Wave-guide component is the basic functional part of microwave systems made of hollow metal wave-guide or cavity. Wave-guide components can form various wave-guide networks or be connected into various microwave communication. Their specs are similar to those of electric resistance, inductance, capacitance at different frequencies, wave-guide can serve to transmit microwave signals or power, and complete various functions such as waveform transformation, impedance adjustment, frequency separation or power distribution.

The working frequency of wave-guide components is generally in the microwave range, and wave-guide components generally have more than two ports. Wave-guide components control electromagnetic waves by some inhomogeneity or some coupling mechanism, that is, to carry out various transformations on electromagnetic waves. The main types are bent wave-guide and twisted wave-guide, soft wave-guide, impedance transformation element and wave-guide joint. Wave-guide devices mainly include wave-guide coupler, wave-guide filter, wave-guide combiner, wave-guide load, wave-guide attenuator, wave-guide adapter and so on.