ANSI C63.5-2001 pdf download Draft Standard – American National Standard for Electromagnetic Compatibility— Radiated Emission Measurements in Electromagnetic Interference (EMI) Control—Calibration of Antennas (9 kHz to 40 GHz)
3.0 Definitions The following definitions apply specifically to the subject treated in this standard. For additional definitions, see ANSI C63.14-1992 and IEEE Std 100-1996.
3.1 ambient level: The magnitude of radiated and conducted signals and noise existing at a specific test location in the absence of signals from a test sample.
3.2 antenna factor: Ratio of the electric field in the polarization direction of the antenna to the voltage induced across the load connected to the antenna and expressed in decibel form (20 log (E/V o ).
3.3 free-space antenna factor: Antenna factor that is not influenced by adjacent objects (in dB).
3.4 Geometry Specific Correction Factors (GSCF): Correction factors (in dB) that are calculated or measured for each specific geometry and that are added to the site-attenuation that has been calculated using the theoretical model that employs near free-space or free space antenna factors. These correction factors include the effect of the 1/r 2 and 1/r 3 radiation terms, non-uniform illumination of the receive antenna, mutual coupling between the transmitting and receiving antennas, and mutual coupling between the antennas and the ground plane.
3.5 near free-space antenna factors: Antenna factors (in dB) that are minimally affected by the test environment. The test setup for this condition is R=10 m, h 1 =2 m, and h 2 =1 to 4 m. This value will represent the free-space antenna factor within an error smaller than the measurement uncertainty. This error is negligible when these antenna factors are used for product emission measurements.
3.6 ground plane: A conducting surface or plate used as a common reference point for circuit returns and electric or signal potentials.
3.7 ideal site: A test site on which the reflective surface is flat, level and has infinite conductivity and size.
3.8 measurement geometry: A specified polarization, separation distance, transmitting height, and receiving height(s) for a pair of antennas during their antenna factor measurement.
3.9 normalized site attenuation (NSA): Site attenuation divided by the free-space antenna factors of the transmitting and receiving antennas (all in linear units). Results can be stated in decibel units.
3.10 radiated emissions test site: A site with specified requirements suitable for measuring radio interference fields radiated by a device, equipment, or system under test.