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:
Oct. 12, 1993
Filed:
Jun. 09, 1992
Robert Bosch GmbH, Stuttgart, DE;
Abstract
An elongated rod 11 of dielectric material, for example fiberglass--plastic or the like, has a central conductor (12) located coaxially therein, the conductor having a length L=3/2 .lambda.; in the central .lambda./2 range, the insulating rod is surrounded by a conductive layer (13, 16, 20, 25), for example of conductive lacquer, a mesh or braid of conductive material, a conductive foil or tube or the like. In the lower .lambda./2 region of L1, the bottom terminal of the central conductor will provide a high resistance output for the higher one of the frequency ranges which, for example, can be a radio telephone, or vehicular communication frequency of between 450-470 MHz. The entire antenna is suitable as an AM-FM/radio-telephone combination antenna. .lambda. is the median operating wave length of the higher one of the frequency ranges for which the antenna is suitable. Preferably, the antenna is covered with a sleeve of insulating material, for example a heat shrinkable plastic (27). The band width of the antenna can be extended by placing a further electrically conductive layer (513, 619, 722, 828) on the rod, spaced by a gap (a) physically and electrically from the conductive layer (13, 16, 20, 25) in the middle of the elongated rod. The further conductive layer is .lambda./2 long, and connected to the inner coaxial conductor (12, 512), which in turn can be coupled to an antenna input, for example the center conductor of a coaxial cable of a radio apparatus.