Broadband Stacked-Patch Transition from Microstrip Line to Circular Dielectric Waveguide for Dual-Polarized Applications at W-Band Frequencies

Transitions from planar waveguides like microstrip lines (MSL) to dielectric waveguides (DWGs) are a key component for high data rate interconnects using DWGs. Transitions that are able to excite both polarizations of the DWG's fundamental mode could theoretically double the data rate of such interconnects. The MSL-to-DWG transition presented in this paper allows such a dual-polarized excitation of the fundamental mode with highly reduced complexity compared to already existing transitions. The transition is realized as a stacked patch topology where the upper patch is included into the dielectric waveguide attached perpendicularly to a printed circuit board (PCB). The stacked patch topology allows a broadband transmission into the DWG with a single layer PCB layout and low space requirement. A dielectric stamp at the bottom of the dielectric waveguide increases the efficiency of the transition without the need for additional metallic waveguide structures. A measured insertion loss for both polarizations of lower than 1.8 dB over a bandwidth of 16GHz at W-band frequencies is achieved.