The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 15, 2000
Filed:
Dec. 24, 1996
Paul Dent, Pittsboro, NC (US);
Amer Hassan, Cary, NC (US);
James MacDonald, Apex, NC (US);
Yawei Ma, Cary, NC (US);
Ericsson Inc., Research Triangle Park, NC (US);
Abstract
An antenna operable in two disparate frequency bands is disclosed as including a first quadrifilar helix having four conductive elements arranged helically to define a cylinder of substantially constant radius, where the first quadrifilar helix is formed of two bifilar helices arranged orthogonally and excited in phase quadrature. A quadrature feed network is connected to the first quadrifilar helix, wherein one end of a coupling element thereof is connected to a first end of each conductive element. The quadrature feed network also includes a first feedpoint for operation of the antenna with circular polarization in a first frequency band and a second feedpoint for operation of the antenna with linear polarization in a second frequency band. The antenna may include a second quadrifilar helix connected to the quadrature feed network and having four conductive elements arranged helically to define a cylinder of substantially constant radius, where the second quadrifilar helix is formed by two bifilar helices arranged orthogonally and excited in phase quadrature. The second quadrifilar helix is wound in opposite sense with respect to the first quadrifilar helix so as to be conductively coupled therewith.