Whitepaper
Selecting the Right EMI Antenna
This application note from Com-Power provides a practical guide to choosing the correct antenna for radiated EMI emissions and immunity testing. It covers the major antenna types used in EMC work — monopole, dipole, biconical, log-periodic, biconical-log (CombiLog), horn, and loop — describing the frequency range, physical characteristics, and typical application context for each. The document explains antenna factor, how it varies with frequency, and how it fits into the E-field calculation alongside coax loss, preamplifier gain, and attenuator loss. It includes worked examples for calculating compliance limits at non-standard test distances and covers typical test setups for consumer, commercial, automotive, and military/aerospace testing under standards such as CISPR 11/32, CISPR 25, and MIL-STD-461. Brief guidance on antenna calibration methods is provided at the close.