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:
Jan. 01, 2002
Filed:
Jun. 16, 2000
Kent Falk, Mölnlycke, SE;
Ingmar Karlsson, Kållered, SE;
Telefonaktiebolaget LM Ericsson (publ), Stockholm, SE;
Abstract
The invention sets forth an aerial (1) having at least one plane spiral arm (3 . . . 3 ) being provided in front of and parallel with a plane face of a reflecting member (4), the aerial furthermore having a ferro-electric member (2) arranged between the at least one spiral arm (3 . . . 3 ) and the reflecting member (4). An interface circuit provides an adjustable bias voltage over the at least one arm (3 . . . 3 ) and the reflecting member (4) for varying the dielectric constant of, and thereby the delay through, the ferro-electric member (2). In this manner, the aerial is tuned to various frequencies of interest and providing for an enhanced antenna gain. According to a further aspect of the invention an interface circuit provides individually controllable bias voltages to respective spiral arms for accomplishing tuning of the axial ratio and/or impedance match of the aerial.