A fully-screen printed, multi-layer process for bendable mm-wave antennas

In the era of Internet of Things (IoT) and wearable electronics; printing technique, such as screen printing, is becoming popular because of their lower costs and mass manufacturing abilities. However, most of the previous work has been done on printing metallic patterns and not the printing substrates. In this paper, we introduce a custom screen printable dielectric ink (polymer mixed with ceramics), which provides lower loss even at millimeter-wave (mm-wave) bands. With the help of dielectric ink and custom silver nanowires (AgNW) based metallic ink, a multilayer, fully screen-printed fabrication process has been developed. To demonstrate the efficacy of the proposed inks and the multilayer printing process, a stacked patch antenna with 4-parasitic patches in the superstrate is designed, fabricated, and tested for the mm-wave band (5G band). Despite a new fabrication process, the measured results show a decent antenna performance (both in flat and bent positions) where the input impedance is matched from 26.5-30 GHz and a maximum gain of 7.8 dBi has been attained.