2022, Articolo in rivista, ENG
Maksutoglu, Maksut; Ghirri, Alberto; Yorulmaz, S. Cigdem; Yildiz, Fikret; Affronte, Marco; Rameev, Bulat
Studies on spin waves (magnons) formed by collective electron spin excitations in magnetic materials have recently gained importance due to their great potential for magnonics and hybrid quantum systems. In this study, the magnetostatic spin-wave modes excited as a result of the coupling between the 2D microwave resonator and the YIG sphere have been investigated computationally. The simulations have been performed using commercial finite element method software (CST Studio Suite). The 2D microwave resonator is realized on the ground plane of the broadband microstrip structure by using a low-loss printed circuit board. The calculations reveal the Q factor to be about 300 by optimizing the resonance frequency to 7 GHz. The most interesting result of simulations is the observation that the magneto-static spin-wave modes of the YIG sphere may be excited depending on the geometry of the hybrid structure. A strong interaction between the YIG and the microwave resonator observed in the dispersion curves of these modes reveals the realization of the strong coupling regime, which is a prerequisite of their use in quantum hybrid devices.
2021, Contributo in atti di convegno, ENG
Vincenza Portosi, Antonella M. Loconsole, Marcello Valori, Valeria Marrocco, Francesco Bonelli, Giuseppe Pascazio, Vito Lampignano, Antonella Fasano, Roberto Lorusso, Francesco Prudenzano
In this paper, the design and optimization of a low-cost needle microwave applicator for cancer therapy is illustrated. An adequately sized coaxial antenna inserted into a thin hypodermic needle, is optimized in the Industrial, Scientific and Medical frequency band (ISM) at f = 2.45 GHz. An extensive feasibility investigation is performed in order to obtain an efficient, mini-invasive and low-cost microwave medical device. Several technical solutions are explored and the optimization of a number of needle microwave applicators is performed. The performance of the applicators is evaluated in terms of antenna impedance matching, specific absorption rate (SAR), temperature distribution, and ablation zone sizes. After a comparison, a 14 gauge (14G) and a 16 gauge (16G) prototypes are fabricated and characterized.
2013, Articolo in rivista, ENG
Amendola, Giandomenico; Angiulli, Giovanni; Arnieri, Emilio; Boccia, Luigi; De Carlo, Domenico
In recent years, Artificial Neural networks (ANNs) have been intensively employed to build smart model of microwave devices. In this paper a characterization of lossy SIW resonators by means of Multilayer Perceptron Neural Networks (MLPNNs) on Graphics Processing Unit (GPU), is presented. Once properly selected and trained, a MLPNN can evaluate the lossy SIW resonator's resonant frequency fr and the pertaining quality factor Q at a shorter time than the full-wave rigorous model. In this way, fast parametric models of SIW structures to employ for the design and optimization of microwave devices, exploiting the computational power of GPUs, can be obtained.
2013, Articolo in rivista, ENG
Macelloni, G.a and Brogioni, M.a and Pettinato, S.a and Zasso, R.b and Crepaz, A.b and Zaccaria, J.c and Padovan, B.c d and Drinkwater, M.e
In recent years, there has been growing interest on the part of the remote sensing community in using the Antarctic area for calibrating and validating data of low-frequency satellite-borne microwave radiometers. In particular, the East Antarctic Plateau appears to be suited for this purpose. The reasons for this interest are the size, structure, spatial homogeneity, and thermal stability of this area. This is particularly interesting for low-frequency microwave radiometers since, due to the low extinction of dry snow, the upper ice-sheet layer is almost transparent and the brightness temperature variability is therefore extremely small. In the context of calibration and validation activities of the European Space Agency's Soil Moisture and Ocean Salinity (SMOS) satellite, an experiment called DOMEX-2, which included radiometric L-band measurements, was carried out at the Italian-French base of Concordia located at Dome C in the East Antarctic Plateau from December 2008 to December 2010. Ground measurements (i.e., snow temperature at different depths, snow structure, meteorological data, etc.) were also collected during the experiment. This paper presents information on the experimental campaign, the characteristics of the radiometric measurements, and the main results. A comparison with SMOS data is also presented.
