| 摘要 |
An antenna structure 10, or a method of using such an antenna structure, comprises: one or more antenna elements 14 spaced apart from an outer structure 12 which includes a non-reciprocal metamaterial and which transmits electromagnetic radiation 20 incident on the outer periphery of the outer structure 12 and inhibits electromagnetic radiation which strikes the inner periphery of the outer structure 12 and which is coming from the direction of the antenna elements 14. The metamaterial may be an active element of the antenna and may comprise of an array of unit cells which may each comprise a loop element linked to a monopole element via an amplifier. The said radiation 20 incident on the outer periphery of the outer structure may be transmitted with substantially no reflection whilst the radiation striking the inner periphery of the outer structure may be reflected with substantially no transmission. The outer structure 12 may be spaced 18 by a distance of 20mm or less from the antenna elements 14. The said spacing 18 may be an air gap layer or a layer of foam or a polymeric material such as rubber. The antenna elements 14 may be GPS patch elements. The structure 10 may be used in vehicles, buildings or other structural installations. |
