An inkjet-deposited antenna for 2.4 GHz applications

Printed electronics is a promising technology that has received tremendous interest as a mass production process for low-cost electronics devices, because it increases manufacturing flexibility and decreases manufacturing costs. The low process temperatures allow the use of flexible substrate materials, such as paper or plastics, suitable for a reel-to-reel process. In this paper we focus on high-frequency properties of printed electronics. We designed and manufactured a transmission line and a patch antenna for 2.4 GHz ISM band. One test set was manufactured using conventional etching technique for a reference with a metal thickness of 17μm. Two other test cases were fabricated using an inkjet-based printing technique that is described in more detail later in this paper. Printed patterns have thicknesses of 2.5 and 0.5μm. This work evaluates the suitability of printed electronics in high-frequency applications. Insertion loss in the 60 mm-length transmission line was 0.1 dB higher in the case of the printed (thick) line than in that of the etched line. Furthermore, impedance matching bandwidth was almost the same in all antennas, although a small decrease in radiation properties was found.