Principle of Operation
Depending on the frequency, waveguides can be constructed from either conductive or dielectric materials. Generally, the lower the frequency to be passed the larger the waveguide is. For example the natural waveguide the earth forms given by the dimensions between the conductive ionosphere and the ground as well as the circumference at the median altitude of the Earth is resonant at 7.83 Hz. This is also known as Schumann resonance. Waveguides can also be less than a millimeter in width. An example might be those that are used in extremely high frequency (EHF) communications.
Read more about this topic: Waveguide (electromagnetism)
Famous quotes containing the words principle of, principle and/or operation:
“The first principle of a free society is an untrammeled flow of words in an open forum.”
—Adlai Stevenson (1900–1965)
“I do not mean to exclude altogether the idea of patriotism. I know it exists, and I know it has done much in the present contest. But I will venture to assert, that a great and lasting war can never be supported on this principle alone. It must be aided by a prospect of interest, or some reward.”
—George Washington (1732–1799)
“An absolute can only be given in an intuition, while all the rest has to do with analysis. We call intuition here the sympathy by which one is transported into the interior of an object in order to coincide with what there is unique and consequently inexpressible in it. Analysis, on the contrary, is the operation which reduces the object to elements already known.”
—Henri Bergson (1859–1941)