Power budget: ERP and EIRP
Transmitter power, cable and antenna gain give you EIRP and ERP. The cable loss calculator gives you the loss per 100 m.
Power budget
What's left of the transmit power after cable and antenna. Take the loss from the cable loss calculator or from your datasheet.
How the page calculates
- Cable loss in dB = attenuation per 100 m / 100 · length
- P at the antenna = P · 10^(−loss / 10)
- EIRP = P at the antenna · 10^(gain in dBi / 10)
- dBi = dBd + 2.15
- ERP = EIRP / 1.64
EIRP refers the radiation to an isotropic radiator, ERP to a half-wave dipole; that's why ERP is a factor of 1.64 (2.15 dB) below EIRP. Depending on the band, the limits in the German regulations apply to PEP at the transmitter output or to ERP; the band plan shows it for each band.
Related terms
- PEP
- peak envelope power, the way the limits are stated
- ERP and EIRP
- radiated power, referred to a dipole or to an isotropic radiator
- dBd and dBi
- antenna gain referred to a dipole or isotropic radiator, difference 2.15 dB