Ricerc@Sapienza

Use of non-ionizing radiation (NIR) for diagnostic purposes allows non-invasive assessment of the structure and function of the human body and is widely employed in medical care. ICNIRP has published previous statements about the protection of patients during medical magnetic resonance imaging (MRI), but diagnostic methods using other forms of NIR have not been considered.

Microwave thermal ablation (MTA) procedures are based on the absorption of an electromagnetic field irradiated by a minimally invasive antenna. Several studies have been conducted in the past considering different aspects of the technique. However, some points still need to be investigated, as pointed out in the present contribution.

The dispersive features of a 2-D planar leaky-wave antenna constituted by an annular slot grating on a dual-layer grounded dielectric slab are presented in this contribution. A well-established in-house method-of-moments dispersion code has been suitably generalized to account for a multi-layer substrate and to assist in the characterization of the corresponding linearized structure.

Fabry-Perot cavity antennas with polarization-reconfigurable omnidirectional conical beams are presented. The partially reflecting screen covering the antenna cavity is constituted by omnidirectional homogenized metasurfaces exhibiting rotationally invariant electromagnetic features, and specifically metal patterned screens are considered. The antenna operates on the first higher-order TMi and TEi leaky modes, whose phase and attenuation constants are properly equalized.

In this paper, a new model of the frequency dependence of the double-barrier THz rectifier is presented. The new structure is of interest because it can be realized by CMOS image sensor technology. Its application in a complex field such as that of THz receivers requires the availability of an analytical model, which is reliable and able to highlight the dependence on the parameters of the physical structure. The model is based on the hydrodynamic semiconductor equations, solved in the small signal approximation.