Broadband Microwave Absorber by direct drawing Metamaterial on Paper

A new way of fabricating microwave absorber utilizing conductive ink pen, pencil, paper and drawing machine is presented in the paper. Firstly a microwave absorber using double-square-loop array metamaterial structure with resistors loaded is designed based on equivalent circuit method. Then a conductive ink pen and a mechanical pencil is controlled by a drawing machine to draw metallic square loops and resistors onto the paper, respectively. It is shown through measurements that the the fabricated sample achieves 90% absorptivity ranging from 1.9 to 5.8 GHz (fractional bandwidth of 100.4%) which coincides with the simulation results. The operating bandwidth under oblique incidence is not less than the one in normal incidence until the incident angle up to 30 degrees. Comparing with microwave absorbers fabricated by traditional technics, this absorber is lighter, cheaper, more easy to fabricate and environmentally friendly.