| 摘要 |
An omni-directional aerial, more especially for the reception of domestic television programmes in the U.H.F. band comprises four folded dipole elements (1-4) each formed as a self-supporting open-ended wire loop (1A, 1B, 1C, 1D) integral with twin feeder portions (1E, 1F; 2E, 2F; 3E, 3F; 4E, 4F). The loops are aranged in planes parallel to a common central axis and are regularly angularly displaced about this axis so that opposed pairs of loops lie in parallel planes. The twin feeder portions (1E, 1F; 2E, 2F; 3E, 3F; 4E, 4F) are connected in common to respective terminal means at the central axis and each pair of feeder portions of each loop extend parallel to one another in a plane radial to the central axis which enables simple matching of the impedance of the aerial to a connecting cable. |
