Deep Dive into ERP/EIRP Calculations

Introduction

This guide explains how to calculate Effective Radiated Power (ERP) and Effective Isotropic Radiated Power (EIRP).

What are ERP and EIRP?

  • ERP (Effective Radiated Power):
    The amount of power that an antenna radiates, taking into account the antenna gain and cable loss.

  • EIRP (Effective Isotropic Radiated Power):
    The amount of power that an antenna would radiate if it were an isotropic antenna (an antenna that radiates power equally in all directions).

Formulas for ERP and EIRP

  • EIRP (dBm) = Transmitter Power (dBm) + Antenna Gain (dBi) - Cable Loss (dB)
  • ERP (dBm) = Transmitter Power (dBm) + Antenna Gain (dBd) - Cable Loss (dB)
  • ERP (W) = EIRP (W) / 1.64

How to Calculate ERP and EIRP

  1. Determine the transmitter power in dBm or Watts.
  2. Determine the antenna gain in dBi or dBd.
  3. Determine the cable loss in dB.
  4. Use the formulas above to calculate ERP and EIRP.

Why are ERP and EIRP Important?

  • They are used to determine the maximum power that a transmitter can radiate.
  • They are used to ensure that transmitters comply with regulatory limits.

Understand ERP/EIRP calculations with this guide!

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