Phase efficiency of the reflective array antenna

A reflective array consists of a large number of passive phase shifting elements placed on a plane or a conformal surface. Each element provides a total reflection to an incident wave with a certain phase shift. By choosing the phase shift of each element properly, the energy of an incident plane wave can be focused into a feedhorn placed in front of the array, thus producing a reflector antenna. A systematic theory on the phase efficiency of planar reflective array antennas is given and two kinds of arrays with element phase shifting values chosen from a continuous or quantised range are studied. The relationship between the phase efficiency, element size and the focal-length-to-diameter ratio is discussed. The influences of phase quantisation error and the manufacturing and installation tolerance on the phase efficiency are analysed using probability theory. A new reflective phase correcting array with multilayer dielectric tiles is presented. Experimental results agree well with the theoretical predictions