Fabrication of electromagnetic waves absorbing material by ink-jet printing method

Fabrication of microstrip transmission line (MTL) in a one-step and direct process was a challenge in many of the recent research projects. In this study, for the first time, an MTL is printed on RO4003C substrate using water-based reactive inks and ink-jet printing technique. The deposited MTL structure includes an ink-jet printed silver line, a dielectric layer, and a continuous metallic ground plate. The conductivity of the printed MTL is measured using four-point probe method. Experimental results showed that the absorption rate of MTL at the 1-5 GHz frequency range is close to 70% revealing a good agreement with the results obtained from the software simulation. Increasing the conductivity of the deposited layer up to 1950 S/m will increase the electromagnetic (EM) absorbing power, while increasing conductivity after this maximum causes a constant decrease in the absorption rate. Fabricating a layer with the conductivity close to the bulk silver can ultimately reduce the absorption rate close to zero where the product will be suitable for use as an interconnection in EM wave handling circuits.