Millimetre-wave flexible wearable antenna design and challenges for 5G and beyond

In this chapter, a Ka-band flexible antenna design is presented to address the 5G demands, and fabricated by two advanced methods of laser prototyping and inkjet printing for the comparative performance analysis. Post -printing process, i.e. heat sintering of the inkjet-printed prototype, is usually time-consuming, which has been significantly improved by proposing a novel method in this chapter to utilize a heat press instead of the oven to efficiently reduce the sintering duration from several minutes to just a few seconds. The antenna design is extended further in an antenna array for the gain enhancement. The antenna array proposed in this chapter is a potential candidate for the 5G flexible wireless devices due to its high performance attributes of gain and bandwidth, conformity and ease of integration, as well as safer to human body interactions because of lower penetration characteristics of mmWaves. Chapter Contents: • 9.1 Millimetre-wave spectrum for 5G networks • 9.2 High-frequency spectrum challenges for 5G • 9.3 Antennas for 5G cellular networks • 9.4 5G antennas interaction with human body • 9.5 Flexible antennas for 5G wearable applications • 9.6 Fabrication processes for flexible antennas • 9.6.1 Laser milling and PCB prototyping • 9.6.2 Inkjet printing • 9.6.3 Photolithography • 9.6.4 Screen printing • 9.7 Design and implementation of flexible 5G antenna • 9.7.1 Antenna design and fabrication • 9.7.2 Numerical and experimental analysis • 9.7.2.1 Radiation pattern • 9.7.2.2 Impedance bandwidth • 9.7.2.3 Realized gain • 9.8 Conclusion • References.