R-CARD FENCES AS AN EDGE TREATMENT FOR COMPACT RANGE REFLECTORS

摘要

Compact range reflector edge diffraction can be reduced by placing a well-designed R-card fence in front of the reflector edges. The impact of this fence can be expressed mainly in terms of its ability to attenuate transmitted energy through the R-card. Thus, the resistance of the R-card is synthesized to satisfy a chosen GO aperture taper. A Kaiser-Bessel taper produces an ideal taper transition and hence a large target zone at the lowest operating frequency. Since a proper design requires that the R-card be located near the curved reflector edge, multi flat R-card segments are designed and assembled around the periphery of the reflector. The R-cards then attenuate the transmitted edge diffracted field and direct the reflected signal away from the test zone onto the anechoic chamber walls, which results in a significant improvement in the uniformity of the test zone fields.