2008, Articolo in rivista, ENG
Angiulli, G.; Arnieri, E.; De Carlo, D.; Amendola, G.
In recent years Artificial Neural Networks have been adopted as an alternative modelling approach for the design of microwave circuits. In this work a characterization of circular resonators realized in substrate integrated waveguide (SIW) technology by means of Artificial Neural Networks is presented. SIW resonators are analyzed considering the scattering of the ensemble of metallic vias pieced in a parallel plate waveguide. Resonances are efficiently located looking at an estimate of the smallest singular value. Results carried out for circular resonators demonstrate the effectiveness of the method. ©2008 IEEE.
2006, Articolo in rivista, ENG
Marcelli R, Nikitov SA, Filimonov YA, Gahshnikov AA, Kozhevnikov AV, Dudko GM
Magnetostatic surface wave (MSSW) bright solitons in a ferrite-dielectric-metal (FDM) structure have been studied experimentally and numerically in the framework of the nonlinear. Schrodinger equation. Attention was focused on the influence of the parametric instability on the soliton formation and propagation. We also discussed the contribution of the nonsolitary (dispersive wave) part of the MSSW pulse on the soliton propagation, to show that their mutual interference leads to the leveling off or to the appearance of some peaks in the MSSW pulse output versus the input amplitude. We have also shown that for MSSW pulses with rectangular shape, the linear pulse compression caused by an induced phase modulation of the input pulse must be taken into account. Experiments were performed on FDM microstrip structures loaded by a 14-mu m-thick yttrium iron garnet film, separated from the ground metal by an air gap with thickness h(1) approximate to 100 mu m or h(2) approximate to 200 mu m. It was found experimentally for MSSW with wavelength lambda approximate to h. that the modulation instability leads to soliton formation for rectangular input pulses with duration T less than the characteristic transient time t* needed for the onset of the parametric instability, while pulses with T >= t* are mainly subjected to parametric instability. The measured threshold amplitudes for parametric and modulation instabilities are in agreement with the theoretical predictions. An influence of additional pumping in the form of both continuous-wave and pulsed signals on the soliton formation was studied. It was shown that an additional pumping signal with duration tau >= t*, and amplitude above the threshold of the parametric instability, suppressed the MSSW soliton. Numerical modeling of the pulsewidth dependence on the microwave power during the propagation in the FDM structure yields results that are in agreement with the experimental observations. Moreover, pulse narrowing due to the induced phase modulation of the input pulse was numerically predicted. All of these effects are in agreement with the experimental findings.
2005, Brevetto di invenzione industriale, ENG
R. Tascone, M. Baralis, G. Virone, O. A. Peverini, A. Olivieri
A waveguide correlation unit and a method for manufacturing the same are disclosed. The waveguide correlation unit comprises stacked first and second waveguide plates having an identical configuration, wherein a central coupling plate is disposed therebetween. Due to the identical configuration of the first and second waveguide plates, mechanical uncertainties may significantly be reduced, since both plates may be formed in a common process without the repositioning activities during the manufacturing process.
2002, Articolo in rivista, ENG
Filimonov, Y.A. , Marcelli, R. , Nikitov, S.A.
The influence of the modulation and parametric four-magnon instabilities on the propagation of magnetostatic surface wave (MSSW) pulses in a delay line configuration has been experimentally studied in a ferrite-dielectric-metal structure. It was possible to distinguish the influence of both instabilities by changing the dispersion properties of the exploited device. The contribution of additional MSSW continuous wave and pulsed signals on the propagation of MSSW pulses has been also considered.
1996, Articolo in rivista, ENG
Marcelli, R. , Rossi, M., De Gasperis, P.
In this work the microwave response of an integrated structure composed of coupled magnetostatic wave (MSW) straight edge resonators (SER) based on an epitaxial yttrium iron garnet film and measured by means of a ferromagnetic resonance (FMR) experiment has been studied. By using the FMR spectra, a simulation of microwave filters based on integrated SERs has been performed, demonstrating great potential in the realization of planar MSW tunable devices.