放送事業用連絡無線はVHF帯(165MHz)，およびUHF帯(460MHz)を使用し，報道や番組制作における連絡手段として利用されている.本稿では，携帯型無線機をモデル化し，人体頭部近傍に無線機を設置したとき，人体とアンテナの距離，および人体の姿勢がアンテナ利得，放射パターンへ与える影響，さらに人体の電磁波曝露量について数値人体モデルを用いて検討した.その結果，人体からアンテナを100mm程度離すことによって，アンテナ利得の低下を防ぐことが可能であり，さらに電磁波曝露量を小さくできることがわかった.%The push-to-talk communication line for broadcasting services is used in the VHF band (165 MHz) and UHF band (460 MHz) in Japan. It is used for communication between staff during news gathering, television and radio program production, and so on. We designed a helical antenna with a metallic case as a handheld type transceiver and calculated the characteristics of the antenna with a numerical model of the human body. To investigate the effect of the human body on the performance of the antenna and the specific absorption rate on the human body, we calculated the antenna gain, radiation patterns and SAR when the antenna is in close proximity to the face. From these results, we propose using push-to-talk transceivers at a distance "d" that is more than 100 mm from the view point of antenna gain and SAR.
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