Electromagnetic Modeling Of Coupled Transmission Lines For Millimeter-Wave/Terahertz Circuits In 65 Nm Cmos Technology
Abstract
This work assesses the operation of differential transmission lines between 100 GHz and 200 GHz in a 65 nm CMOS process. The focus of this research is the impact of line dimensions and frequency on the odd-mode operation of coupled transmission lines. The research serves to identify a set of lines and line dimensions with high characteristic impedance, low loss, and minimal delay times. The following four coupled transmission line structures are assessed: coplanar waveguides, coplanar waveguides with a metal 1 ground layer, coplanar microstrips, and coplanar microstrips with a metal 1 ground plane. Simulation results from Sonnet and Cadence are presented. With these simulation results, overall trends of the losses, characteristic impedance, and delay of the lines are assessed. The results of this work yield a set of differential transmission lines with at least fifty ohm characteristic impedance, less than 1 decibel of loss, and propagation delay low enough to sustain a 100 - 200 GHz signal.