Which of the following is used for amplification of microwave energy?
36. Which one of the following can be used for amplification of microwave energy?…Exercise :: Microwave Communication – Section 4.
| A. | TWT |
|---|---|
| B. | Magnetron |
| C. | Reflex klystron |
| D. | Gunn diode |
Which of the following materials are generally preferred for waveguides?
Typically waveguide is made of brass, copper, silver, aluminum, or any metal that has low bulk resistivity. It is possible to use metals with poor conductivity characteristics, if the interior walls are properly plated. It is even possible to make plastic waveguide!
Which of the following is NOT type of waveguide?
Cavity resonator is not a waveguide. Explanation: The waveguides are operated in the GHz range. In particular, the waveguides are active above 6 GHz.
Which of the following conditions is not required for a waveguide to exist?
4. Choose which of following condition is not required for a waveguide to exist. Explanation: A waveguide need not be spherical, it has to be rectangular or circular, as it violates the propagation of the wave. Φ = tan-1(y/x) = tan-1(3/2) = 56.31⁰.
What is the dominant mode in rectangular waveguide?
The dominant mode in a particular waveguide is the mode having the lowest cutoff frequency. For rectangular waveguide this is the TE10 mode. The TE (transverse electric) signifies that all electric fields are transverse to the direction of propagation and that no longitudinal electric field is present.
Which is the dominant mode in rectangular waveguide Why?
Signals can progress along a waveguide using a number of modes. However the dominant mode is the one that has the lowest cut-off frequency. For a rectangular waveguide, this is the TE10 mode. The TE means transverse electric and indicates that the electric field is transverse to the direction of propagation.
What is the cutoff frequency of a rectangular waveguide?
The cut off frequency for the TEmn mode is fcmn = c 2π √(mπ a )2 + (nπ b )2 . The fundamental mode of a waveguide is the mode that has the lowest cut-off frequency. For a rectangular waveguide it is the TE10 mode that is the funda- mental mode. It has fc10 = c 2a .
What is the cutoff frequency of a waveguide?
The cutoff frequency of an electromagnetic waveguide is the lowest frequency for which a mode will propagate in it. In fiber optics, it is more common to consider the cutoff wavelength, the maximum wavelength that will propagate in an optical fiber or waveguide.
What is the range of frequency used in waveguide components?
The microwave spectrum is usually defined as a range of frequencies ranging from 1 GHz to over 100 GHz. This range has been divided into a number of frequency bands, each represented by a letter. There are a number of organizations that assign these letter bands.
What are the different types of frequency bands?
Frequencies as designated by the International Telecommunications Union
- 3 Hz-30 Hz. Wavelength: 10^8m-10^7m. Band: Extremely low frequency (ELF)
- 30 Hz-300 Hz. Wavelength: 10^7m-10^6m. Band: Super low frequency (SLF)
- 300 Hz-3 KHz. Wavelength: 10^6m-10^5m. Band: Ultra low frequency (ULF)
- 300 Hz-3 KHz. Wavelength: 10^6m-10^5m.
What are the types of waveguide?
There are five types of waveguides.
- Rectangular waveguide.
- Circular waveguide.
- Elliptical waveguide.
- Single-ridged waveguide.
- Double-ridged waveguide.
How do you choose a waveguide?
It is important to choose the right type of waveguide. Each type has different dimensions and this will give it different properties, the cut-off frequency being particularly important, along with the overall recommended frequency range. The material used in the waveguide will also help dictate some properties.
What is a mode in waveguide?
Waveguides have certain optical field distributions that stay constant during propagation, except for a change in the overall phase and possibly the optical power. Such field distributions, which depend on the refractive index profile, correspond to so-called waveguide modes.