Antenna and Array Technologies for Future Wireless Ecosystems

4Smart Leaky‐Wave Antennas for Iridescent IoT Wireless Networks

José L. Gómez‐Tornero

Technical University of Cartagena, Department of Information and Communication Technologies, Telecommunication Faculty, Cartagena, Spain

4.1 Leaky‐Wave Antennas for Efficient Wireless Systems

Most advanced wireless mobile communications systems depend on adaptive “smart” antennas to provide maximum range and data rate [1–3]. Unfortunately, those smart antennas tend to be complex, costly, and power hungry compared with passive antennas. Therefore, smart adaptive antennas have not been widely used in mobile terminals and Internet of things (IoT) devices.

Leaky‐wave antennas (LWAs) are a type of traveling‐wave antenna that can produce directive scanning beams using a single feed [4]. Compared with phased‐array antennas, they avoid the use of complex feeding networks and electronically tunable components to provide high‐gain scannable radiation patterns. The directive beam of an LWA can be steered by simply changing the operation frequency. Since LWAs are strongly dispersive, they have the inherent property of being directive frequency‐beam scanning. This is illustrated in Figure 4.1a, where the configuration of an LWA of length L and fed from a single port is depicted. As shown in Figure 4.1a, a directive beam is created, pointing at a scan angle θ_R measured from its perpendicular direction, and with a given half‐power beamwidth (HPBW) Δθ. The radiated‐beam characteristics depend on the dispersion ...