A waveguide interface comprising a support block configured to support a printed circuit board assembly. An interface is coupled to an end portion of the support block and extends from the support block. The interface includes a slot positioned to receive at least a portion of the printed circuit board assembly and one or more holes positioned to receive attachment devices to secure the interface to a waveguide component. The support block and interface are molded as a monolithic device. A method of forming the waveguide interface, a waveguide assembly including the waveguide interface, and a method of making the waveguide assembly including the waveguide interface are also disclosed.