Papers by Stefano Selleri
Chain-mail armor was a type of body protection that dates back to the fourth century BC. It was u... more Chain-mail armor was a type of body protection that dates back to the fourth century BC. It was used extensively in times of war up to the advent of fi rearms. It had a limited use later on, but was still reported as being worn up to the 20th century. The modern uses of chain mail are mostly civilian, such as protection for butchers, shark protection for divers, and, notably, for historical reenactment and live-action role-playing games. In these latter cases, there is no need that the chain mail really be weapon proof, and it is usually made of aluminum to reduce weight. It is legitimate to ask ourselves if chain mail could be used as a wearable shield against electromagnetic radiation.
IEEE Antennas and Propagation Society International Symposium. Digest. Held in conjunction with: USNC/CNC/URSI North American Radio Sci. Meeting (Cat. No.03CH37450)
An heuristic model for the passive intermodulation analysis has been recently derived in a time d... more An heuristic model for the passive intermodulation analysis has been recently derived in a time domain physical optics framework. The heuristic approach proposed requires the determination of few coefficients which has been pursued, previously, by a trial-and-error procedure. Here a genetic algorithm is introduced for the automatic evaluation of the optimum values for these coefficients.
IEEE Antennas and Propagation Society International Symposium. 2001 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.01CH37229)
A history of radio communications is sketched, up to the description of the first land and sea mi... more A history of radio communications is sketched, up to the description of the first land and sea microwave links realized by Guglielmo Marconi in 1932. Some consideration on early microwave applications and on the first use of the word "microwave" is also presented
URSI Radio Science Bulletin, 2017
IEEE Antennas and Propagation Society International Symposium. Transmitting Waves of Progress to the Next Millennium. 2000 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.00CH37118)
Full wave analysis of cylindrical posts in rectangular waveguide for antenna networks is in this ... more Full wave analysis of cylindrical posts in rectangular waveguide for antenna networks is in this paper replaced with a properly trained artificial neural network. The network is able to give an accurate description of the post behaviour at a given frequency in real time, whereas the full wave simulator would take several minutes. This will be of great importance in synthesis problem.
IEEE Antennas and Propagation Society International Symposium. Transmitting Waves of Progress to the Next Millennium. 2000 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.00CH37118)
A new corrective term to complete the array factor for dielectric resonator antennas array is pro... more A new corrective term to complete the array factor for dielectric resonator antennas array is proposed. The term is derived on considerations based on the coupling of neighbouring elements and takes into account the true electric distance between the phase centres of the antennas. Results are compared with conventional array theory, previous work dealing with corrective terms and measures
IEEE Antennas and Propagation Society International Symposium. Transmitting Waves of Progress to the Next Millennium. 2000 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.00CH37118)
The parabolic equation is applied to the problem of the scattering from a diaphanous wedge, that ... more The parabolic equation is applied to the problem of the scattering from a diaphanous wedge, that is a wedge made of a material which is isorefractive with respect to the surrounding medium, illuminated by a plane wave. The proposed numerical approach is able to handle any wedge aperture angle and incidence angle. Cases with an arbitrary number of internal reflections
IEEE Antennas and Propagation Society International Symposium. 1999 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.99CH37010), 1999
Passive intermodulation (PIM) is a phenomenon which often arises at junctions between different m... more Passive intermodulation (PIM) is a phenomenon which often arises at junctions between different materials. This may be a major issue in tightly packed antenna farms as those typically present on communication satellites. Here an heuristic non-linear extension to the time domain physical optics is proposed, to take into account electromagnetic scattering at intermodulated frequencies when such a junction is illuminated by two impinging electromagnetic fields at different frequencies.
IEEE Antennas and Propagation Society International Symposium. Digest. Held in conjunction with: USNC/CNC/URSI North American Radio Sci. Meeting (Cat. No.03CH37450)
An application programmer interface (API) is devised to allow for an easy creation of virtual ele... more An application programmer interface (API) is devised to allow for an easy creation of virtual electromagnetic laboratories. The API provides the programmer with a fully automatic graphical user interface, freeing him from the daunting task of programming it directly through Matlab objects.
2006 International Waveform Diversity & Design Conference, 2006
Here some variations of the basic Particle Swarm algorithm (a relatively novel approach for globa... more Here some variations of the basic Particle Swarm algorithm (a relatively novel approach for global stochastic optimisation) are proposed in order to increase the efficiency of the search over the solution space with a negligible overhead in the algorithm complexity and speed. The resulting algorithms have been first compared in terms of capability and speed of convergence by their application to a test function, then the resulting best technique has been used for the design of a microwave filter.
