What Does Waveguide Mean?
A waveguide is a structure that guides waves, such as electromagnetic waves or sound waves. The original and most common type of waveguide is a hollow conductive metal pipe used to carry high-frequency radio waves, particularly microwaves.
Waveguides are used in:
- Transmitting light, signals & powers
- Sound waves
- Transferring radio frequencies
They are also used in scientific instruments to measure optical, acoustic and elastic properties of materials and objects. Waveguides are the fundamental principle of guided wave testing (GWT), a method of non-destructive evaluation.
Corrosionpedia Explains Waveguide
A waveguide is a metal tube or other device used in confining and conveying waves. The geometry of a waveguide reflects its function as well as the frequency of the transmitted wave. Waves propagate in all directions in open space as spherical waves. A wave-guide confines the waves to propagate in one dimension, so that, under ideal conditions, the wave loses no power while propagating. The conductors generally used in waveguides have a shallow surface depth, and hence large surface resistance.
Different types of waveguides include:
- Electromagnetic waveguides - Constructed to carry waves over a wide portion of the electromagnetic spectrum, but are especially useful in the microwave and optical frequency ranges
- Optical waveguides - Used at optical frequencies, are typically dielectric waveguides, such as optical fiber or photonic-crystal fiber
- Acoustic waveguides - A physical structure for guiding sound waves, also behaves like a transmission line
Waveguides can be completely destroyed by electrolytic corrosion in a relatively short period of time if they are not isolated from direct contact with other metals. Any inspection of a waveguide system should include a detailed inspection of all support points to ensure that electrolytic corrosion is not taking place.
Corrosion at waveguide joints is a major problem area reported in US military fire control system (FCS) antenna assemblies. Due to inherent crevices, dissimilar metals, thermal cycling and direct exposure to a hostile and dynamic marine environment, waveguide flange connections are highly susceptible to severe and rapid corrosive attack. Moisture can be one of the worst enemies of a waveguide system. Any waveguide that is exposed to the weather should be painted and all joints sealed.