Fabrication of a planar spiral antenna using direct writing technology

Radio frequency identification (RFID) is a non-contact automatic identification technology that allows transmission of information and power via radio frequency signals. It has advantages including a short recognition distance, favorable efficiency, and reliable security. Planar antennas are an important aspect of RFID tags, and are usually manufactured by winding, screen-printing, and etching methods. These production processes typically involve thermal/mechanical stresses, chemical corrosion and other manufacturing processes which restrict the choice of substrate. On the other hand, direct writing technology provides a number of advantages, including no restrictions on the substrate, reduced costs, and simplified manufacturing processes. Because of these advantages, we propose a fabrication process for a spiral antenna using direct writing technology of a conductive material. The direct writing system was developed using a dispensing system and a 3-axis stage system. Consequently, a planar spiral antenna for an NFC tag was fabricated. The inductance of the fabricated spiral antenna was in good agreement with the designed value.