Flexible plastic substrate-based inkjet printed CPW resonators for 60 GHz ISM applications

This study investigates inkjet-printed millimetre-wave coplanar waveguide (CPW) series tuning stubs printed on flexible plastic substrates such as Polyethylene Terephthalate (PET). These CPW resonators exhibit a bandpass/bandstop response that is useful for microwave and millimetre-wave filtering applications. The 60GHz CPW resonators were printed with a DMP-2800 series inkjet printing system. A silver nanoparticle colloidal solution was used as the printing ink. First, this process uses a plasma polymerization technique to improve the PET surface for printing. Next, silver lines are inkjet printed on the PET substrate and cured in an oven to remove excess solvent and material impurities. The experimental prototypes presented in this paper demonstrate the efficiency of the design method and the feasibility of creating CPW resonators using inkjet printing technology.