2010 IEEE International Conference on Wireless Information Technology and Systems, 2010
The problem of antenna shape synthesis has received a growing interest during the last years. Dif... more The problem of antenna shape synthesis has received a growing interest during the last years. Different general Global optimization algorithms such as Genetic Algorithms, Particle Swarm Optimization have been developed as well as deterministic algorithms. An initial effort is described to develop an antenna synthesis procedure for planar configurations from a Hybrid Conjugate Gradient Method. Typical results obtained are presented
IEEE Antennas and Propagation Society International Symposium. 1999 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.99CH37010)
An artificial neural network (ANN) analysis of profiled corrugated circular horns is proposed. Th... more An artificial neural network (ANN) analysis of profiled corrugated circular horns is proposed. This technique allows, on the basis of a reduced number of full-wave analysis, for the supervised learning of an ANN able to interpolate accurate results for a large class of horns. The performances in computing time of the ANN are far better than those of the full-wave
2005 IEEE Antennas and Propagation Society International Symposium
ABSTRACT An integrated workspace for a Matlab-based suite of codes aimed at an educational use of... more ABSTRACT An integrated workspace for a Matlab-based suite of codes aimed at an educational use of finite elements is presented. The codes present several classical FEM applications, ranging from guiding structure characterization, to microwave devices and radiation problems and fully exploit Matlab's graphical capabilities to enhance the ease of use and optimize the learning curve.
Waveguide transitions are frequently used in telecommunications hardware to interconnect rectangu... more Waveguide transitions are frequently used in telecommunications hardware to interconnect rectangular or circular waveguides feeding the reflector antennas with internal active circuits, often realized in MMIC technology with microstrip, coplanar wave guide and other guiding structures. In this contribution, the effects of manufacturing tolerances on this kind of transitions are analyzed both in qualitative terms and in quantitative ones using a Monte Carlo method applied to FEM electromagnetic simulations. Measures on a W-Band prototype are used to validate the approach.
IEEE Antennas and Propagation Society International Symposium (IEEE Cat. No.02CH37313)
ABSTRACT Compact horns with highly stable phase centre reduce efficiency dropping for defocusing ... more ABSTRACT Compact horns with highly stable phase centre reduce efficiency dropping for defocusing at the frequency band extremes. In this contribution an automatic design procedure for such horns, based on a parallel genetic algorithm, is described. The algorithm operates on many horn profile parameters, including corrugations, and is based on an accurate full-wave mode matching/combined field integral equation analysis code.
International Journal of RF and Microwave Computer-Aided Engineering, 2020
This article applies a new method to analyze modes in empty waveguides having perfectly conductin... more This article applies a new method to analyze modes in empty waveguides having perfectly conducting walls and a rather generic cross-section. The method is based on a coordinate transformation that maps the generic profile of the waveguide cross-section to a circular waveguide (CW) filled with an anisotropic material. Modes in this latter waveguide can be represented as a series over the corresponding free-space CW modes. This representation is particularly useful if used as a modal expansion over the port of a 2.5D or 3D device treated with a transformation optics approach. The method is particularly efficient when the waveguide is "similar" to a CW. Applications are shown to the analysis of some waveguides of arbitrary cross-section with a view on practical applications.
International Journal of RF and Microwave Computer-Aided Engineering, 2020
This paper presents a novel approach to the localization of moving targets in a complex environme... more This paper presents a novel approach to the localization of moving targets in a complex environment based on the measurement of the perturbations induced by the target presence on an independently-generated time-varying electromagnetic field. Field perturbations are measured via a set of sensors deployed over the domain of interest and used to detect and track a possible target by resorting to a particle Bernoulli filter (PBF). To comply with real-time operation, the PBF works along with an artificial neural network (ANN) model of the environment trained offline via finite elements (FEs). The performance of the proposed algorithm is assessed via simulation experiments.
IEEE Antennas and Propagation Society International Symposium, Jun 20, 2004
In this paper, some considerations on a recently developed heuristic model for taking into accoun... more In this paper, some considerations on a recently developed heuristic model for taking into account passive intermodulation (PIM) in electromagnetic scattering are carried out to get a better insight on the model itself. The time domain physical optics method is used in the PIM heuristic model. Considerations are focused on the PIM level as a function of the incident power so as to verify that results are compatible with independent measures.
2008 IEEE Antennas and Propagation Society International Symposium, 2008
ABSTRACT We have presented a combined DD-MOR method, which extends existing approaches by incorpo... more ABSTRACT We have presented a combined DD-MOR method, which extends existing approaches by incorporating the DD in the generation process of the ROM. The DD method allows the efficient use of a multipoint MOR procedure, since only the subdomain containing parameter-dependent features has to be solved at the ROM interpolation points. In future work, we will extend our approach to frequency and geometry parameters, and demonstrate its efficiency in optimization scenarios.
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Papers by Stefano Selleri