Telecommunications > Communications > Applied electromagnetics

Macchiarella Giuseppe

http://risorse.dei.polimi.it/emclab/

Focus

Innovative techniques for microwave circuits design
The aim of this research area is to develop innovative and effective solutions for designing passive and active microwave circuits typically employed in telecommunications equipments (mobile communications, point-to-point and point-to-multipoint radio links). A significant part of the work is developed in the area of microwave filters synthesis, where novel techniques have been developed for inline topologies with arbitrary transmission zeros; innovative methods have been also developed for duplexers and multiplexers and multiband filters for base stations of mobile communications. Other research activities concern the automatic tuning of microwave filters (employing a suitable implementation of the Cauchy method) and the physical dimensioning of filters by means of the spacemapping approach. Researches in the field of microwave active circuits have concerned the design of new architecture for linearization of microwave power amplifiers.

Numerical methods for electromagnetics
Focus is on the development of new and efficient full-wave techniques for accurate analysis and design of microwave. We are working on two main topics: the first one concerns suitable extensions of Finite Integrate Technique (FIT) for allowing the extraction of equivalent circuits suitable for the filter design. The second topic is the development of an efficient formulation for the Method of Moments interfaced to the Mode-matching method, in order to analyze circular corrugated horns both standalone and in a cluster configuration.

Antennas
Research topics in this area concern modelling and design of adaptive arrays for broadcast and telecommunication based on multibeam antennas with Butler-matrix based distribution network; modelling of the overall system and of power distribution to the output feeds; planar arrays for mobile communication systems; design of a low-cost two-dimensional array for cellular base stations.

Most relevant research achievements


Microwave filters synthesis
A new technique for the synthesis of microwave filters/duplexers/ multiplexers with inline topology and arbitrarily displaced transmission zeros. The algorithm allows the association of the imposed transmission zeros to specific topological blocks.

Dualband filters synthesis
A novel procedure for the synthesis of filters with two passbands. The procedure is based on a suitable frequency transformation which, starting from an inline prototype with asymmetric frequency response in an intermediate frequency domain, allows the analytical evaluation of the coupling matrix of the dualband filter.

Active predistorter for MMIC power amplifier
This achievement concerns a novel kind of linearizer architecture specifically developed for power amplifiers implemented as monolithic integrated circuits.

Automated tuning of microwave filters
A method for the computer-aided alignment of microwave filters has been developed. The novel technique (applicable to both filters and duplexers) is based on the Cauchy method for extracting a polynomial model from the measurements of the device to be tuned.

Numerical Methods for Electromagnetics and Antenna design
Implementation of efficient numerical tools for the analysis of single and coupled circular corrugated horns. Extension of Finite Integrate Technique (FIT) to include boundary quantities. Efficient analysis of cylindrical insets in rectangular waveguide by a Generalized Admittance Matrix approach.