This standard gives specifi cations for rectangular waveguide interfaces. This standard considers the tolerances of the waveguide interface dimensions and the effect these have on the electrical properties (in terms of return loss) of the waveguide. Purpose The purpose of this standard is to provide a reference for all organizations using interfaces for rectangular waveguides at frequencies of 110 GHz and above. In addition to improving the compatibility of various waveguide components@ this standard facilitates effi cient trade between customers and suppliers@ and provides common design criteria and practices for component@ systems@ and design engineers