| 摘要 |
648,262. Aerials. STANDARD TELEPHONES & CABLES, Ltd. June 6, 1947, Nos. 15001, 15002 and 15003. Convention dates, June 19, 1946. [Class 40 (vii)] A radio slot antenna comprises a hollow conductive shell 1-5 surrounding and enclosing a toroidal space, a radiating slot 6 being formed in the wall, the slot returning on itself and having a width which is a small fraction of a wavelength. A coaxial feeder 8 energizes the slot at a first point, and means such as a shortcircuit 7 or a second feeder is coupled to the slot at a second point diametrically opposite the first whereby a voltage standing wave is produced along the slot having minima at the two points. The currents flowing between the edges of the slot are in phase, producing omnidirectional, vertically - polarized radiation. Conductive mast 10 supports the antenna. In attenuation embodiments, Figs. 2-6 (not shown), the shell is attached to, or is in part constructed of, a flat conductive sheet such as the skin of a vehicle or aircraft. In Figs. 7 and 8 (not shown), the slot is formed in a conductive sheet and is backed by a shell enclosing a toroidal space. The antennµ have broad-band characteristics. Suitable materials for constructing the antenna are sheet-metal, a conductively coated plastic or wire mesh. The shell and gap may be filled with a dielectric. Typical dimensions for the various embodiment are given in the Specification. Specification 638,020 is referred to. |
