Using an inkjet printing process, it is possible to fabricate low-cost organic substrates that will serve devices requiring smaller and lighter-weight components. Furthermore, the inkjet printing of metallic nanoparticles also has allowed the production of flexible devices. Although antennas have been printed, they have been both low gain and narrow band, as they typically served the RF-identification (RFID) market. At Saudi Arabia’s King Abdullah University of Science and Technology, Benjamin S. Cook and Atif Shamim have conjured a fully characterized inkjet printing process that can be used to fabricate low-cost, paper-based, high-gain, and ultrawideband (UWB) antennas.
The partners characterized the inkjet printing process using metallic nanoparticle inks on a paper substrate for frequencies to 12.5 GHz. By comparing laser versus heat sintering of the metallic nanoparticles, they also demonstrated the cost and time benefits of laser sintering. The laser-sintering technique, which was characterized on paper, allows for quicker sintering with little to no substrate heating and lower energy requirements.
Among the antennas fabricated using the inkjet-printing process were a UWB Vivaldi antenna, which exhibited gain of 8 dBi—thereby achieving higher gain than currently produced inkjet-printed antennas. In addition, a slow-wave log-periodic dipole array leveraged a new miniaturization technique to show 20% width reduction. See “Inkjet Printing of Novel Wideband and High Gain Antennas on Low-Cost Paper Substrate,” IEEE Transactions On Antennas And Propagation, Sept. 2012, p. 4148.