Copper Transparent Antennas on Flexible Glass by Subtractive and Semi-Additive Fabrication for Automotive Applications

There has been an increasing need for antennas in automotive applications, for communications applications, such as cellular, satellite radio, and the burgeoning fields of selfdriving/ networked vehicles and 5G. These applications demand alternatives to traditional vehicle antennas, including transparent antennas able to be unobtrusively mounted to vehicle windows. Flexible glass provides a high quality transparent and flexible substrate for the fabrication of these antennas, and that is amenable to low cost roll-to-roll manufacturing. Sheet scale prototype transparent antennas were fabricated in copper using etch back and semi-additive processes, with conventional processes and facilities, and using materials and processes amenable to roll-to-roll fabrication. This shows that flexible glass could be used in existing lines and facilities with little modification, in addition to roll-to-roll processing. Fabricated antennas were tested on-vehicle and show good performance, with similar gain figures for baseline solid antennas, etched transparent antennas, and semi-additive transparent antennas.