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Waveguides Summary

  1. The energy propagates in the waveguide conductor as an electromagnetic field.
  2. There are the most different waveguide cross-cuts. But only the waveguides are of practical importance, however, with a rectangular and round or elliptical cross-cut.
  3. The walls of the waveguide have only the function, to prevent that the electric magnetic waves deviate from the specified way.
  4. Waveguides have lower losses and are more charge as comparable coaxial cables.
  5. Waveguide haven't any practical meaning at frequencies by less than 1000 MHz because of the dependence of its geometric measurements of the transferred frequency.
  6. There are electrical fields only vertically to conducting areas, magnetic fields can there be only parallelly to conducting areas
  7. The fields are moving by reflection between the covers of the waveguide.
  8. Waveguide being able to be operated only above the critical frequency. Applies to the cutoff wavelength of rectangular waveguide: λcutoff = 2·a
  9. In the waveguide ongoing waves can only exist by exact termination with the impedance (E- and H-Feld in phase).
  10. Waveguide being able to be excited by probes in the E field maximum, by wire bows in the H field maximum and from outside by openings in the cover.
  11. We distinguish solid, semi-solid and rotating connections.
  12. To the avoidance of reflections bends and turns may not be suddenly carried out. The bend radius must be at least two wavelengths. The turn must at least extend over two wavelengths. For sharp bends only special angle pieces may be used.
  13. Standing waves can be measured with help of one into the waveguide established probe.