Antenna factor and field strength converter
Convert between receiver voltage (dBµV) and radiated field strength (dBµV/m) using the antenna factor (AF).
Formulas
E (dBµV/m) = V (dBµV) + AF (dB/m)
AF = 20·log₁₀(f_MHz) − 20·log₁₀(G) − 29.77
Engineering background
The antenna factor AF converts incident field strength into receiver port voltage. In EMC radiated-emission measurements, receiver reading plus AF and amplifier gain yields the free-space electric field.
Key benefits
Enter receiver voltage and antenna factor to instantly get the field strength.
Formula matches the EMC radiated-emission measurement workflow for quick on-site checks.
Suited to radiated-emission (RE) test data post-processing.
How to use
- 1 Enter the receiver port voltage V (dBµV).
- 2 Enter the antenna factor AF (dB/m, from the antenna calibration certificate).
- 3 Read the field strength E (dBµV/m).
Use cases
- › Radiated-emission (RE) testing: convert receiver readings to field strength and compare with limits.
- › Antenna calibration verification.
- › Field-strength calculation in EMC reports.
FAQ
Where does the antenna factor AF come from?
The antenna calibration certificate lists AF (dB/m) per frequency.
Should preamplifier gain be included?
Yes. Final E = V + AF + preamplifier gain (dB). This tool computes V + AF; add the amplifier gain separately.