Recommendations for waveguide sizes at submillimeter wavelengths

This paper gives recommendations for specifying sizes of rectangular waveguides for use at submillimeter wavelengths (i.e. at frequencies above 300 GHz). The proposed sizes are compatible with both existing waveguide sizes used at millimeter-wave frequencies (to 300 GHz) and the International System of units (SI). Waveguide sizes are developed in detail to 1.1 THz, then these are extended to cover the entire submillimeter-wave band (to 3.3 THz).