Reflective Array Antenna

Abstract

In addition to various Fresnel zoneplate antennas, there is another type of electrically large antennas hased on the principle of phase correction — the passive phase correcting array antenna, which consists of a regular array (Cartesian array, for instance) of phase shifting elements over a plane and a feed. In contrast to the normal array antenna which requires a feeding network, the elements in a phase correcting array are excited by the radiation field of the feed and the array radiation pattern is controlled by adjusting the phase shift or the surface impedance of each element in the array [47–50]. This type of antennas possesses the versatility of the conventional array antenna in that a variety of radiation patterns can be produced by changing the distribution of the phase correcting function across the antenna aperture. In principle, there are both reflective and transmissive arrays. This chapter is devoted to reflective arrays only, though the principle applies equally to transmissive arrays.