Design of Wireless Power and Information Transfer Systems Considering Figure of Merit for Information

Abstract

Inductively coupled resonant wireless power transfer (WPT) systems can be used as a wireless power and information transfer (WPIT) system by properly adding the function of varying Rx loads. A new metric for the figure of merit for information transfer from Rx to Tx is proposed as the ratio of Tx input impedances for the Rx shorted and optimum loads to systematically assess the information transfer. While most of WPT and near-field communication (NFC) devices have been adopted for very short distances between Tx and Rx, this work shows that the WPIT systems using inductively coupled resonant structures with high Q-factor coils enable much longer working distances with the best power transfer efficiency and information transfer capability. Several design examples show that the newly proposed figure of merit for information transfer is an essential metric in the understanding and design of WPIT systems. The theory is validated with circuit and electromagnetic simulations for various system configurations.

Analysis of Received Power in RF Wireless Power Transfer System With Array Antennas

“…In (1), k is the wave-number and β m denotes the excited phase of the m-th Tx element. e −j(kRn,m−βm) shows the phase of the electric field according to the distance (R n,m ) and initial phase (β m ).…”

“…W IRELESS power transfer (WPT) technology has been used recently in various applications, such as mobile devices, wearable devices, implantable medical devices, and electrical vehicles. However, most of these applications adapt stationary wireless charging methods based on inductive coupling or resonant coupling [1], [2], meaning that there remains some inconvenience for users. On the other hand, radio-frequency (RF) WPT, sometimes referred to as microwave power transmission (MPT), can transfer wireless energy to a receiver (Rx) over a long and wide range.…”

Limiting magnetic exposures using ferrite core and shielding in wireless charging of mobile phones

“…17 The combined use of wireless information and energy transfer is very common in mobile device applications. 18 Shielding designs have been made to prevent leakage EMF generated during wireless charging of mobile phones. 19 The magnetic field concentration of the WPT systems was made using ferromagnetic material.…”

“…The WPT system was also combined with solar technology, thus charging a mobile phone with solar power using inductive coupling 17 . The combined use of wireless information and energy transfer is very common in mobile device applications 18 . Shielding designs have been made to prevent leakage EMF generated during wireless charging of mobile phones 19 .…”

Design of Moiré-Inspired Metasurface Lens for Focusing Electromagnetic Power in Fresnel Near-Field Region

“…Over the past decade, beam-focusing technologies in the Fresnel near-field region have been dramatically developed for various applications such as biosensing, radio wave therapy, wireless power transmission (WPT), and RFID [1][2][3][4][5]. In general, to focus the electromagnetic power of the beam in the near-field region, a WPT system is designed by using numerous array antenna elements or a large aperture antenna.…”