Patent ID: 7053850
Filing Date: 2006-05-30
Classification: H01Q

Abstract:
1. A multiband antenna comprising a lower radiator and at least three upper radiators, all of the radiators spaced from each other and disposed on the same longitudinal axis, a first transmission line extending to a first feed point located between and connected to the lower radiator and one of the upper radiators, a second transmission line extending to a second feed point connected to at least two of upper radiators, the lower radiator and the upper radiators forming a dipole radiator centered on the first feed point that resonates in a lower frequency band for signals transmitted along the first transmission line, and at least two of the upper radiators forming a dipole radiator centered on the second feed point that resonates in a higher frequency band for signals transmitted along the second transmission line, and at least two isolation circuits connected between the upper radiators, wherein the isolation circuits resonate at different frequencies within the lower frequency band.