Mode Analytical Study of Cylindrical Cavity Power Combiners

A mode analytical treatment of cylindrical cavity power combiners is presented to discuss power-combining capability and the method for attaining stable desired mode operation. Both the conventional coaxial-probe output type and the window output type are treated, based on a circuit model which can support TM₀₁₀, TM₀₂₀, and TM_m10 modes (1<=m<=N, N being the number of active devices employed). It is shown that adoption of the window output largely facilitates undesired mode suppression and also enables power combining in some azimuthal modes.