Patent ID: 6956533
Filing Date: 2005-10-18
Classification: H01Q

Abstract:
1. A monopole roof antenna, for use with at least two wireless communication services, of different frequencies comprising; a monopole element structured essentially along a straight line, a roof capacitor that is structured essentially as a flat area, and disposed substantially perpendicular to the straight line, and connected with said monopole element, said roof capacitor being essentially structured with rotation of symmetry, and comprising a plurality of flat ring structures that are separated from one another by ring-shaped gaps of said monopole element, said ring structures being disposed concentric to the straight line, reactance circuits disposed in said ring-shaped gaps and coupled to adjacent ring structures in a frequency-dependent manner, so that all of said flat ring structures are active for a wireless communication service having the lowest frequency, and wherein said outermost ring structure is essentially ineffective for the wireless communication service having the next higher frequency, because of the high impedance of said reactance circuits, and wherein for more than two wireless communication services, the dimension of the outermost of the active ring structures connected with one another by means of the low impedance of said reactance circuit is smaller at a higher frequency of the wireless communication services.