Robust Microwave Characterization of Inkjet Printed Coplanar Waveguides on Flexible Substrates

摘要

In this paper, we propose a robust microwaveudcharacterization of inkjet printed components on flexible substrates,udwhich aim at measuring the material properties ofudsilver nanoparticle inks and the supporting dielectric spacerudemployed during measurements. Starting with propagation constantudextracted from multiline thru-reflect-line calibration withudcoplanar waveguide (CPW) standards and then proceeding withudfinite element modeling of CPWs, the proposed technique canuddynamically produce an interpolated search space by automaticuddriving of simulation tools. In the final stage, the algorithmudutilizes a least-square optimization routine to minimize theuddeviation between model and measurements. Our techniqueudsignificantly reduces the computing resources and is able toudextract the material parameters using even a nominal ink profile.udCharacteristic impedances for CPWs are extracted using seriesudresistor measurements from 10 MHz to 20 GHz. It is alsoudshown that the proposed characterization methodology is ableudto detect any changes in material properties induced by changes udin fabrication parameters such as sintering temperature. Inkudconductivities of approximately 2.973×10^7 S/m and spaceruddielectric constant of 1.78 were obtained for the inkjet printedudCPWs on PET. In addition, the inkjet printed CPWs sintered at ud170°C and 220°C on Kapton had conductivities of 0.187×10^7 and 0.201×10^7 S/m respectively. We verified our technique byudmeasuring the material parameters with conventional approach.