Design a Transition between DML and SIW

Abstract

A novel dielectric transmission line, the dielectric microstrip line (DML), was proposed in millimeter-wave (mmW) and THz band recently. The DML gets rid of the conductor loss, which can be widely used in mmW and THz band for its low loss and easy fabrication. To apply the DML in active circuits, a good transition from the DML to other metal transmission line is necessary. A transition between the three-layered DML and the substrate integrated waveguide (SIW) over the frequency band of 54-61 GHz is presented in this project for the first time. A Yagi-antenna-liked structure is applied in the transition to couple the electromagnetic energy from the DML to the SIW. The transition is realized using the PCB technology. For testing the back-to-back transition from the DML to the SIW, a transition between the SIW to the rectangular waveguide (WR15) was also designed. A fixture fabricated using the 3D-printing technology is used to increase the stability of the measuring environment in consideration of the strict tolerance requirement in mmW band. The measured insertion loss of transition from the DML to the SIW ranges from 1.2 to 2 dB over 54-61 GHz, which generally matched with the simulated result.