2025 年 14 巻 6 号 p. 238-241
This study considers the electromagnetic coupling between two Hertzian dipoles located in two- and three-dimensional free spaces. First, we briefly review the generalized kQ theory with respect to the reciprocal two-port impedance matrix. The kQ concept is then applied to a basic 2D problem, where a pair of Hertzian dipoles is sandwiched between infinitely wide parallel conductor plates. One dipole is excited by a sinusoidal current, and the other dipole observes the voltage induced across it. Solving a 2D Helmholtz equation yields kQ=√λ/d/π, where λ is the wavelength and d is the distance between the dipoles. Similarly, we apply the kQ theory to a 3D problem and obtain kQ=3λ/4πd. Because a Hertzian dipole is a building block for practical antennas, the results of this study will offer a theoretical foundation for developing various types of wireless power transfer systems.
