Universal attenuation curves for rectangular and circular waveguide

Graphs give the value of attenuation constant against a normalized frequency, so that the characteristic free-space wavelength is measured in units of the broad dimension of rectangular waveguide or the diameter of circular waveguide. The results can then be scaled to any size of waveguide. One graph gives the results for the first fourteen modes in rectangular waveguide and the other those for the first fifteen modes in circular waveguide.