Power transfer for a running automobile

We herein propose power transfer through a capacitor composed of a steel belt in a tire and a metal plate attached to the road. In the present study, metal plates were arranged above and below a tire, and the complex impedance between these plates was measured. A matching circuit bridging the large impedance gap between the tire and 50-ohm lines was designed, and the transmission property was simulated. The measurement revealed that the real and imaginary parts of the complex impedance at 1 MHz were approximately 700 ohm and -2,000 ohm, respectively. For the matching, S
₂₁
was confirmed to be approximately -0.1 dB.