Patent ID: 6552692
Filing Date: 2003-04-22
Classification: H01Q

Abstract:
An antenna comprising:a center-fed coaxial dipole having a first element and a second element for radiating and receiving electromagnetic energy in a plurality of frequency bands; the second element comprising a first portion and a second portion, whereupon the first element, the first portion and second portion each have a length equal to approximately one-quarter wave length of approximately the mid-range of each frequency band, the first element configured as a whip; the first portion configured as an inner conductive cylindrical sleeve coaxially aligned with the whip; the second portion configured as an outer conductive cylindrical sleeve coaxially aligned with the inner sleeve and the whip; a coaxial conductor having inner and outer conductors and being axially aligned with the dipole and extending through the second element of the dipole; the inner conductor being electrically connected to the whip and the outer conductor being electrically connected to the second element; a coaxial choke formed of a cylindrical sleeve of electrically conductive material disposed about and axially aligned with the coaxial conductor with the choke having a length equal to approximately one-quarter wavelength of the frequency at approximately the mid-range of one of the frequency bands; a first end of the choke remote from the dipole being connected to the outer conductor of the coaxial conductor; and a second end of the choke nearest to the dipole being spaced from the second element by a distance equal to approximately one-quarter wavelength of the frequency at approximately the mid-range of one of the frequency bands.