PURPOSE: To provide an antenna system capable of realizing a wide band antenna characteristic and obtaining an operation high in reliability and simple in structure without the use of a mechanical switch by providing a movable antenna in electrostatic coupling with a stationary antenna and in which the electrostatic coupling position is variable depending on the movement of the equipment itself and a support means supporting the movable antenna.

CONSTITUTION: A capacity component of a notch antenna 2 in a stationary state and an inductance component thereof are selected to be in parallel resonance with respect to the operating frequency. Then the static capacitance of an electrostatic coupling section 8 comprising ends of the rod antenna 1 and the notch antenna 2 and the inductace component of the rod antenna 1 form a constant K-type band pass filter with respect to the operating frequency. Furthermore, the rod antenna 1 is locked at an optional position extended/ contracted by a rubber-made ring 6. Then a wide band characteristic for the operating frequency band is attained by forming the constant K-type band pass filter with respect to the operating frequency band.