Pulse surface wave in closed circular waveguide with dielectric rod pulse surface wave

Abstract

During a pulse signal propagation in a dielectric waveguide pulse surface wave can be excited. This wave represents a “precursor” of wave structure. Above mentioned wave have some parts inside the dielectric rod and near the rod surface. The field distribution for this wave inside the dielectric rod is a rhombus-shape and consists of cones similar to Cherenkov wavefront. A part of this wave propagates in free space near the dielectric surface with the speed of light in free space. This wave propagates along the waveguide with the speed of light in free space as a whole wave structure. Such a guided wave structure differs from conventional waveguide modes since it does not have the same transverse field distribution in any cross-section. First this effect was investigated as a wave structure created by a localized source inside the open dielectric waveguide. The aim of this paper is to consider excitation of such a wave in closed circular waveguide with a dielectric rod and explore the possibility to create some resonance devices using this wave type. For the calculations BOR-FDTD method was used with PML boundary conditions.