Antenna device for radio apparatus

摘要

Feed point ( 101 ) performs unbalanced feeding to an antenna element ( 102 ). A parasitic element ( 104 ) is provided near the antenna element ( 102 ) and a ground plane ( 103 ), approximately parallel to the width direction of the ground plane ( 103 ). Moreover, the parasitic element ( 104 ) is configured in a length to operate as a director when provided on the side of the body with respect to the ground plane ( 103 ) during talk time and in a length to operate as a reflector when provided on the opposite side from the body with respect to the ground plane ( 103 ). By this means, it is possible to improve gain and reduce the specific absorption rate (SAR) during talk time.