Chapter 20 Comparative Study of Wireless Power Transfer and Its Future Prospective Amit Kumar Baghel, Chinmaya Behera, Shankar Amalraj, Ajit Singh, and Sisir Kumar Nayak 1 Introduction Wireless power transfer (WPT) is the method to transfer power from the source to load without the use of wires or cables. There are different ways of WPT which can be classified broadly into radiative and non-radiative WPT, as shown in Fig. 1. Radiative WPT is in which the antenna radiates electromagnetic wave where electric and magnetic fields are orthogonal to each other and related by free-space wave impedance, i.e., H = E η (1) where H is the time and space varying magnetic field, E is the time and space varying electric field, and η is the free space impedance ≈ 377 . The broad category of radiative WPT is microwave whose working frequency is in GHz and light waves or laser having a working frequency in THz. In non-radiative WPT, the transfer of power is basically through magnetic coupling of the transmitter and receiver coils where the maximum power transfer happens at a particular resonant frequency. Inductive and resonant inductive coupling are the two broad categories of A. K. Baghel (B ) · C. Behera · S. Amalraj Electronics and Electrical Engineering Department, IIT Guwahati, Guwahati, India A. Singh Electronics Engineering, Deen Dayal Upadhyaya College, New Delhi, India S. K. Nayak EEE Department, IIT Guwahati, Guwahati, India e-mail: sknayak@iitg.ac.in © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022 S. Dawn et al. (eds.), Smart and Intelligent Systems, Algorithms for Intelligent Systems, https://doi.org/10.1007/978-981-16-2109-3_20 219