New coupled-domain technique for fast 3-D simulation of long slow-wave structures

Summary form only given, as follows. We present results of a new model for fast electromagnetic simulation of slow-wave structures, which effectively derives small, equivalent-circuit representations directly from 3-D finite-element simulations of real cavity geometries. To model an entire interaction structure, circuit representations obtained for specific cavity geometries may be arbitrarily coupled together. The coupled system need not be periodic and may therefore include tapers, severs or distributed loss. The resulting global matrix equation has a relatively small number of unknowns and is readily solved to obtain dispersion or propagation characteristics of the traveling-wave circuit. We will demonstrate that our method generalizes equivalent circuit models, deriving a reduced system of equations directly from the device geometry. In addition, the method provides the gap fields without further assumptions, and the reduced representation may be tailored to achieve an arbitrary level of accuracy, at the cost of an increased number of equations and unknowns.