The Radio Spectrum for Beginners

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 areas they are U.S.-specific!

Frequencies Uses
30 — 90 Hz US and Russian communications with submarines. Very low bandwidth (data rate), but these frequencies do propagate down into salt water.
10 — 60 kHz Long-range navigation signals, time signals
150 — 175 kHz US DOD GWEN (Ground Wave Emergency Network)
250 — 530 kHz Aviation navigation beacons
530 — 1700 kHz
0.530 — 1.700 MHz
AM broadcast
10 kHz channel spacing in US, 9 kHz worldwide

The HF Bands — 1.7 - 30 MHz

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

30 — 50 MHz "Low VHF" — longer-range VHF band used for two-way communications. Construction companies, state police in US.
50 — 54 MHz Amateur radio, 6m band.
54 — 72 MHz 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 MHz Industrial control links, aviation marker beacons, radio astronomy
76 — 88 MHz VHF television broadcast channels 5 & 6
88 — 108 MHz FM broadcast
200 kHz channel spacing in US: 88.1, 88.3, ...
108 — 144 MHz Aviation — generally, navigation beacons at the low end and communication at the high end
Some satellites 136—144 MHz
144 — 148 MHz Amateur radio, 2m band
148 — 152 MHz Satellites
152 — 162 MHz "High VHF" — shorter-range (kilometers to tens of kilometers) two-way communications, and pagers
162 — 174 MHz Government two-way communications, weather broadcasts (162-163 MHz), Lojack vehicle tracking/recovery
174 — 216 MHz VHF television broadcast channels 7-13
216 — 225 MHz Low-power health care, law enforcement tracking, maritime communications, radar, amateur radio (222-225 MHz).
225 — 420 MHz Military aircraft and satellite links
420 — 450 MHz Amateur radio, 70cm band
450 — 470 MHz UHF two-way communications: business and government
470 — 698 MHz UHF television broadcast channels 14-51
698 — 806 MHz "D Block" band designated by the FCC for a national public safety broadband data network.
764 — 869 MHz APCO P25 (Association of Public-Safety Communication Officials, Project 25)
Public-safety two-way communications
824 — 894 MHz 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 MHz 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 MHz RFID
864 / 868 MHz CT2 (Cordless Telephone 2) digital cordless telephones
880 — 960 MHz 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 MHz CT1+ (Cordless Telephone 1) analog cordless telephones
890 — 960 MHz 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 MHz ZigBee (IEEE 802.15.4) personal-area network
902 — 928 MHz Radar, amateur radio 33cm band, industrial applications
914 / 960 MHz CT1 (Cordless Telephone 1) analog cordless telephones
944 / 948 MHz 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
  1.215 - 1.400	L-band radar
  1.224 - 1.270	GLONASS navsats
  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
  1.603 - 1.636	GLONASS navsats
  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 http://www.uhf-satcom.com/

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

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