3 Radio Transmission

As an introduction, the most important frequency ranges and applications as well as some antennas are shown. Some examples for frequency ranges are given in Table 3-2 and corresponding antennas are given in Tab. 3-1.

Tab. 3-1: Technical use of wave and frequency ranges.

Wave length λ	Frequency ƒ	Name	Typical antennas	Typical applications, frequency ranges, bitrates
c=λ·ƒ	c=λ·ƒ
	8 Hz	Schumann resonance
10000 km 1000 km 100 km	30 Hz 300 Hz 3 kHz			Analog voice transmission, analog telephony (300Hz 3.4 kHz), HiFi (20 Hz - 20 kHz)
10 km	30 kHz	VLF Very Low Frequency LF Low Frequency		Symetrical and coaxial lines ( long distance); PCM (64 kBit/s to 564, 992 Mbit/s); radio-navigation, LF broadcast (150 - 285 kHz AM)
1 km	300 kHz
		MF Medium Frequency	Ferrite frame	MF broadcast (535 - 1605 kHz AM)
100 m	3 MHz
		HF High Frequency	Dipole curtain, corner reflector, Log-periodical antenna	Amateur radio; maritime radio; HF broadcast (6 - 21,45 MHz AM)
10 m	30 MHz
1 m	300 MHz	VHF Very High Frequency UHF Ultra High Frequency	Dipole field, Log-periodical coil, λ/4-vertical ring, folded dipole, Yagi	Voice Radio, VHF broadcast (87.5 - 108 MHz FM), TV bands (I: 48 - 68 MHz, III: 175 - 223 MHz); cable-TV (47 - 450 MHz) TV Band IV/V (471 - 789 MHz); mobile communication (GSM 890 - 960 MHz  u. 1760 -  1870 MHz, UMTS); DECT, digital broadcast (DAB, DVB-T); MMDS (2.5 - 2.69 GHz)
10 cm	3 GHz
1 cm	30 GHz	SHF Super High Frequency (centimeter waves) EHF Extremly High Frequency (millimeter waves)	Parabolic antennas, lenses, dielectrical slot antenna, horn antenna, micro strip antenna	mobile communication (HIPERLAN); directional radio, radar; automotive radar (24 GHz); satellite radio (6/4 GHz, 14/11 GHz, 30/20 GHz) LMDS (26.5 - 28.5, 40.5 - 42.5 GHz); WLAN; MBS (58 - 62 GHz); car radar (76 - 77 GHz)
1 mm	300 GHz

Electromagnetic waves cover the spectrum up to the frequency of 10²⁴ Hz. This broad range is divided in sub-band based on the different physical properties. The limits in Tab. 3-1 are approximations as the frequency ranges partly overlap. In Tab. 3-1, frequencies are shown up to 300·10⁹ Hz as these frequencies are in use in communications nowadays. Commercial use mostly takes place in frequencies below 100 GHz. An exception is optical communication in the range of 0.8 μm to 1.6 μm (above 1 THz). The microwave range (above 1 GHz) has large bandwidth, therefore it is further divided sub-bands marked by letters.

The use of frequencies for radio communications follows international standards by the International Telecommunication Union (ITU), a subdivision of the United Nations (UN) located in Geneva. The official specification is called „Radio Regulations“. The national regulation authority in Germany responsible for the implementation based on the law for telecommunications is the “Bundesnetzagentur”. First there is a plan for frequency allocation which shows which service is the primary or secondary user in the corresponding frequency range. To set up a service the Bundesnetzagentur needs to assign the frequency to the service provider.

Tab. 3-2: Frequency spectrum and some applications.

Frequency (above the given value)	Name	Major Applications
3 THz	Visible light Infrared light	Light communication systems (access networks)
300 GHz	Sub-millimeter waves Visible light
30 GHz	EHF extremely high	Central disaster prevention radio Communication networks Simple radio communications (Automotive sensors; point-to-point and point-to-multipoint radio as MMDS, MVDS, LMDS)
3 GHz	SHF super high	Satellite communications and satellite broadcasting Microwave relay Various radar
300 MHz	UHF ultra high	Television broadcasting Land mobile communication Personal radios Maritime satellite communications (GSM to LTE, HIPERLAN, Wi-Fi, DECT; cable TV; DVB-T)
30 MHz	VHF very high	FM radio broadcasting Television broadcasting Aeronautical radio Pocket pager
3 MHz	HF high	Short wave broadcasting Ship communications Aeronautical radio
300 kHz	MF medium	AM radio Ship communications
0 Hz	LF low VLF very low	Air traffic beacons