@ARTICLE{Steckiewicz_Adam_Reconfigurable_Early,
 author={Steckiewicz, Adam and Stypułkowska, Aneta},
 journal={Bulletin of the Polish Academy of Sciences Technical Sciences},
 pages={e149169},
 howpublished={online},
 year={Early Access},
 abstract={The paper presents a metamaterial with the reconfigurable effective properties, intended to operate in alternating magnetic fields. The structure of a resonator, based on a series connection of a planar inductor and a lumped capacitor, is expanded using an additional capacitor with a MOSFET transistor. Due to the presence of the controllable active element, it is possible to dynamically change the phase of a current flowing through a meta-cell and shift a frequency response within an assumed range. Since the transistor is driven by the unipolar square wave with a changeable duty cycle and time delay, two closed-loop controllers were utilized to achieve a smart material, able to automatically attain and maintain the imposed resonant frequency. As a result, the complex effective magnetic permeability of the metamaterial can be smoothly changed, during its operation, via an electrical signal, that is, by adjusting the parameters of a control signal of the active element. The design of the meta-cell, as well as the measuring, data operation and control part, are presented in detail. An illustrative system is examined in terms of achieving the user-defined resonance point of the metamaterial. The transient responses with estimated settling times and steady-state errors and the effective permeability characteristics for the exemplary cases are shown. The meta-cell is also tested experimentally to validate the theoretically determined effective properties.},
 type={Article},
 title={Reconfigurable smart metamaterial for energy transfer control in alternating magnetic fields},
 URL={http://www.journals.pan.pl/Content/130115/PDF/BPASTS-04293-EA.pdf},
 keywords={metamaterial, magnetic field, PID controller, smart material, resonance},
}