John Stephen Eberhardt

US Patent:

52314120, Jul 27, 1993

Filed:

Oct 18, 1991

Appl. No.:

7/780663

Inventors:

John E. Eberhardt - Plantation FL
Oscar M. Garay - Coral Springs FL
Yew S. Tay - Plantation FL

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H01Q 9320
H01Q 11080

US Classification:

343790

Abstract:

An antenna (100) includes a quarter-wave monopole radiating element (110, 110') having a signal feed point end (110A). The antenna (100) further includes a reactive element (150) in the form of a conductive sleeve. The sleeve (150) includes a grounding end (150A) and is coaxially positioned around a portion of the monopole radiating element (110, 110'). A spacer (140) is coaxially situated between the monopole radiating element (110, 110') and the reactive element (150), for electrically insulating the monopole radiating element (110, 110') from the reactive element (150). The spacer (140) is sufficiently dimensioned such that the monopole radiating element is tightly coupled to the reactive element (150) at substantially around the feed point end (150A).