Corrugated elliptical waveguide with permanent twist

摘要

A corrugated elliptical waveguide comprises a unitary, fluid-impervious, corrugated metallic tube with a substantially elliptical cross section. The corrugated tube is permanently twisted about its longitudinal axis for connecting two terminals having their E planes out of register with each other. The twist is uniformly distributed along a predetermined length of the corrugated tube. The twist is formed by twisting a corrugated circular waveguide about its longitudinal axis and simultaneously converting the circular cross section to an elliptical cross section, thereby causing the twist to be set in the elliptical waveguide.