摘要 |
A waveguide coupler is provided with a trough portion with a first trough and a second trough. A coupling slot between the inner sidewalls of the first and second troughs communicates between the first trough and the second trough. A cover closes the first trough and the second trough to form first and second waveguides. The cover includes a protrusion surface with protrusions extending into the first trough and the second trough. The protrusions form a stepped ridge with a plurality of steps in height, if desired, lateral position. The steps are provided with a maximum inward extension and a minimum lateral distance from the coupling slot at a center step proximate a center of the coupling slot. The coupler is selectable between a high coupling level and a low coupling level by exchanging the cover applied to the trough portion between a flat surface and the protrusion surface. |