Characterization of ink-jet printed CPW on Kapton substrates at 60 GHz

This paper characterizes coplanar waveguide (CPW) lines formed by ink-jet printed conductors on flexible Kapton substrates at frequencies up to 60 GHz. It is shown that the lines have losses of approximately 1.5 dB/mm but that this relatively high loss is predominantly due to the loss tangent of the substrates and not the lower conductivity of the silver inks used in this implementation. On an Alumina sample the loss is shown to be 0.8 dB/mm for the same ink-jet printed lines. CST simulation has been used to verify the calculated results.