Guide Wavelength Measurements
| Assignment 2 | Guide wavelength measurements | |
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Abstract
The purpose of this experiment is to demonstrate:
a) The techniques for measuring guide wavelength.
b) The relationship between the wavelength in free space and the guide wavelength.
Furthermore, this experiment will be a way in which to gain experience in using different types of laboratory communications equipment.
Introduction
What is wavelength?
Wavelength of a sinusoidal wave is the distance between identical points in the adjacent cycles of a waveform signal. Wavelength is commonly designated by the Greek letter lambda (λ)Wavelength is inversely correlated to frequency (figure 1.1), therefore the higher the frequency of the signal, the shorter the wavelength. vp Is the phase velocity f is the frequency
vp Is the phase velocity f is the frequency
λ=vpf
Figure 1.1
What is a wave guide?
Figure 1.2
A waveguide is a special form of transmission line consisting of a rectangular (figure 1.2) or cylindrical metal tube or pipe, through which electromagnetic waves are propagated in microwave and RF communications. It is commonly used in microwave communications, broadcasting, and radar installations.
A waveguide must have a certain minimum diameter relative to the wavelength of the signal and therefore are practical only for signals of extremely high frequency. Consequently below such frequencies, waveguides are useless as electrical transmission lines.
“An electromagnetic field can propagate along a waveguide in various ways. Two common modes are known as transverse-magnetic (TM) and transverse-electric (TE). In TM mode, the magnetic lines of flux are perpendicular to the axis of the waveguide. In TE mode, the electric lines of flux are perpendicular to the axis of the waveguide. Either mode can provide low loss and high efficiency as long as the interior of the waveguide is kept clean and dry.”
Some disadvantages are: * The high cost, since the material
|
Abstract
The purpose of this experiment is to demonstrate:
a) The techniques for measuring guide wavelength.
b) The relationship between the wavelength in free space and the guide wavelength.
Furthermore, this experiment will be a way in which to gain experience in using different types of laboratory communications equipment.
Introduction
What is wavelength?
Wavelength of a sinusoidal wave is the distance between identical points in the adjacent cycles of a waveform signal. Wavelength is commonly designated by the Greek letter lambda (λ)Wavelength is inversely correlated to frequency (figure 1.1), therefore the higher the frequency of the signal, the shorter the wavelength. vp Is the phase velocity f is the frequency
vp Is the phase velocity f is the frequency
λ=vpf
Figure 1.1
What is a wave guide?
Figure 1.2
A waveguide is a special form of transmission line consisting of a rectangular (figure 1.2) or cylindrical metal tube or pipe, through which electromagnetic waves are propagated in microwave and RF communications. It is commonly used in microwave communications, broadcasting, and radar installations.
A waveguide must have a certain minimum diameter relative to the wavelength of the signal and therefore are practical only for signals of extremely high frequency. Consequently below such frequencies, waveguides are useless as electrical transmission lines.
“An electromagnetic field can propagate along a waveguide in various ways. Two common modes are known as transverse-magnetic (TM) and transverse-electric (TE). In TM mode, the magnetic lines of flux are perpendicular to the axis of the waveguide. In TE mode, the electric lines of flux are perpendicular to the axis of the waveguide. Either mode can provide low loss and high efficiency as long as the interior of the waveguide is kept clean and dry.”
Some disadvantages are: * The high cost, since the material