| 摘要 |
Disclosed is a wireless transmitting and receiving antenna which comprises a bobbin made of insulation material and having a first penetration cavity in the center of the bobbin in a lengthwise direction; a first antenna comprising a helical conductor spirally wound on the bobbin and having a resonance frequency, and a matching bar inserted into the cavity of the bobbin, made of a conductor and providing a second penetration cavity in the direction identical with that of the first penetration cavity; a feeder positioned at one part of the bobbin so as to supply signals to the helical conductor; and a second antenna comprising: a rod inserted into the penetration cavities of the bobbin and the matching bar, moving between the penetration cavities in a slipping manner, and wrapped with the insulation material; a conduction material combined to the outer part of the rod, and electrically connecting the feeder and the helical conductor when the rod is inserted into the penetration cavities; and a stopper which is made of a conductor, positioned at the lower part of the rod, and when the rod. is drawn Afro, the penetration cavity, the moving of the stopper is limited, and it is contacted to the feeder so as to supply signals to the rod.
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