In this work we introduce a novel near-field focusing plate able to provide sub-wavelength focusing in both directions, parallel to the plate, as well as for both polarizations of the illuminating plane wave at microwave frequencies. Two similar designs are proposed: the first one is made of a thick metallic plate, whereas the second one is made of a thin copper plate fabricated on top of a Rogers 5880 dielectric substrate. The focusing behavior of these structures is analyzed with Ansys HFSS and CST Microwave Studio full-wave simulators. © 2011 IEEE.

In this paper a Fabry-Perot cavity (FPC) has been used to design a 60 GHz single feed directive antenna. The FPC antenna is made by a ground plane covered by a frequency selective surface (FSS). We have provided simple design guidelines based on a transmission line model. Numerical simulations confirm the design guidelines and antenna performances. ©2009 IEEE.

A low-loss planar Fabry-Pérot cavity antenna fed by a planar feed, a CPW-fed slot dipole, is designed and fabricated for 60 GHz wireless systems. The antenna is fabricated on a planar substrate using standard lithography process. The measurement results of the fabricated antenna are in good agreement with simulation data and show a gain of 16.5 dB. © 2012 IEEE.

In this paper, a prototype Fabry-Perot Cavity (FPC) antenna is designed and fabricated at millimeter-wave frequencies, aiming at designing directive antennas for 60 GHz wireless systems. A prototype FPC antenna is designed to have 17 dB gain at 42.8 GHz with 600-700 MHz 3dB-pattern-bandwidth and it is designed in order to be mounted on a wafer (chip). Measurement tools at millimeter frequencies and also antenna integration possibilities lead us to design an efficient feeding network for this kind of antenna. The antenna is fabricated on a quartz wafer (very low loss dielectric especially at millimeter-wave frequencies) which is coated by a thin layer of gold on each side. All the simulations on the reflection coefficient, gain and the radiation pattern of the antenna are done and compared using two most powerful EM simulators, Ansoft HFSS and Zeland IE3D and they are also compared with some measurement results for the prototype antenna. © 2010 IEEE.

In this paper, we show a wideband transmission line (TL) model for a Fabry-Perot cavity (FPC) antenna which is designed at a center frequency of 63 GHz using a thick and slotted metallic partially reflective surface. Then, by using the proposed wideband circuit model, we predict the gain and 3dB gain bandwidth of the antenna, assumed as infinitely large in the transverse domain (for the modeling purposes). Finally we compared the circuit model results to the full-wave ones for a FPC antenna of finite extent. © 2009 IEEE.

In this paper, a design of Fabry-Pérot Cavity antenna at millimiter-waves frequencies is investigated. Four Fabry-Pérot cavity antennas, covered by different Frequency Selective Surfaces, are discussed which are fabricated on a Quartz disk to guarantee mechanical stability and also for ease of fabrication, probing and measurement. A planar feed, a slot dipole fed by a coplanar waveguide, is also designed to excite the cavities. Prototypes have been designed and fabricated at central frequencies in frequency range of 42 to 46 GHz with various gains; however the same design can be adopted at higher frequencies. Full-wave simulations, done by Ansys HFSS, are verified with measurement results. © 2011 IEEE.

A simple solution for a 63 GHz planar single-feed Fabry-Pérot cavity (FPC) antenna covered by a thick metallic frequency selective surface (FFS) is proposed. The antenna is fed through a planar feed consisting of a coplanar-waveguide-fed slot on the ground plane of the cavity. The FSS is made of periodic circular slots in a thick Brass plate. Moreover, the sides of the metallic FSS are terminated with vertical metallic walls leading to a self-supported low-profile FPC filled with air. Good agreement is observed between measured and simulated results. © 2013 IEEE.

In this work we compare the performance of metamaterials based on layers of planar pair conductors with various shapes: dogbone with rectangular and triangular lattice, square loop and gangbuster. We first show the characteristics of transmission, reflection and absorption, and then we compare the absorption coefficient for the four considered structures. We inspect the dependence of the absorption coefficient on unit cell metal density in the case of triangular lattice dogbone pair and gangbuster pair. Last, we analyze the behavior of artificial magnetic conductors made by a single periodic layer of planar conductors above a grounded substrate. © 2011 IEEE.

We proposed a personalized intervention that integrates computerized working memory (WM) training with real-time functional neuromonitoring and neurofeedback (NFB) to enhance frontoparietal activity and improve cognitive and clinical outcomes in children with attention-deficit/hyperactivity disorder (ADHD). The study involved 77 children with ADHD aged 7-11 years, who were assigned to either 12 sessions of NFB or treatment-as-usual (i.e., received standard clinical care) groups. Real-time neuromonitoring with functional near-infrared spectroscopy (fNIRS) and fMRI measured frontoparietal activity during n-back task at baseline and post-intervention. Thirty-six participants (21 NFB, 15 treatment-as-usual) completed the study. Significant improvements in NFB group were observed in frontoparietal brain activity and WM performance (primary outcomes). NFB group also showed improvements in Behavior Rating Inventory of Executive Function (BRIEF-2) WM t-scores and Conners 3 ADHD index scores (secondary outcomes) compared to treatment-as-usual group. These findings suggest that neuromonitoring-guided NFB effectively enhances cognitive and clinical outcomes in children with ADHD by targeting brain mechanisms underlying WM deficits.