Novel F-Band, D-Band SiC Substrate-Integrated Waveguide Passive Components with Application in Active Circuits for 6G and Beyond

F-band substrate-integrated waveguides (SIWs) are designed, fabricated, and characterized on a SiC wafer, along with SIW-based filters, impedance standards, and transitions to grounded coplanar waveguides (GCPW). These results show the feasibility for monolithic integration of high-quality filters with high-efficiency antennas and amplifiers in a single-chip RF front-end above 110GHz, which is particularly advantageous for 6G wireless communications and next-generation automobile radars. Meanwhile, a report of a distributed amplifier (DA) realized through monolithic integration of transistors with a substrate-integrated waveguide (SIW) is discussed. The DA uses a stepped-impedance microstrip line as the input divider like in conventional DAs, but uses a low-loss, high-power-capacity SIW as the output combiner. This proof-of-principle demonstration opens the path to improving the gain, power and efficiency of DAs with higher-performance transistors and drive circuits. Although the demonstration is through monolithic integration, the approach is applicable to heterogeneous integration with the SIW and transistors fabricated on separate chips.