Anti-fading polygonal cylinder passive repeater

A method for controlling the phase distribution of the radiation field of an aperture type antenna is discussed and it is shown that this method is best suited to prevent fading. The method modifies the shape of a conventional flat reflector excited by plane waves into a polygonal cylinder which inscribes a shallow parabolic cylinder, so that a near-axis directional beam is formed even in the direction of the first null point of the reflected waves. The intensity level at the first null point of a polygonal cylinder reflector designed to keep the gain reduction below about 1 dB directly on the axis agrees well with the predicted mean field intensity due to fading at a receiving point. The use of a polygonal cylinder is economical, since a flat reflector can easily be readjusted into the proposed type.