Flexible polyethylene terephthalate-based inkjet printed CPW-fed monopole antenna for 60 GHz ISM applications

This study investigates an inkjet-printed millimetre-wave antenna on Polyethylene Terephthalate (PET) substrate. The 60 GHz CPW-fed monopole antenna was 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 or printing. Then, silver lines are inkjet printed on the PET substrate, followed by curing in an oven to remove excess solvent and material impurities. The multiple-pass lines are printed to study the changes in surface roughness and line width. The silver film conductivity of the conductive ink is around 4×10⁶ S/m. The measured impedance bandwidth of the printed antenna, defined by return loss less than -10 dB, is from 60 to 65 GHz.