  In this article, two analytical formulas for the calculation of mutual
inductance between a circular filament and line segment arbitrarily positioning
in the space are derived by using Mutual Inductance Method (MIM) and Babic's
Method (BM), respectively. Using the fact that any curve can be interpolated by
a set of line segments, a method for calculation of mutual inductance between a
circular filament and filament having an arbitrary shape in the space is
proposed based on the derived analytical formulas. The derived two formulas and
the proposed method (Segmentation Method) were numerically validated by using
FastHenry software and reference examples from the literature. In particular,
the proposed method was successfully applied to the calculation of mutual
inductance between the circular filament and the following special curves such
as circle, circular arc, elliptic arc, ellipse, spiral, helices and conical
helices. All results of the calculation are in good agreement with the
reference examples.
