This spreadsheet allows comparison between field strengths at a given distance (commonly specified in the USA) and the radiated power of a transmitter (commonly specified in Europe). Please note that there is a difference between ERP (radiated power from a transmitter using a dipole antenna) and EIRP (radiated power using an isotropic, or "perfect" antenna). USA regulations will commonly use EIRP while European regulations use EIRP above 1ghz and ERP below 1ghz. | Field Strength vs Radiated Power | Note: FS = Field Strength, defined at a distance from the antenna | EIRP | ERP | FS @ 3m | FS @ 10m | | (mw) | (mw) | (mV) | (mV) | | 1 | 0.6 | 58 | 17 | | 3 | 1.8 | 100 | 30 | | 10 | 6 | 183 | 55 | | 30 | 18 | 317 | 95 | | 100 | 60 | 577 | 173 | | 302 | 182 | 1000 | 301 | | 1000 | 600 | 1800 | 548 | | 3000 | 1800 | 3200 | 1000 | | | | | | | | |
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Note: Data courtesy of Great Circle Design and LPRA | 
