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Summarization: This article presents European-based contributions for wireless power transmission (WPT), related to applications ranging from future Internet of Things (IoT) and fifth-generation (5G) systems to high-power electric vehicle charging. The contributors are all members of a European consortium on WPT, COST Action IC1301. WPT is the driving technology that will enable the next stage in the current consumer electronics revolution, including batteryless sensors, passive RF identification (RFID), passive wireless sensors, the IoT, and machine-to-machine solutions. The article discusses the latest developments in research by some of the members of this group. Presented on: IEEE Microwave Magazine

This essay points out the perspective by which contemporary art’s development may be considered as some sort of mythical regression; in particular, the support given by Arthur Danto’s thinking to Andy Warhol’s poetics is identified as the paradigm of this regression, since the work of art and the common object become aesthetically indiscernible, but only the former possesses an artistic essence that the latter doesn’t. Likewise, the mythical concept of reality doesn’t consider things for what they really are and, nevertheless, it confers to some of them an intangible essence that eludes aesthetical perception. To solve this, it has been chosen to transpose into aesthetics’ field the reflections upon myth and mythology conceived by the gifted and versatile Italian scholar Furio Jesi., I castelli di Yale online, volume V, numero 2, 2017

In this presentation we discuss in details WPT systems solutions for potential space applications exploiting both near-field and far-field techniques. In particular a lightweight and low-power system, combining RF-ID and beam-forming technologies, is described in details able to selectively powering battery-less devices pervasively distributed in the ambient. This solution is presented as a feasible implementation of portable satellite environmental testing and monitoring, thus allowing sensors reading in locations difficult to access. Subsequently a contactless system for high-power transfer (of the order of kW) is proposed as a reliable wireless transition in rotating joints, to get rid of wires, for both power transmission and data communication. In both cases design issues and the adopted practical solutions are discussed based on a rigorous implementation of a circuit-level design of the entire system, combining nonlinear and electromagnetic simulation.

Described is a working unit (1) comprising a stationary part (2) and a movable part (3) and a movable working device (4) defining an electrical user device, powered by a stationary electricity supply (5A) through a first contactless electricity supply line (L1), defined by a rotary transformer; the working unit (1) also comprises a control element (12), movable as one with the working device (4) and designed to vary a relative electrical property as a function of a parameter relative to the working device (4); the control element (12) is powered, at least temporarily, independently from the electricity supply of the working device (4).

In this paper we describe a geometry design solution to minimize performance variations of a wireless power transfer system “on the move” (WPT-Mob). A sequence of switchable couples of coils, connected in series or in parallel, is adopted at the fixed transmitting link side; the geometry of the moving receiver is optimized to keep the coupling factor, and thus the power transfer, constant during the movement. First the analytical formulation of the link coupling factor is derived as a function of its circuit-equivalent parameters computed by full-wave simulation. Then selected geometry parameters of the receiver side are optimized to keep the coupling factor constant while the link is moving. A set of TX-RX arrangements are simultaneously analysed to emulate the sliding movement of the WPT-Mob. The final optimized geometry demonstrates that a constant power transfer on-the-move is enabled, even for variable TX-to-RX link distances. Design and experimental verification are carried out for a geometry suitable for medium power transfer (tens of Watts) at 6.78 MHz, but the method is formulated in such a way that the system can be scaled up and down to accomplish different application needs.

The idea of this paper is to develop a moving resonant wireless power transfer (WPT) system capable of keeping the coupling factor, and thus the power transfer, invariable with respect to the reciprocal system sides positions. A typical scenario is the WPT to moving objects on a platform equipped with a sequence of coils underneath. If a single TX coil is active at a time, the receiver movement would cause the coupling coefficient, and consequently the transmitted power, to oscillate. To cope with this problem, in this work we propose to make use of two active Tx coils. Different coil geometries and coil connections have been investigated, trying to get an insight into the coupling mechanism. This have been done by full-wave simulations and measurements of the selected structures and by varying some key parameters of the geometry itself. The connections between coils have been done in post-processing and the results have been plotted for comparison. Future work has been proposed.

This paper presents an innovative nonconventional exploitation of a self-resonant capacitive near-field link at UHF, for data communication, to be combined in a compact wireless power transfer (WPT) system. At UHF, an increased channel transfer efficiency is made possible by exploiting two faced auto-resonant structures, such as split-ring resonators (SRRs), one at each far-end side of the link. Their physical layouts are designed to ensure accurate prediction of both the resonant frequency and the resulting frequency-variable behavior of the two-port arrangement. This network is then used in a passive sensing system, based on a smart exploitation of the dc-power dc-load relationship of a standard RF identification (RFID) rectifier, to convert the data of a remote sensor, representing the system variable load. The reflected power variations at the transmitter side, due to the dc load variations, are successfully used to perform the sensor readout. The entire sensing system is first optimized by means of nonlinear circuit and electromagnetic (EM) simulations. Experimental data, compared to prior results, demonstrate the strength of the adopted approach.

An innovative system, which pairs an RFID-based passive sensor link with a ferrite-based power CET unit, is designed for a temperature-controlled heating system remotely located in a rotary machine tool. Capacitive and inductive coupling are integrated in a unique platform to implement the wireless data and power links, respectively. This ensures at the same time compactness and absence of cross coupling between data and power transfer. The rectifying part of a passive RFID tag is exploited to simultaneously power and read a Pt1000 temperature probe located in a inaccessible part of the rotary tool. The procedure to design layout-wise the system is described and an extensive experimental validation is discussed.

This paper is dedicated to the extensive review of state-of-the-art contactless energy transfer (CET) systems that are gaining increasing interest in the automatic machinery industries. We first introduce the circuit equivalent networks considered in the literature, and discuss the main operating principles. Possible circuital resonant solutions are also discussed together with the required compensating networks. Then we focus on the problem of transferring, at the maximum efficiency, high-power levels (of the order of 1 kW or higher), showing that highly coupled inductive links are needed, requiring to refrain from the resonance condition. These systems are usually referred to as CET systems, since the link distances are negligible with respect to the coils dimensions. The operating frequencies are of the order of tens to hundreds of kilohertz. The fundamental figures of merit are analytically defined and used to measure the actual limitations involved in this class of systems, including aspects related to realization feasibility with respect to voltages and currents limitations. Finally, state-of-the-art CET works are surveyed, and realistic applications for different operating frequencies are considered and critically compared.