摘要 |
An antenna system for use in transmitting and receiving beams of electromagnetic waves of frequencies up to and including the sub-millimetre region of the spectrum comprises a horn (1) and a lens arrangement (4, 5) all of which are of a dielectric material. The feeder (1) may be solid or hollow and may be moulded integrally with a lens. Preferred dielectric materials are low loss media such as polyethylene. The antenna is cheap and easy to manufacture and has efficiency at least as good as quality precision metal antennae. |