In electromagnetics and communication engineering, the term waveguide can refer to any linear structure that transmits electromagnetic waves between its endpoints. But at first [1] and most commonly [1] meant hollow metal tubes used to transmit radio waves. This kind of waveguide is mainly used as the transmission line of microwave frequency. It is used to connect microwave transmitter and receiver with their antenna in microwave oven, radar, communication satellite and microwave radio link equipment.
The dielectric waveguide adopts solid dielectric rod instead of hollow tube. Optical fiber is a dielectric waveguide which works at optical frequency. Transmission lines such as microstrip, coplanar waveguide, stripline or coaxial cable can also be considered as waveguides.
The electromagnetic wave in the metal tube waveguide can be imagined to travel along the zigzag path in the waveguide and reflect back and forth between the walls of the waveguide. For the special case of rectangular waveguide, it can be based on the accurate analysis of this point of view. The propagation in the dielectric waveguide can also be viewed in the same way. The wave is limited in the interior of the dielectric by the total internal reflection of the dielectric surface. Some structures, such as non radiative dielectric waveguides and high protection lines, use metal walls and dielectric surfaces to limit waves.
1 standard circular waveguide
2标准扁波导
3标准方波导
4标准矩波导
5 矩波导B法兰
6矩波导D法兰
