Le Norme di CEM per la Suscettività prevedono valutazioni di tipo qualitativo. A fronte della opportunità di strumenti obiettivi risultano in letteratura lavori [1]-[2] che sperimentano l'uso del Test del Rapporto di Massima Verosomiglianza (GLRT) [3], esemplificandolo per disturbi condotti nei quali è misurabile un segnale periodico [4]; il risultato obiettivo è il superamento da parte della funzione T (obiettivo del test) della soglia fissata dalla percentuale ammissibile di giudizi erroneamente negativi, denominata Probabilità di falso Allarme. Questo lavoro indaga sulla applicabilità del GLRT a disturbi radiati con segnale monitorabile non periodico bensì continuo. Si considera un rilevatore di %ale di O2 irradiato nella banda 80-130 MHz con livelli di campo E pari a 5-10-15 V/m; il segnale misurabile è la intensità di corrente DC controllata dal sensore. I risultati delle misure, con PFA=0.05, indicano che la funzione T supera la soglia, in accordo a effettivi malfunzionamenti.

Per le applicazioni previste dalla Norma IEEE 802.15.3c sono auspicabili antenne ricoprenti l’intera banda 57-66 GHz. Il presente lavoro indaga sull’impiego di schiere di antenne stampate su dielettrici a singolo strato e a basso costo. Le fasi progettuali nella realizzazione di tale antenna sono: 1°individuazioni di singoli patch con larghezza di banda maggiore di 10 GHz; 2°) configurazione di schiere per ottenere i diagrammi di radiazione richiesti; 3°) configurazione delle reti di alimentazione e adattamento. Recentemente è apparso in letteratura un lavoro [4] nel quale la piena copertura in banda dei quattro canali prevosti dalla Norma citata, è realizzata da una schiera stampata alimentata da rete di linee co-planari, mentre per schiere stampate con linee a microstriscia , la copertura in banda si limita a due canali [5]. In questo lavoro si tenta l’estensione della copertura, con VSWR<2, all’intera banda tramite idonea progettazione della rete di alimentazione e adattamento.

Recently composite right/left-handed (CRLH) leakywave antennas (LWAs) have been shown as one of the applications of the CRLH transmission line (TL) metamaterials thanks to their advantages of fabrication simplicity and frequency/electrically scanning capability without any complex feeding network. Neverthless the fixed geometrical size of a unit cell of the CRLH-TL Leaky-wave antennas, prevents the possibility to improve the antenna bandwidth "tapering" the geometrical size of unit cell. This paper presents a realization of composite right/left handed transmission lines LWA using different size of unit cell to design a single antenna. This structure exploits the advantages of a classic CRLH leaky-wave antennas, while increases the bandwidth. The performance of this tapered composite right/left-handed line were demonstrated by both simulated and measured results, and they show good agreement.

This paper presents a transmission line model used to design an inverted F antenna (IFA) at the frequency of 2.45 GHz. This model provides a quickly design of a printed F antenna antenna that can be easily integrated into handheld devices or printed on PCMCIA cards for WLAN communications in the ISM band. A simple iterative method which consider inductive or capacitive loadings was adopted to design the antenna in conjunction with a 3D EM simulators obtained a good solutions to design IFA. A prototype of proposed planar inverted F antenna (PIFA) has been manufactured on a FR4 substrate with a bandwidth of 230 MHz in order to demonstrate the reliability of the model validated by the good agreements with the experimental and simulated measurements.

This paper introduces a new design to made RFID tags on metamaterial substrate. The metamaterial substrate has a potential to reduce the circuit size of the antenna as well as maintain the performance of the tag made on classical substrate. The behavior of the metamaterial substrate proposed was analysed in terms of S-parameters by commercial simulator to verify its negative permittivity. The simulation result of RFID antenna on metamaterial substrate shown an improvement of the performance compared to the conventional design of the tag antenna, paving the way to the future implementation of these tags. I

A study is presented of wireless on-body communication links, with the body in motion. This paper compares simulations and measurements of the path gain (PG) on moving male and female bodies. Simulations using avatars derived from an animation software have been performed at 2.45 GHz. Male and female avatars walking and a male rising from a chair have been simulated and the results are compared with measurements carried out in an anechoic chamber. The results show that good agreement between simulation and measurement of slow fading features can be achieved for a reasonable computational effort.

In this paper, an antenna array is designed in order to transform the thermal energy, provided by the Sun and re-emitted from the Earth, in electricity. The proposed antenna array is constituted by four square spirals of gold printed on a low cost dielectric substrate. A microstrip line, embedded into the substrate, is used to feed the array and to collect the thermal radiation. The dispersive behavior of gold at infrared frequencies has been taken into account through the LorentzeDrude model. Simulations have been conducted in order to investigate the behavior of the antenna array illuminated by a circularly polarized plane wave with an amplitude chosen according to the StefaneBoltzmann radiation law. An output current of about 3.8 mA has been simulated at 28.3 THz, i.e. at the frequency of the Earth emitted radiation. Moreover, these infrared antennas could be coupled with other components to obtain direct rectification of infrared radiation. As a consequence, these structures further optimized could be a promising alternative to the conventional photovoltaic solar cells.

An annular slot antenna suitable for pattern diversity in wideband applications is presented. Pattern diversity is obtained by feeding the antenna simultaneously with two microstrip lines printed on the back of the substrate, which generate orthogonal radiation patterns. Two shorts placed at 45 degrees between the microstrip lines and in the opposite direction ensure an isolation above 15 dB according to measurements. The antenna operates in the range of frequencies from 3 GHz to 12 GHz (1:4 bandwidth) and covers many different standards (Wireless-LAN, HIPERLAN2, WIMAX, UWB). Simulations and measurements for return loss, isolation and radiation patterns are presented. Furthermore, measurements have been carried out in a real multipath environment in order to evaluate pattern diversity performance. Results of measurements of the correlation coefficient and diversity gain over the entire operating bandwidth show that the antenna is suitable for antenna diversity systems.

It is well known that the hyperthermia (HT) treatment method in cancer therapy makes use of the controlled electromagnetic heating in the patient’s body. With regard to the deep body hyperthermia therapy, we have reviewed in this paper the most recent technology and technique of electromagnetic deep heating (Sigma-Eye applicator) based on annular phased arrays (APA) antennas. In order to improve the performance of the Sigma-Eye applicator, a new profile of the antenna was designed using a substrate material with high permittivity. The good results of the simulations compared with the classical Sigma-Eye applicator in terms of SAR deposition and focus capability lead us to further improvements of both the heat generation devices and the treatment planning methods.

Four different high power ytterbium doped fiber lasers are designed and compared via a home-made computer code. Their effective mode areas and beam qualities are numerically evaluated. A novel aperiodic fiber microstructure, very promising in order to construct high power and single mode lasers, has been identified.

In the fields of electromagnetic interference and electromagnetic compatibility, it is important to measure the strength of the electric field originating from electric devices. Knowledge of the antenna factor of a receiving antenna is necessary. In this paper, we discuss the antenna impedance method as a new calibration method measuring the free-space antenna factor. The experimental measurements are compared with both the standard field method and the data provided by the manufacturer of biconical, log-periodic and horn antennas. A good agreement with the technical regulation ANSI C63.5.