Effective radiation power

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The effective radiated power (also effectively radiated power ; English effective radiated power , ERP or also erp ) is a computational variable which, in the field of antenna technology, expresses the power fed into a transmitting antenna multiplied by its antenna gain . The power value determined in this way does not occur physically with antennas with directional effect - it would only occur if the respective non-directional reference antennas were used as the antenna. For antennas with directional effect and if no direction is specified explicitly, the main beam direction of the transmitting antenna is assumed. The antenna gain is maximum in this direction. Depending on the reference antenna used, a distinction is made between the two terms ERP and EIRP.

ERP

With ERP, the half-wave dipole (λ / 2) is used as the reference antenna for the antenna gain , the wavelength is expressed with the Greek letter λ . In order to identify the reference antenna for antenna gain, this is usually given in dBd, with the “d” appended to the unit dB standing for the reference antenna “dipole”, more precisely the half-wave dipole.

  • ... power fed into the antenna (in watts )
  • ... antenna gain compared to a half-wave dipole (dimensionless)

EIRP

If one relates the antenna gain to the isotropic radiator , one speaks of EIRP, English equivalent isotropic radiated power . Since ERP and EIRP only differ in the reference antenna for the antenna gain (a half-wave dipole has an antenna gain of 1.64 compared to an isotropic radiator, corresponding to 2.15 dBi), the following relationship exists:

Spellings

ERP is often treated as a physical quantity , even if this value does not physically occur in an antenna with directional effect. A unit (watt) is assigned to the calculated variable. Another possibility is to put ERP in brackets after the unit of measure , e.g. B. Watt (ERP) . Often the transmission characteristics are also given, abbreviated as D stands for directional ( Directed ) and ND for non-directional ( Non-Directed ).

Individual evidence

  1. ↑ ITU, Radio Regulations, ARTICLE 1 Terms and definitions, Section VI - Characteristics of emissions and radio equipment, 1.162: effective radiated power (erp) (in a given direction): The product of the power supplied to the antenna and its gain relative to a half-wave dipole in a given direction. | Effective Radiated Power (ERP) (in a given direction): Product of the power supplied to the antenna and its gain in relation to a half-wave dipole in a given direction.
  2. ↑ ITU: final acts of the European Broadcasting Conference in the VHF and UHF bands Stockholm, 1961, Annex 2 to the REGIONAL AGREEMENT for the EUROPEAN BROADCASTING AREA, Chapter 5: Effective Radiated Power (ERP) The term "Effective Radiated Power" is defined in No. 98 of the Radio Regulations. For sound transmissions this is the unmodulated carrier power; for vision transmissions it is the peak envelope power.
  3. ^ ITU, final acts of the Regional Administrative Conference for the Planning of VHF Sound Broadcasting (Region 1 and Part of Region 3) Geneva, 1984
  4. ^ Hans Heinrich Meinke , Friedrich-Wilhelm Gundlach : Pocket book of high frequency technology , 4th edition 1985, Springer-Verlag, page A2
  5. ↑ Geng, Wiesbeck, Planning Methods for Mobile Communication , 1998, Springer Verlag, Chapter 2.3.3
  6. ^ ITU, Recommendation ITU-R V.574-4: USE OF THE DECIBEL AND THE NEPER IN TELECOMMUNICATIONS
  7. ↑ ITU, Recommendation ITU-R BS.1195: TRANSMITTING ANTENNA CHARACTERISTICS AT VHF AND UHF
  8. ↑ http://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/OfflicheNetze/Rundfunk/Antrag_UKW_Frequenzzutteilung_pdf.pdf