Broad band dipole antenna
AssigneeU.S. Philips Corporation
InventorKnut E. Cassel
Life of this patent
Estimating the term…
Abstract
A dipole antenna consisting of a number of sub-elements, each sub-element comprising a plurality of thin electric conductors or strips of wires arranged on the surface of an insulating cylinder. The conductors in each sub-element have the same length and are distributed around the circumference of the cylinder, so that each such sub-element forms a so-called "thick" dipole element. The lengths of the conductors in different sub-elements are different, so that the sub-elements together will cover a broad frequency band. At least each conductor in the group having the longest conductors are provided with inductive reactances, to prevent excitation of said longer conductors in higher modes at resonance frequencies of the shorter conductors.
Claims12
In a broad band dipole antenna having at least one dipole element adapted to be fed at one end thereof, said dipole element comprising a plurality of groups of sub-elements, the sub-elements of each group having the same electrical length and the sub-elements of different groups having different electrical lengths, the longest sub-elements being electrically connected together at the other end of said dipole element, whereby said antenna has broad band characteristics;
- the improvement comprising series reactances in the longer of said sub-elements for inhibiting excitation thereof at frequencies higher than those corresponding to its length, said series-reactances being each formed by the input impedance of a resonator extending along portions of said longer sub-elements said resonator having an input facing said one end of said dipole element.
Dependencies are inferred from the claim text.