Waveguide & Wavelength
Rectangular Waveguide Cut-off Frequency Calculator
TE10 cut-off frequency and the usable single-mode band from the waveguide's broad wall width.
Result
Enter the inputs above and select Calculate.
Formula: f_c = c / (2a) · usable band ≈ 1.25 f_c to 1.89 f_c
The recommended band starts above cut-off, where the guide wavelength has settled, and ends before the TE20 mode can propagate.