Coil impedance computation having arbitrary geometrical shape

Coil impedance computation having arbitrary shape is a relatively difficult task, because the inductance as well as resistance are not simple functions of the geometrical parameters but of frequency. In the present paper, the authors propose a new semi-analytical approach to compute the impedance vs. frequency characteristics of a coil having arbitrary shape. Any coils having complex geometrical shape can be divided into small conductors having simple geometrical shape. Applying analytical formulae to each of the small subdivided conductors, each of the inductances and resistances is easily calculated by an analytical approach. Combining entire inductances and resistances, taking into account the mutual inductances, yields an equivalent circuit of the original coil having complex geometrical shape. Establishing and solving a set of circuit equations about this equivalent circuit make it possible to evaluate the impedance vs. frequency characteristics of the coil. Simple examples verify their proposed methodology