Title: Smart Beaming of RFID Reader for Data and Power Transfer
DEI- University of Bologna
Nowadays there is an almost unlimited number of monitoring applications, such as structural health, logistic, security, healthcare and agriculture, which are planning to be based on a large deployment of co-operative wireless microsystems, with sensing capabilities, moving closer to the effective realization of the paradigm of the Internet of Things.
The main open challenge of these scenarios will be discussed, being the reliability of maintenance-free devices, with life-time duration, especially from the energy sustainability point of view. Such systems are required to power themselves, by harvesting energy from the ambient, thus eliminating battery needs. RF/microwave energy sources are foreseen as one of the best candidates to comply with energy autonomy, either because they are widely distributed in humanized environments or because they can be efficiently provided on demand. These two different ways of providing RF energy can be referred to as RF energy harvesting (EH) and wireless power transmission (WPT), respectively.
A solution to optimize (minimize) intentional WPT at UHFis proposed by adopting smart beaming techniques at the RFID reader side, with the twofold goal of locating the tag and then of providing on demand the needed RF energy in that precise direction. A dynamic radiating system based on the implementation of Time Modulated Array (TMA) is foreseen to be a very promising solution for the above-mentioned operation. It is noteworthy that, despite their agility, TMAs have a much simpler architecture if compared to other beam-forming solutions, such as phased arrays or retro-directive arrays. Indeed, the desired phase condition at the antennas ports is reached with no need for phase shifters, thus drastically simplifying the design and the realization phases. By a two-step real-time beaming implementation of linear TMAs, a smart WPT system is demonstrated: In the first step, the TMA is configured in such a way that the control sequences are designed to allow to get the position of the devices to be energized; such positions are used in the second operative step of the system, to set the time control modulating signals of the entire array for real-time beaming the RF power to the wanted directions. The dynamic nature of TMAs thus allows creating an agile energy-aware reader/transmitter to be adopted in different scenarios, pervasively occupied by batteryless devices. The procedure allows a flexible design of the TMA-based WPT system, taking into account the impact of different array elements layout and spacing on localization and power transmission performance. Theoretical justification and experimental verification are presented and discussed.
Alessandra Costanzo (M’99-SM’13) received the laurea-degree with honor in Electronic Engineering from the University of Bologna, Italy, in 1987. Thereafter she joined the University of Bologna as a research associate and she became associate professor in 2001. She has been teaching courses in Electromagnetic Field Theory, Microwaves, Nonlinear Microwave Circuit Design, Numerical Techniques for Electromagnetics and Bioelectromagnetics. She is and has been supervisor of many MS and BS students and tutor of several Ph.D. students.
Her research activities have been dedicated to the development of CAD algorithms for multi-domain co-design and modeling of active nonlinear microwave/RF circuits. These approaches have been extended to the efficient circuit-level design of entire wireless links, including rigorous models of the radiating elements and of the propagation channels. She has carried out designs of MIMO, UWB and RFID systems and of highly innovative multi-band rectennas, specialized for wearable applications. She is now involved in multiple research activities related to the wireless power transmission technologies, adopting both far-field and near-field solutions, for several power needs, operating frequencies and application scenarios, namely powering of energy autonomous sensor nodes and charging of portable devices. She has developed innovative sensing solutions, based on EM interference, for non-invasive structural monitoring. She authored more than 180 scientific publications on peer reviewed international journals and conferences, and several chapter books. All these activities have been carried out in the framework of international research projects and/or in collaboration with private companies. She owns three international patents. Dr. Costanzo is being serving in several committees of the IEEE Microwave Theory and Techniques Society (IEEE MTT-S). She is member of MTT-S technical committees MTT-24 (RFID) and of MTT-26 (Wireless Energy Transfer and Conversion), where she is now serving as the chair. She is AdCOM member of the CRFID, representing MTT-S and chair of the steering committee of the new IEEE Journal of RFID. She is associate editor of the IEEE Transaction on MTT, of the Cambridge Journal of Wireless Power Transmission and of the International Journal of Microwave and Wireless Technologies. She is member of several technical program committees including the IEEE MTT-S International Microwave Symposium (IMS), the European Microwave Conference (EuMC), the IEEE Wireless Power Transmission Conference (WPTC), the IEEE International Conference of UWB and the IEEE RFID-TA. She was workshops chair and focus sessions chair for the EuMC2014, where she also organized the IEEE Women in Microwaves event (WIM). She is co-founder of the EU COST action IC1301 WiPE “Wireless power transfer for sustainable electronics” where she chairs WG1: “far-field wireless power transfer”.