[IEEE 2020 IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes for RF and THz Applications (IMWS-AMP) - Suzhou, China (2020.7.29-2020.7.31)] 2020 IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes for RF and THz Applications (IMWS-AMP) - Extracting Complex PCB Substrate Permittivity from a Transmission Line using the Finite Difference Integral Method from 10 GHz - 100 GHz