Patent ID: 7456794

Claim:
A foldable mobile radio apparatus applicable in a first and second frequency band, comprising: a first case ( 1 ); an antenna element ( 17 ) that is provided to the first case ( 1 ); a second case ( 2 ) joined to the first case ( 1 ) by means of a hinge portion ( 3 ), wherein the hinge portion ( 3 ) has a rotation shaft ( 15 ) that joins the first case ( 1 ) and the second case ( 2 ) such that the first and second case are turnable around the rotation shaft, the second case ( 2 ) provides for a circuit board ( 13 ) that includes a ground pattern and a feeding portion ( 16 ), and the rotation shaft ( 15 ) is separated from the ground pattern of the circuit board ( 13 ); characterized in that the rotation shaft ( 15 ) is formed of conductive metal and is electrically connected to the feeding portion ( 16 ); the antenna element ( 17 ) is arranged at a predetermined interval from the rotation shaft ( 15 ) such that the antenna element and the rotation shaft are capacitively coupled; the rotation shaft ( 15 ) and the ground pattern of the circuit board ( 13 ) operate as λ/4-series monopole antenna whose resonance frequency is set in the first frequency band, when power is fed; and the antenna element ( 17 ), the rotation shaft ( 15 ) and the ground pattern of the circuit board ( 13 ) operate as a λ/2-series dipole antenna whose resonance frequency is set in the second frequency band, when power is fed.