200 GHz-band Low-loss Half-Mode SIW CMOS Interconnects and Transmission Lines for Sub-Terahertz Frequency Band Applications

Low-loss half-mode substrate integrated waveguide (HMSIW)-based interconnects and transmission lines are designed and implemented in Complementary Metal-Oxide Semiconductor (CMOS) technology. In HMSIW interconnects, complementary split ring resonators (CSRR) whose self-resonance is much higher than the cut-off frequency of the SIW are etched on, due to which matching is improved. By controlling the parameters of the CSRRs, the losses due to microstrip to SIW transition are substantially improved, and no extra external matching circuit is required. A prototype was fabricated in 1P6M CMOS technology and tested. The measured cut-off frequency of the proposed HMSIW transmission line is 110 GHz, and the measured attenuation constant at frequencies of 175–220 GHz is less than 1.4 dB/mm. This work confirms a significant performance improvement of the CMOS interconnects in the sub-terahertz frequency band.