Printing technologies for the manufacturing of passive microwave components: antennas

In this study, the application of printing technologies for the manufacturing of passive microwave components such as antennas is highlighted, and a detailed example is given. Common printing technologies such as inkjet, screen, and gravure printing become adjusted to print conductive inks for the manufacturing of printed antennas on flat substrates or even on three-dimensional (3D) surfaces. Especially, printing technologies such as pad printing, micro-jetting, dispensing, and aerosol jetting are candidates for the manufacturing of microwave components onto challenging 3D surfaces, which may facilitate new designs. Depending on the substrate, one technical challenge is to choose a proper metal ink in combination with a suitable thermal treatment to reach critical requirements such as electrical conductivity above 106 S/m or proper adhesion of the printed pattern for an antenna application. This study gives an overview and comparison of the state-of-the-art materials, inks, printing processes, and options of subsequent thermal treatment. The challenges and possibilities for printed-passive microwave components are discussed with regard to microwave applications. The development of a printed radio-frequency identification antenna on a 3D surface is demonstrated, and the performance of the manufactured antenna is discussed in detail.