Analytical expression to impedance for solenoid coil with a coaxial cylindrical ferrite core of finite length

摘要

Both numerical methods and analytical methods can be used to solve the electromagnetic field of a solenoid coil with a coaxial cylindrical ferrite core of finite length. Since numerical methods cannot give the explicit dependence of the field on the electromagnetic parameters and dimensions of the ferrite core and the coil, this paper presents an analytical method to solve such a problem and obtains an analytical expression for the coil impedance. The results obtained by the present method are in good agreement with the experimental results and also with the results obtained by a finite element method. This paper also gives some curves that show the variation of the coil impedance due to the scattering field with different electromagnetic parameters and dimensions of the ferrite core. [References: 6]