| 摘要 |
An omnidirectional receiving antenna primarily intended for TV signals and constituted of substantially circular antenna elements, tuned for different TV frequency ranges, connected to an amplifier and cast into a common casing, each antenna element comprising a double dipole antenna, one part of which is of circular shape and made of a metal plate or metal net cut open diametrically from one edge nearly to the opposite edge so as to form a slightly widening slot, and the other part being a metal band or similar extending substantially along the edges of the circular plate or net and at a certain distance therefrom, the ends of the band turning symmetrically inwards at the unbroken edge left by the cut and extending along the edges of the slot and being finally connected to the cut-open edge of the circular part on each side of the slot. Preferably, the antenna comprises several, for example three elements of different diameter and arranged concentrically with and above each others on a common central mast, the elements having a joint amplifier and being cast into a supporting material surrounded by the casing. |
