Abstract:
A dual-chambered anechoic chamber used in conjunction with spatial averaging for making transmission measurements of electromagnetic devices. The anechoic chamber includes a first tapered chamber with a first aperture, a second tapered chamber with a second aperture opposed to the first aperture, an alignment apparatus for aligning the two chambers and, if necessary, for positioning a test device between the apertures, and a positioning mechanism for mounting and determining the position of a transmitter antenna. A receiver antenna in the second chamber receives test signals transmitted from the transmitter antenna. At selected transmitter antenna positions, measurements are taken at different frequencies. For each transmitter position, a measurement is made with the test device positioned between the apertures, and another without the test device. When all desired measurements have been made, the measurement data are spatially averaged; i. e.