A time-domain method for characterizing the reflection coefficient of absorbing materials from 30 to 1000 MHz

Electromagnetic Ferrite Tile Absorber

“…Although an arch 0.0E+0 4.0E-9 8.0E-9 1. antennas (typically from 1 to 4 m from the antenna apfrequency methods to measure reflectivity at arbitrary angles ertures). and polarization (54)(55)(56).…”

“…More sample response plus a component that emanates from detailed descriptions of time-and frequency-domain versions the shadow region behind the sample. This process removes significant systematic effects due to antenna-toof this measurement system are given in (54)(55)(56)(57)(58). A rectanguantenna coupling and spurious environmental refleclar ferrite-tile sample (or metal plate reference) is placed in tions.…”

Measurement uncertainty of radiated emissions

“…The primary source of measurement uncertainty due to the anechoic chambers is wall reflections (single or multiple). Absorber design and the ability to analyze [29] and to measure [30,31] absorber reflectivity are improving, but it is still difficult to evaluate measurement uncertainty in anechoic chambers. A recent paper [32] showed agreement between measured and theoretical site attenuation within 4 dB at frequencies from 35 to 1000 MHz, but poorer agreement at 30 MHz.…”

On the use of the multifrequency method for studying scattered fields during the antenna measurements in an anechoic chamber

“…Development and operation of AEC require the anechoity quality control. Anechoic chambers and radar absorbing materials can be certified by different methods [1,[3][4][5][6] allowing one to determine the sources and levels of reflections and reach low scattering levels thereby ensuring measurements of antenna characteristics with a sufficiently high accuracy. However, the AEC certification methods are not intended for revealing the scattered signals during the measurement of antenna characteristics.…”