The IEC has developed and specified this test method to verify the standardized performance of a FAC, especially one that has been temporarily adapted from a SAC.

For radiated emission measurements in the 1 GHz to 18 GHz range, EMI test sites must be validated by measuring the SVSWR. This ratio compares the maximum received signal to the minimum received signal, which is influenced by interference from both the direct and reflected signals.

The SVSWR method is in line with CISPR 16-1-4. This requires special antennae described in the standard.
Site VSWR validations are performed from 1 GHz – 18 GHz