Microstrip to waveguide transition dedicated to wireless millimeter-wave applications

This paper propose a novel millimeter-wave microstrip (MSL) to WR 12 standard rectangular waveguide transition. These dissimilar structures are interconnected via a trapezoidal substrate integrated waveguide (TSIW). The MSL and the TSIW are integrated on the same ceramic substrate of 9.9 of permittivity and 125 of thickness. The MSL has been first transformed into an air-filled rectangular waveguide, and then a horn transformer has been used to match the WR12 waveguide. The central frequency of operation is 61 GHz and dedicated to V-band wireless communications applications. The S parameters measurements of the back-to-back connected transitions show an insertion loss less than 1.5 dB and a return loss better than -10 dB over a 5 GHz bandwidth from 60 to 65 GHz. The high performance and the compact size, enable the transition to be employed in a number of millimeter-wave applications.