Rodolfo Ravanelli

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A high-gain mushroom-shaped dielectric resonator (DR) antenna for wideband wireless applications, featuring 65% fractional bandwidth, is proposed. The antenna consists of a low-permittivity hollow cylindrical DR provided with a top-mount spherical cap lens and a metal reflector, excited by means of coaxial probes. Suitable shaping of lens and reflector(More)
A multi-objective optimization approach has been applied to the synthesis problem of the geometrical structure of antenna with complex set of requirement specification. This methodology is a promising tool for new development and application for several kind of microwave structure.
Three different RF chain architectures operating in the FSS (Fixed Satellite Services) + BSS (Broadcast Satellite) spectrum are presented and discussed. The RF chains are based on a common wideband corrugated feed horn, but differ on the approach used for bands and polarizations separation. A breadboard of a novel self-diplexed configuration has been(More)
In the typical Earth facing panel several high performance antennas are allocated in very close condition, so that it is necessary to use advanced electromagnetic models to calculate the impact of the complex mechanical supporting structure on the radiated fields. This work has been addressed to evaluate the undesired effects caused by the supporting struts(More)
A novel triple-band, self-diplexing feed system operating in K/Ka/EHF bands is presented. The feed system is particularly suitable in space telecom reflector antennas for dual-use applications. Two different RF chain architectures have been traded-off, designed and optimized through full wave modelling, in order to support the optimal choice solution. An(More)
This paper presents the research activity carried out jointly by the IEIIT -CNR and Thales Alenia Space Italy aimed at the development of multi-band systems. The paper focuses on a synthesis technique that is applied to the design of single- and multi-band feed horns.
The problem of non-linear electromagnetic scattering from complex structures is here addressed. Non-linear scattering is critical in satellite environment, where many powerful transmitters are closely packed with many high sensitivity receivers since the passive intermodulation components due to the transmitters can interfere with the receivers. In this(More)
Satellite antenna require very tight performance in terms of edge of coverage (EOC) gain, crosspolarisation discrimination (XPD), absolute level of cross polarisation and side lobe mask over the global coverage. A dual "ridded reflector (DGR) antenna is the best compromise between electrical performance and mechanical envelope. It consist of two single(More)
Two different methodologies based on resonator techniques are presented. The first has been realized for wide band reflectivity characterization at high temperature while the second has been developed to verify surface resistivity including roughness, surface contamination and other undesired effect. Both methods have been developed for characterization(More)