A New Integrated Waveguide-Microstrip Transition

A new waveguide-microstrip transition is described. This design provides wide-band performance (18-26GHz) and a very good reproducibility without the need for variable elements. The circuit is fully integrated on the substrate and the characteristics are much less sensitive to small variations in the dimensions than other known transitions. A narrow-band version is made in particular for the telecommunication band (17.7 - 19.7GHz) with a VSWR less than 1.1 and an attenuation less than 0.25dB. The design can be easily scaled to other frequencies and is in particular useful at frequencies above 10GHz.