Question

5. Cut-off frequency of an arbitrary TE or TM mode [Marks 1] Write a function cutoffFreq) in MATLAB that calculates the cut-off frequency of an arbitrary TE or TM mode in a rectangular waveguide, with the following input arguments: the intrinsic phase velocity of the waveguide dielectric, c, waveguide transverse dimensions, a and b, and mode indices, m and n.

Answer 1

Matlab Script:

function fc = cutoffFreq(c,a,b,m,n)
fc = (c/2)*sqrt(((m/a)^2)+((n/b)^2));
end

>> fc = cutoffFreq(3e8,0.01,0.005,2,1)
fc =    4.2426e+10

>> fc = cutoffFreq(3e8,0.04,0.03,2,2)
fc =    1.2500e+10