| 摘要 |
<p>An aerial for electromagnetic radiation comprises a lens (65) of dielectric material transparent to the radiation and having a dielectric constant substantially equal to 3.414. A convex surface portion is provided with a metallic layer (65) for reflecting the radiation and an electrical connection (64) is provided to the reflecting surface for carrying the aerial signal. The lens material may be silica glass beads or silica flour bound together by an adhesive, preferably a polyester resin binder with the reflective layer coated on the outside of the lens. The lens may be spherical or alternatively it may have a plane of symmetry (32) and formed such that the lens is axially symmetric with the lens surface having a radius of curvature that increases as the distance from the axis increases. The lens may comprise a polycarbonate shell (36) formed of two halves and filled with particulate silica flour. The reflecting layer is provided on the inner surface of the lens shell.</p> |
