Round compartmented hollow waveguide for aerials - has rings forming pockets filled with two materials having different dielectric values

摘要

The hollow waveguide of round cross section and suitable for microwave aerials, such as parabolic mirrors, is divided into sections by internal partitions. The outer cylinder (1) has a set of rings (2) mounted on the inside, forming a series of annular compartments filled with dielectric material. This consists of an outer layer (3) of plastics foam and an inner layer plastics reinforced by A12O3. The input impedance of each compartment at the inner entry zone in wide frequency intervals has a higher capacitative value. The inner material has the higher dielectric value.