**7. Wearable Metamaterial antennas for 5G, IoT, and medical applications**

Low profile efficient antennas are crucial in the development of commercial compact 5G communication and IoT systems. Communication, IoT, and biomedical industries are in rapid growth in the last years. It is important to develop efficient high gain compact antennas for 5G communication and IoT systems. Metamaterials and fractal structures may be used to improve the efficiency of compact printed antennas. In this chapter metamaterial antennas will be presented.

#### **7.1 Introduction**

Small printed antennas suffer from low efficiency. Metamaterial technology is used to design wearable compact antennas with high efficiency. The metamaterial antennas may be used in 5G communication systems, IoT, and medical systems. Design trade-offs, development, and computed and measured results of compact, efficient metamaterial antennas are presented in this chapter. The gain and directivity of the patch antenna with split ring resonators (SRRs) are higher by 2.5 dB than the patch antenna without SRR. The resonant frequency of the antenna with SRR on human body is shifted by 3%. Printed antennas are used in communication systems and are presented in journals and books, as referred in [1–5]. Microstrip and printed antennas have several advantages such as being light weight, compact, flexible, and having low production cost. The main disadvantages of these printed antennas are narrow bandwidth and low efficiency. In Ref. [51], artificial media with negative dielectric permittivity were presented. Materials with dielectric constant and permeability less than 1 are developed by using periodic SRR and metallic posts structures as presented in [51–59]. New wearable printed metamaterial antennas with high efficiency are presented in this chapter.
