Detection Range of Distance Sensor Using Magnetic Resonant Coupling with Switching Function of Matching Circuit

Abstract

Distance sensors using electromagnetic field have advantages of simply configuration and strongly to environment change. However, these sensors are short operating distance because the electromagnetic energy is strongly attenuation depending on the distance. Therefore, a distance sensor using magnetic resonant coupling was proposed. In this study, a distance sensor using magnetic resonant coupling with a switching function of a matching circuit is proposed for further long distance detection. A detection range of the distance sensor is examined from measurement and calculation. As a result, it is clarified that the distance sensor can be detected a ratio of a length l between transmitting and receiving coils to inner diameter d of coil l/d = 0 to 1.5 by switching with or without matching.