Oversized Rectangular Waveguide Components for mm Waves

For mm- and sub-mm waves, standard-size rectangular waveguide has several drawbacks, which are more or less overcome by the use of oversized waveguide. The latter has the following advantages: 1) The broadband property (possibly one frequency decade) which is shared by the greater part of the components discussed in this paper. Also simultaneous transmission of several frequencies with large separations (multiplex) is possible. Other broadband transmission lines, e. g. coaxial- or strip line deserve no consideration due to their high losses. 2) The comparatively low value of the attenuation. 3) The large physical dimensions.