Multilayer printing of embroidered RF circuits on polymer composites

This paper presents embroidered conductive fibers (E-fiber) on polymer composites for conformal and light-weight RF circuits and antennas. A polydimethylsiloxane, namely PDMS, is adapted. Our earlier studies showed that it had a remarkable RF performance with a tangent loss of less 0.02 at RF frequencies. In this paper, an embroidered E-fiber microstrip line sample was fabricated with conductive fibers on a polymer substrate, and its RF characteristics were measured. The S-parameters were compared with those of copper microstrip lines. Measurements indicated that the insertion loss of the E-fiber microstrip line was only 0.04dB/cm higher than that of the copper. A multilayer microstrip line using similar fabrication techniques was also printed and measurements were conducted. All results clearly demonstrate the feasibility of the proposed embroidered conductive fiber technique for flexible and conformal RF applications.