Calculation approach of the RF-field distribution in an eccentrically coaxial cavity

A calculation approach for evaluating RF-field distribution in an eccentrically coaxial cavity is proposed, where the theoretical model is based on the solution of scalar Helmholtz equation. Numerical analysis is carried out to compare with the software HFSS that is based on the finite element method. It is found that, although the results obtained by these two methods are in close agreement for lower-order modes, both the calculation time and memories used by the present approach are much less than that needed by the software HFSS, and especially, the present approach is still valid for the higher-order mode such as TE_28,16,1and higher frequency up to hundreds giga hertz which the software HFSS can hardly process.