Eigenmodes of a gyrotron cavity with anisotropic impedance surface

Coupled first-order differential equations are obtained for the field amplitudes of a single wave in cylindrical weakly irregular waveguide with anisotropic impedance surface. The equations are valid for both types of hybrid waves. For closed uniform cavity with ideal side walls, they yield analytical solution to eigenvalue problem. For open gyrotron cavity, they reduce to known form as impedance approaches zero. Gyrotron cavity with anisotropic wall impedance of special form is considered as numerical example.