Modeling and synthesis of multiport transmission line for multichannel communication

To overcome the limitations of traditional interconnects, multichannel interconnects that transmit signals via high-frequency carriers have recently been proposed and realized for intrachip and interchip communication. To efficiently design such transmission-line-based interconnects, this paper derives a closed-form model for signal-to-noise ratio (SNR) considering multiple ports and branches, and proposes efficient figures of merit (FOMs) to minimize signal distortion. Experiments show that the SNR model is accurate compared to SPICE simulation and the signal distortion FOMs are effective. Using the proposed models, this paper further automatically synthesizes coplanar waveguides (CPWs) for radio-frequency (RF) interconnects with capacitive couplers. The authors minimize the total interconnect area under the constraints of SNR and signal distortion. Compared to the published manual designs, the synthesized solutions can reduce up to 80% area. Furthermore, the optimized solutions vary greatly with respect to number of ports, frequency bands, topologies, and terminations, and therefore automatic synthesis is effective and necessary