Analysis of electric field distribution near car in radio remote control system for electric equipment installed in car

Radio remote control systems for electric equipment have been installed in cars. As an example of the typical systems, there is the multi-function remote keyless entry system with the door lock/unlock and the trunk release. In this system, a receiving antenna is built in the receiver and set in the car cabin. Characteristics of the antenna set in the car cabin differ from those of the only antenna element because they are largely affected by the car body. Moreover, it is expected that effects of the car body complicatedly vary with the change of positions and types of the antennas. Accordingly, we consider that it is necessary to analyze the electromagnetic field distributions near the car body and design the antenna system in consideration of surrounding objects, such as the car and a human body. In this paper, we propose an analytical model of the radio remote control systems for the electric equipment installed in the car, and describe numerical results of electric field distributions near the car body at a frequency of 300 MHz.