Patent ID: 6828944
Filing Date: 2004-12-07
Classification: H01Q

Abstract:
A multi-band sleeve dipole antenna comprising:a generally axially disposed elongate inner conductor having first and second ends and arranged to be connected at said first end thereof to a modulated signal source; a generally axially disposed intermediate conductor disposed generally coaxially with respect to said inner conductor and arranged to be connected to ground; a generally axially disposed first outer sleeve conductor disposed generally coaxially with respect to said inner conductor and to said intermediate conductor; and a generally axially disposed second outer sleeve conductor having a first and second ends disposed generally coaxially with respect to said inner conductor and to said intermediate conductor, said first end being adjacent and axially separated from said first outer sleeve conductor by an axial gap, said first outer sleeve conductor being electrically connected to said intermediate conductor at a feed point location along said inner conductor which is axially separated from said second end thereof by a distance generally equal to one-quarter wavelength of a first radio transmission frequency, said first outer sleeve conductor extending beyond said feed point location by a distance generally equal to one-quarter wavelength of a second radio transmission frequency, which is higher than said first radio transmission frequency, said second outer sleeve conductor being electrically connected to said inner conductor at a location at said second end of said second outer sleeve conductor, and said first end of said second outer sleeve conductor being axially separated from said second end of said inner conductor by a distance equal to one-half wavelength of said second radio transmission frequency.