IEEE Approved Draft Standard for Rectangular Metallic Waveguides and Their Interfaces for Frequencies of 110 GHz and Above. Part 1: Frequency Bands and Waveguide Dimensions
This standard gives specifications for the waveguide (including aperture dimensions,frequency range, cut-off frequency, etc). This standard considers the tolerances of the waveguide aperture dimensions and the effect these have on the electrical properties (in terms of return loss, transmission loss, etc) of the waveguide.