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There are such outside door handles called smart handles which have a transmitting antenna, a lock/unlock sensor, and a sensor detection circuit, with which operation of door lock is possible just by "touching" the electrostatic-capacitance type sensor of the handles.As the design of the outside handles, body color painting and Cr plating are adopted. However, if plating is applied over the entire surface of a smart handle, electromagnetic waves transmitted from the antenna will be blocked since plating material is electrically conductive. In addition to this, touching a part other than the sensor may change the electrostatic-capacitance of the sensor, which results in unwanted functioning of the lock/unlock sensor. Because of this, only part of the handle, which does not hinder the transmission of electromagnetic waves and does not cause unwanted functioning, is covered by plating, that is called, "Partially plated specifications" (Figure 1).

The wireless charging system of electric vehicles will be of high power. Due to environmental problems and the heat emission design of the machines, it is not easy to improve the efficiency of the power transmitting system. While improving the efficiency of the overall system is important, it is especially significant to improve the efficiency of the transmitting and receiving antennas. Improving the antennas is necessary as it accounts for a large part of the overall efficiency and it has strong relation to the transfer characteristics. In this paper, the importance of reducing the antenna loss for high power implementation is discussed. We showed that the antenna losses not only affecting the transfer efficiency but also the maximum power consumed by the load (the available power) by deriving an equation.

This year is being called the “first year of electric vehicles,” and electric vehicles have come on the market in earnest. This trend is expected to continue and even accelerate with the diffusion of electric vehicles. However, manually charging the battery for electric vehicles is a tedious process. Therefore, an automatic, wireless charging system for electric vehicle is greatly desired. There are some types of wireless power transfer systems. In particular, electromagnetic resonant coupling is a promising technology for wireless power transfer because power can be transferred over a large air gap; this method is more practical and efficient than the conventional methods. This technology has been proposed recently, and detailed study on the repeater antenna is yet to begin.