IMPEDANCE OF A SINGLE-TURN COIL DUE TO A DOUBLE-LAYERED SPHERE WITH VARYING PROPERTIES

This paper presents an analytical solution for the change in impedance in a coil due to the presence of a conducting double-layered sphere s ymmetrically situated with respect to the coil. In the case the relati ve magnetic permeability, mu(r) = r(alpha), of the outer sphere is a f unction of the distance r from the center of the sphere, where alpha i s an arbitrary real number, the solution is expressed in the form of a series containing Bessel functions and can be used to compute the cha nge of impedance. Numerical results for the case alpha = -2 are presen ted.