Characteristics Analysis of a Coaxial Cavity With a Misaligned Inner Rod

The effects of a small misalignment of the inner rod in a coaxial cavity on the cutoff frequencies and the ohmic quality factors of TE modes are investigated. For axially symmetric modes, the cutoff frequencies decrease and the ohmic quality factors increase when the misalignment of the inner rod increases. The effects are more noticeable for axially symmetric modes with a larger radial index and coaxial cavities with a larger ratio of the inner and outer radii. For axially asymmetric modes, there exists a critical value near the caustic radius. When the inner rod radius is smaller than the critical value, the cutoff frequencies are slightly affected by the misalignment, and the ohmic quality factors decrease with the increase of the misalignment. When the inner rod radius is greater than the critical value, the cutoff frequencies and the ohmic quality factors increase with the increase of the misalignment, and the effects are more noticeable for a larger inner rod radius.