Eigenfrequency analysis of a coaxial cavity with large eccentricity

A numerical approach is presented to analyze the eigenfrequency of a coaxial cavity with large eccentricity. An example is given to a lower mode TE₁₁₁ to compare with the software HFSS, where the eccentricity is up to 70%. Generally, this approach has the following peculiarities: the CPU time needed is much less than that needed by the software HFSS and especially, the calculation can be easily extended to higher-order mode such as TE_28,16,11as well as to high-frequency domain of hundreds giga hertz, which the software HFSS hardly reaches.