Equivalent Isotropically Radiated Power (Eirp) - Honeywell OneWireless XYR 6000 Professional Installation Manual

7. Equivalent Isotropically Radiated Power (EIRP)

6.1. Antenna Details
7. Equivalent Isotropically Radiated Power (EIRP)
In radio communication systems, Equivalent Isotropically Radiated Power (EIRP) or, alternatively,
Effective Isotropic Radiated Power, is the amount of power that would have to be emitted by an isotropic
antenna (that evenly distributes power in all directions and is a theoretical construct) to produce the peak
power density observed in the direction of maximum antenna gain. EIRP can take into account the losses
in transmission line and connectors and includes the gain of the antenna. The EIRP is often stated in terms
of decibels over a reference power level that would be the power emitted by an isotropic radiator with an
equivalent signal strength. The EIRP allows making comparisons between different emitters regardless of
type, size or form. From the EIRP, and with knowledge of a real antenna's gain, it is possible to calculate
real power and field strength values.
EIRP(dBm) = Radio TX Power (dBm) – Cable Loss (dB) + Antenna Gain(dBi)
Antenna gain is expressed relative to a (theoretical) isotropic reference antenna (dBi).
18 OneWireless XYR 6000 Transmitter Professional Installation Guide Revision 3
September 2012