Directional coupler and a method of manufacturing thereof

A radio frequency waveguide network, wherein a directional coupler of the network has, in use,

• the open end of one waveguide portion configured to receive the electromagnetic signal,
• the other open end of the waveguide portion configured to output a first electromagnetic signal coupled to the electromagnetic signal,
• the further open end of the other waveguide portion arranged at the same side of the other open end configured to output a second electromagnetic signal coupled to the electromagnetic signal, and wherein
• the shape of the aperture is arranged to induce an absolute phase difference between the first electromagnetic signal and second electromagnetic signal of substantially 90 degrees.

A method of manufacturing a directional coupler, comprising

• providing two half solid bodies made of a selected material,
• removing the material from each half solid body for leaving one or more walls protruding from a cavity produced by the removed material, the one or more walls aligned along a longitudinal direction of the half body, the cavity extending from a first side of the half body to a second side of the half body opposite to the first side in the longitudinal direction, the cavity having an open side along the longitudinal direction of each half body, the two half solid bodies having equal cross sections perpendicular to the longitudinal direction,
• after removing the material, assembling the two half bodies along the open side such that the one or more walls of one half body are joining the one or more walls of the other half body on a single plane for forming two waveguide portions having a common wall between the two waveguide portions on a plane orthogonal to the single plane,
• at least one of the wall having a side edge having a slanted part with respect to the longitudinal direction for forming an aperture in the common wall, the aperture coupling the two waveguide portions and having a shape comprising a slanted part with respect to the longitudinal direction.