Waveguides are usually fixed/rigid (with the exception of flexible waveguides) and therefore need bends to allign the waveguide in to a particular position. The correct bend is extreamly importnat, as this regulates the loss and reflections in the system. There are two main kinds of waveguide bends:
E Plane: This type of bend changes the electric field to enable the waveguide to be bent in the required direction. The bend must have a radius greater than two wavelengths.
H Plane: This type of bend changes the magnetic field. It creates a bend around the thinner side of the waveguide. This also must have a radius greater than two times the wavelength.
The Unknown Editor from Microwaves 101 has a great way to identify the Waveguide E & H Planes. He says the E-plane is starts with an E and the H plane starts with and H - which you can see in the photo below.
In addition to this the frequency, waveguide size, bend angle and VSWR are also important parameters which are used when selecting a waveguide bend.
everything RF has listed the leading manufacturers for Waveguide Bends. Download datasheets, see product specifications and get quotations on the products you need.
We have listed the leading manufacturers of waveguide bends here, in case you feel we have missed some manufacturers, let us know.