# Solved Problems-5

Problem-5

A rectangular waveguide with dimensions 2.42 cm Ã— 1.12 cm supporting

*TE*_{10}mode at 6 GHz is filled with a dielectric of relative permittivity*Îµ**. What are the limits on*_{r}*Îµ**if only the dominant mode propagates?*_{r}Solution

Here,
If only the dominant mode is to propagate, the cut-off frequency should be equal to the operating frequency.

Also, the cut-off frequency can be given as,

So, the limits are

*a*= 2.42 cm,*b*= 1.12 cm,*m*= 1,*n*= 0,*f*= 6 GHzAlso, the cut-off frequency can be given as,