The realization of a programmable metasurface, enabled by a custom application-specific integrated circuit (ASIC), is presented in this paper. The ASIC is used to provide an adaptive complex impedance load to each of the metasurface unit cells. Various technology nodes are analyzed for the implementation of tunable complex impedance loading elements before one is selected for the final implementation, in which four complex loads are placed within each integrated circuit, and each load is controlled by two digital-toanalog converters. Furthermore, the ASICs populate the back of the metasurface to form a mesh network to enable programmability. The paper includes practical limitations that affect the realization, as well as an example adaptive metasurface absorber that builds upon the practical tuning range of the ASIC. Perfect absorption for both transverse electric and transverse magnetic polarization is demonstrated. INDEX TERMS Metasurfaces, ASIC, programmable RF load, perfect absorption, reconfigurable.

Manessis, D.; Seckel, M.; Liu, Fu; Tsilipakos, O.; Pitilakis, A.; Tasolamprou, A.; Kossifos, K.; Varnava, G.; Liaskos, C.; Kafesaki, M.; Soukoulis, C. M.; Tretiakov, Sergei; Georgiou, J.; Ostmann, A.; Aschenbrenner, R.; Schneider-Ramelow, M.; Lang, K. D.High frequency substrate technologies for the realisation of software programmable metasurfaces on pcb hardware platforms with integrated controller nodes AbstractThe proposed work is performed in the framework of the FET-% 8:72-+< D&# "#%"E ?01+0 has undertaken research activities on the emerging concepts of metamaterials that can be software programmable and adapt their properties. In the realm of electromagnetism (EM), the field of metasurfaces (MSF) has reached significant breakthroughs in correlating the micro-or nano-structure of artificial planar materials to their end properties. MSFs exhibit physical properties not found in nature, such as negative or smaller-than-unity refraction index, allowing for EM cloaking of objects, reflection cancellation from a given surface and EM energy concentration in as-tight-as-possible spaces.The VISORSURF main objective is the development of a hardware platform, the Hypersurface, whose electromagnetic behavior can be defined programmatically. The key enablers for this are the metasurfaces whose electromagnetic properties depend on their internal structure. The Hypersurface hardware platform will be a 4-layer build-up of high frequency PCB substrate materials and will merge the metasurfaces with custom electronic controller nodes at the bottom of the PCB hardware platform. These electronic controllers build a nanonetwork which receives external programmatic commands and alters the metasurface structure, yielding a desired electromagnetic behavior for the Hypersurface platform. This paper will elaborate on how large scale PCB technologies are deployed for the economical manufacturing of the 4-layer Hypersurface PCB hardware platform w1<0 ) ;1B-7. E@E, having copper metasurface patches on the top of the board and the electronic controllers as 2mmx2mm WLCSP chips at 400µm pitch assembled at the bottom of the platform. The PCB platform designs have stemmed from EM modeling iterations of the whole stack of high frequency laminates taking into account also the electronic features of the controller nodes. The manufacturing processes for the realization of the selected PCB architectures will be discussed in detail.

No abstract

Uterine contractility is known to play significant role in women's health. Ultrasonography and magnetic resonance imaging have been used for assessing uterine peristalsis, however they lack practicality, objectivity, and costeffectiveness. In this paper, the ElectroUteroGraph (EUG) and novel electrodes are introduced, to cover the unmet need of practical intrauterine contractility assessment. The EUG measures biopotentials produced by uterine muscle contraction, similar to the basis of electrocardiography. Methods: The EUG was used to fifteen healthy, non-pregnant women of reproductive age. Amplitude and frequency-related features were derived from our recordings. Results: The EUG and novel electrodes did not cause any pain or discomfort to the patients, over their multiple recording sessions. The collected data showed difference between the proliferative and luteal phase of menstrual cycle (p < 0.05). Conclusions: The EUG can accurately measure uterine electrical activity, in a simple, standardized, safe and pain-free approach, leading to objective evaluation of uterine peristalsis.

No abstract