AdvancedA-007-009-005
Which of the following statements about waveguide IS NOT correct?
D
Answer
Interference, EMC, and safety
Type
A
Waveguide has low loss at high frequencies, but high loss below cutoff frequency
B
In the transverse electric mode, a component of the magnetic field is in the direction of propagation
C
In the transverse magnetic mode, a component of the electric field is in the direction of propagation
D
Waveguide has high loss at high frequencies, but low loss below cutoff frequency
Answer Notes
Waveguides are hollow metal tubes used to transfer high-frequency RF energy, particularly at microwave frequencies. They act as a high-pass filter, meaning they have very low loss at frequencies above their specific cutoff frequency, but they severely attenuate (have high loss) at frequencies below that cutoff.
The question asks for the statement that is NOT correct. Option D reverses the reality of waveguide operation by claiming it has high loss at high frequencies and low loss below the cutoff frequency. This makes it the false statement, and therefore the correct answer.
The other options describe true properties of waveguides. They indeed have low loss at high frequencies, and their transverse electric (TE) and transverse magnetic (TM) modes correctly describe the alignment of magnetic and electric fields relative to the direction of propagation.
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For rectangular waveguide to transfer energy, the cross-section should be at least:
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Which of the following is a major advantage of waveguide over coaxial cable for use at microwave frequencies?