An improved design for indoor ranges

A new design for high performance anechoic chambers has been developed which offers a wider test region and significantly lower levels of reflected energy. A chamber of this design is in the shape of a pyramidal horn that tapers from a small illuminating end to a large rectangular test region as shown in Fig. 1. With this geometry, the usual specular reflections from chamber walls are avoided. Higher measurement accuracies for both radar cross section and antenna parameters have been verified in a 90 foot long "tapered" chamber, recently installed by The B. F. Goodrich Company for The Bunker-Ramo Corporation at Canoga Park, Calif.