Ricerc@Sapienza

Compact high-gain wideband antenna systems for through-the-wall imaging and wireless communications, featuring 160% fractional bandwidth, are presented. Each radiating system, consisting of two orthogonal Vivaldi antennas forming a cross-shaped configuration so to excite linear (horizontal/vertical) and circular polarization (CP), is equipped with a top-mount spherical-axicon dielectric lens. The optimized shaping of the lens and of the outer edge Vivaldi arms allow achieving gain levels exceeding 15dBi with good front-to-back-ratio.

Polarimetric diversity has been recently shown to significantly improve the target detection performance in passive radar systems, if properly exploited to mitigate the competing interference. An adaptive processing scheme is presented in this work, leveraging the information conveyed using multi-polarized receiving antennas and modeling the disturbance as a multichannel autoregressive process.

Suitable methods to jointly exploit the diversity of information conveyed by different polarimetric channels in Passive Coherent Location (PCL) systems are a topic of current research. Possible signal processing strategies were devised for FM radio based PCL with the purpose of enhancing the target detection capability and their benefits were largely demonstrated. This paper presents the results from a preliminary investigation carried out considering a multi-channel PCL system exploiting DVB-T signals.