Patent ID: 7477199
Filing Date: 2009-01-13
Classification: H01Q

Abstract:
1. An antenna device of a radio apparatus usable at a first frequency and at a second frequency, comprising: a fed partial element including a fed portion, a first branch portion and a second branch portion, the fed partial element configured to be fed at the fed portion, the fed partial element being formed in such a manner to be extended from the fed portion to the first branch portion with a width; a folded partial element branching off from the fed partial element at the first branch portion, the folded partial element including a forward path from the first branch portion to a fold portion and a backward path from the fold portion to a grounded end, the folded partial element and a path on the fed partial element from the fed portion to the first branch portion having a summed length of about a half wavelength of the first frequency, the grounded end located no greater than a one-fifth wavelength of the first frequency apart from the fed portion, the forward path and the backward path short-circuited at a bridge portion; and an open-ended partial element branching off from the fed partial element at the second branch portion, the open-ended partial element having an open end, the open-ended partial element and a path on the fed partial element from the fed portion to the second branch portion having a summed length of about a one-fourth wavelength of the second frequency.