EIRP Calculator
Calculate Effective Isotropic Radiated Power for RF systems
EIRP (Effective Isotropic Radiated Power) is calculated using the formula:
- EIRP = Pt × G × L
- Pt = Transmitter power in watts
- G = Antenna gain (linear, not dB)
- L = Cable loss factor (linear, not dB)
- For dB calculations:
- EIRP (dBW) = Pt (dBW) + G (dBi) - L (dB)
- EIRP (dBm) = EIRP (dBW) + 30
This calculator handles all necessary conversions between linear and logarithmic units automatically.
Common Units:
- Watts (W): Linear power unit, used for absolute power levels
- dBW: Decibels relative to 1 watt
- dBm: Decibels relative to 1 milliwatt
- dBi: Antenna gain relative to an isotropic radiator
Key Conversions:
- dBW = 10 × log₁₀(watts)
- dBm = dBW + 30
- Linear gain = 10^(dB gain ÷ 10)
EIRP calculations are essential for:
- Regulatory compliance in RF transmissions
- Satellite communications link budgets
- Wireless network planning
- Broadcasting system design
- RF coverage prediction
- EMC/EMI assessments
Why is EIRP important?
EIRP is crucial for regulatory compliance, system performance evaluation, and comparing different RF systems on an equal basis. It helps ensure transmitters operate within legal limits and achieve desired coverage.
What is the difference between ERP and EIRP?
EIRP is referenced to an isotropic antenna (theoretical perfect sphere of radiation), while ERP is referenced to a dipole antenna. EIRP is 2.15 dB higher than ERP.
Why use decibel units?
Decibels (dB) make it easier to work with very large or small numbers and simplify calculations by turning multiplication and division into addition and subtraction.