Side wall diffraction & optimal back wall design in elongated chambers for far–field antenna measurements at VHF/UHF frequencies

The side wall diffraction has been studied in elongated rectangular and tapered anechoic chambers at VHF/UHF bands. Methods for diffraction reduction were suggested. The concept of side wall diffraction is examined and trade-offs are identified. Optimal back wall design methods are suggested. It is shown that reflectivity improvement of greater than 10 dB can be effectively achieved with a pyramidal shape absorptive back wall, thus extending the chamber operation to lower frequencies.