Waveguide-to-microstrip power splitter

A novel coupling structure which permits both power combining and division is described. The structure divides power equally from a rectangular waveguide to two microstrip lines. The microstrips are T-shaped conductor patterns placed symmetrically in the waveguide. The splitter has a return loss of better than 20 dB from 3.3-4.6 GHz measured at the waveguide port. The power difference between the two microstrip output ports is less than 0.1 dB. The coupler is useful for power combining at microwave and millimeter-wave wavelengths with minimal power loss.<>