Abstract
A semianalytical method for the design and analysis of high-efficienty (>50%) generation of radiation in traveling output structures is presented. No a priori assumption about the functional form of the electromagnetic field is required. The concept of scalar interaction impedance used in periodic structures is generalized to a matrix in the case of a nonperiodic system. Its eigenvalue is shown to be directly related to the beam-wave interaction efficiency. The method is demonstrated with the design and analysis of a 70% efficiency system.