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:
Mar. 01, 1983
Filed:
Jul. 20, 1981
Horst Dorrie, Berlin, DE;
Kurt Klinkwitz, Berlin, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
To provide a short FM antenna, of about for example 40 cm length for mobile radio, for example automobile radio application, without degradation of signal strength with respect to an about 1 m long FM antenna, a conically tapering insulating rod, for example of fiberglass, has two windings applied thereover, the two windings, each, having a straight wire length of about 1/4 the median wavelength of the FM band, and the overall length (l) of the rod having said two windings applied thereover being about 1/8 of the median wavelength. The oppositely wound windings (11, 12) are connected at their center, and may be formed as one bifilar winding, with the lower end of the lower winding being connected to an electrical terminal for standard connection to, for example, a coaxial antenna connector for an automobile radio. A spiral spring can be interposed if extreme deflectability of the antenna is desired, for example to prevent damage if the antenna, applied to an automotive vehicle, is passed through a power washing and scrubbing station.