Low-Loss Perpendicular Transition Between Rectangular Dielectric Waveguide and Microstrip Line at W -band

In this article, a low-loss perpendicular transition between a rectangular dielectric waveguide (RDW) and a microstrip line (ML) at W-band is proposed. The transition consists of a patch, a ridge waveguide (RW), a tapered RW, a dielectric-filled rectangular waveguide, and a tapered horn. The patch and the RW are coupled to reduce the insertion loss and expand the bandwidth of the transition. An equivalent circuit model of the transition is established and a synthesis method is applied for the design. The experimental results show that the frequency range ( $\vert S_{11}\vert \lt -10$ dB) of the RDW with two proposed transitions is from 80.9 to 108.6 GHz. In the frequency range, the insertion loss of the transition is from 0.42 to 1.72 dB. Compared with the previous perpendicular transitions, the proposed transition has the lowest insertion loss. It can be used for RDW-based interconnects.