Topic: Waveguides
A rectangular waveguide with air medium has dimensions a = 22.86 mm and b = 10.6 mm is fed by 3 GHz carrier from a coaxial cable, which of the following is false statement for TE10 mode?
- A. Propagating mode
- B. Non-propagating mode
- C. Propagating mode in case filled fully with dielectric material of proper dielectric constant
- D. None of the above
Answer: A. Propagating mode
Explanation: a = 22.86 mm, b = 10.6 mm, f = 3 GHz. As a > b, TE10 is dominant mode. Cut-off frequency for TE10 mode = c / (2a) = (3 x 10^8) / (2 x 22.86 x 10^-3) = 13.12 GHz. As input applied frequency is less than cut-off frequency, the mode is non-propagating.