scanning reflective antennas
Recently the big attention to research of characteristics of reflective arrays with electronic scanning of a beam is paid. The most traditional way of maintenance of phase shift in elements reflectarrays, are phase shifting the short-circuited pieces of transmission lines commutated by pin-diodes (reflective phase shifters). Commutators on the basis of microelectromechanical and nanoelectromechanical systems (MEMS and NEMS), built in radiating structure are even more often used for this purpose. As, the phase shifters using semiconductor devices with variable capacity, operated voltage are applied, ferrite phase shifting sections etc. For a cent metric and mill metric wave band the specified approaches lead to the big resistance losses, high currents of consumption and, hence, low radiation efficiency as a whole. In a design of antennas it is required to provide power supplies and management input to the concentrated control elements of the antenna. These elements are in the field of the antenna and often create parasitic effects for which compensation it is necessary to complicate a design essentially.
In this paper possibility of creation of the conformal scanning reflective antenna with photonic control is investigated. The antenna reflector is executed in the form of the multilayered medium consisting of alternating dielectric layers and semi-conductor films on the metal emulsion carrier which conductivity changes under the influence of optical bombarding radiation. Depending on a condition of semi-conductor films on a surface of a reflector of the reflective antenna the cylindrical front of an incident wave is converted to flat front of the reflected. The mathematical model of the reflective antenna in the Kirchhoff approximation is gained. Radiation patterns are resulted at scanning in wide sector of angles. The variants of an antenna design are considered. In the capacity of one of applied application of a layer structure of semiconductor film and dielectric layers on a metal emulsion carrier creation of an antenna reflector is. Such antenna can be not only low profile, but also can possess conformal properties, that are having geometrical matching to a surface, for example flying or a space vehicle.