A waveguide filter is an electronic filter constructed with waveguide technology.

a type of electrical planar transmission line which can be fabricated using printed circuit board technology, and is used to convey microwave-frequency signals.

Arrayed waveguide gratings are commonly used as optical (de)multiplexers in wavelength division multiplexed systems.

A waveguide flange is a connector for joining sections of waveguide, and is essentially the same as a pipe flange—a waveguide, in the context of this article, being a hollow metal conduit for microwave energy.

An erbium-doped waveguide amplifier (or EDWA) is a type of an optical amplifier enhanced with erbium.