A multilayer structure using a non-woven substrate treated with a waterborne polyurethane binder and various carbon-based and metal oxide additives has been developed by SP2 Carbon. This multilayer structure has been analyzed by an electromagnetic interference (EMI) high-frequency dielectric material measurement technique developed at NTNU to have excellent EMI shielding effectiveness above 10 – 15 GHz, where the absorption is almost 100%. This work offers a new way for the preparation of flexible polymer-based EMI shielding composite films for applications in 5G (& B5G) communication technology, wearable electronic devices, low-orbit satellites, and artificial intelligence.