | 24 | |
| B3 | 1268.52 | 24 | |
| B1-BOC | 1575.42 | 16.368 | |
| B2-BOC | 1207.14 | 5.115 | |
| B3-BOC | 1268.52 | 35.805 | |
| L5 | 1176.45 | 24 | |
| IRNSS-1 | L5 | 1176.45 | 4.092 |
| IRNSS-2 | S-band | 2492.028 | 16.5 |
Then there are the microwave band designations:
| Frequency Range | Microwave / Radar Band Designation |
| 216 – 450 MHz | P Band |
| 1 – 2 GHz | L Band |
| 216 – 450 MHz | P Band |
| 1 – 2 GHz | L Band |
| 2 – 4 GHz | S Band |
| 4 – 8 GHz | C Band |
| 8 – 12 GHz | X Band |
| 12 – 18 GHz | Ku Band |
| 18 – 26.5 GHz | K Band |
| 26.5 – 40 GHz | Ka Band |
| 30 – 50 GHz | Q Band |
| 40 – 60 GHz | U Band |
| 50 – 75 GHz | V Band |
| 60 – 90 GHz | E Band |
| 75 – 110 GHz | W Band |
| 90 – 140 GHz | F Band |
| 110 – 170 GHz | D Band |
| 110 – 300 GHz | mm Band |