Antenna performance of push-to-talk transceiver in VHF and UHF bands considering impedance matching

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.