中国物理B ›› 2010, Vol. 19 ›› Issue (1): 10302-010302.doi: 10.1088/1674-1056/19/1/010302
林琼桂
Lin Qiong-Gui(林琼桂)†
摘要: Cylindrical waveguides without end surfaces can serve as two-dimensional resonant cavities. In such cavities the electromagnetic oscillations corresponding to an eigenfrequency can always be taken as TM or TE modes even when the walls have a finite conductivity and the medium is absorptive. This paper obtains analytic solutions to the field equations when the cylinder has a circular cross section. Some nonperturbative conclusions are drawn from the eigenvalue equation. Approximate analytic results for the resonant frequencies are obtained when the absorption of the medium is small and the walls are good conductors. Stability of the eigen modes is discussed. Similar results for the coaxial line are presented.
中图分类号: (Classical electromagnetism, Maxwell equations)