Gianfranco Ruggerini - Academia.edu (original) (raw)

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Papers by Gianfranco Ruggerini

Electronic Systems for Remote Sensing and Ranging, 1980

Military Microwaves '86, 1986

A corporate feed developed in suspended substrate stripline for the pyramidal-horn linear array o... more A corporate feed developed in suspended substrate stripline for the pyramidal-horn linear array of an X-band radar antenna is described. The suspended substrate has been analyzed and synthesized using a specially developed computer program. The power unbalance of power dividers has been minimized (maximum value, 4.09 dB) in order to improve the bandwidth and phase insertion. All the components show

2017 11th European Conference on Antennas and Propagation (EUCAP), 2017

The paper deals with the extensive use of optimization techniques at Space Engineering during the... more The paper deals with the extensive use of optimization techniques at Space Engineering during the several phases of development of antenna sub-systems for satellite applications.

A simple numerical representation for arrays of different-sized rectangular waveguide apertures h... more A simple numerical representation for arrays of different-sized rectangular waveguide apertures has been described. The analytical expression of mutual admittance given by T.S. Bird (see IEEE Trans. Antennas Propag., vol.38, no.2, 166-72 1990) is evaluated by means of a direct integration method where the highly oscillatory integrand is locally approximated by a linear form and solved in closed form to evaluate the contribution of a single incremental area. Expressions of all applicable symmetry and reciprocity conditions have been derived. The need for using a large number of modes has also been observed. The effectiveness of the theory in predicting the performance of rectangular waveguide arrays, with closely packed elements, has been analyzed comparing measured and computed data of two different arrays. Though the numerical results denote a substantial improvement of the array modelling, the need of more accurate coupling formulas, together with the study of the scattering matri...

17th European Microwave Conference, 1987, 1987

This paper presents the main results of a feasibility study aimed at defining the antenna subsyst... more This paper presents the main results of a feasibility study aimed at defining the antenna subsystem of a European DBS satellite. The antennas of the satellite radiate a large number of channels over seven multinational, partially overlapping, coverages. The mass and volume optimization requires the minimization of the number of antennas and therefore each antenna of the subsystem must produce more than one coverage. A solution based on multiple contoured beam configurations is presented. Coverage overlapping is obtained by horn sharing whilst beam isolation is provided through frequency diversity and/or polarization discrimination.

Ninth International Conference on Antennas and Propagation (ICAP), 1995

Current and proposed satellite communications systems demand dual-linearly polarised transmit-rec... more Current and proposed satellite communications systems demand dual-linearly polarised transmit-receive antennas for contoured and/or multiple beam coverages. The proven means of satisfying these requirements is by the use of dual-gridded parabolic reflectors with two separated feed arrays radiating opposite linear polarizations. The two parabolic dishes are gridded in perpendicular directions and placed in front of one another with independent focal points to maintain separated the relevant feed arrays and beamforming networks. This paper describes the results of an activity performed on the design of large and highly-shaped dual-gridded reflector antennas. The critical aspects in developing a reflector shaping technique based on an optimization algorithm are discussed. The advantage in compensating for the effects of reflector thermal distortions during the electrical antenna design are also demonstrated. This novel technique allows a less critical thermal control of the reflector assembly, with a consequent reduction of the development time, hardware mass, and ohmic losses.

Proceedings of the 5th European Conference on Antennas and Propagation (EUCAP), 2011

Some advances on the design, manufacturing and testing of an aperiodic bootlace active lens gener... more Some advances on the design, manufacturing and testing of an aperiodic bootlace active lens generating a multiple spot contiguous beams coverage are presented in the paper. The antenna represents an interesting architecture based on a single aperture able to replace conventional antennas based on multi reflector dishes onboard geo or non-geo stationary satellites. The antenna has been optimized in terms of number of radiators, dimensions, weight, and power amplifiers efficiency. The first experimental results on a passive antenna system have demonstrated interesting features. The implementation of a real active solution is now on going.

Proceedings of the Fourth European Conference on Antennas and Propagation, 2010

This paper describes a novel very compact circular horn with high aperture efficiency. The horn p... more This paper describes a novel very compact circular horn with high aperture efficiency. The horn presents a profile very waving to achieve the optimum waveguide mode conversion yielding an extremely reduced horn depth (about 1.2 time the aperture diameter) and an aperture efficiency greater than 90% over a 10% bandwidth for aperture dimensions up to 6λ.

Electronics

This paper presents the design, manufacturing, and testing of a Ku-band magnified active Tx/Rx mu... more This paper presents the design, manufacturing, and testing of a Ku-band magnified active Tx/Rx multibeam antenna based on a discrete constrained lens. Multibeam antennas based on constrained lenses generate a significant number of beams on a large operative frequency bandwidth. The main novelty and challenge in this development are associated with the combined transmitting and receiving functionality of this active array. An innovative RF building blockchain working in dual-polarization and covering both the transmitting and receiving bandwidth is successfully implemented. In order to improve the accommodation constraints and the thermal control, the active lens is magnified by two confocal paraboloidal reflectors. To validate the design procedure, experimental results are compared with numerical ones.

IEEE Antennas and Propagation Magazine

Proceedings of the 5th European Conference on Antennas and Propagation, Apr 11, 2011

Some advances on the design, manufacturing and testing of an aperiodic bootlace active lens gener... more Some advances on the design, manufacturing and testing of an aperiodic bootlace active lens generating a multiple spot contiguous beams coverage are presented in the paper. The antenna represents an interesting architecture based on a single aperture able to replace conventional antennas based on multi reflector dishes onboard geo or non-geo stationary satellites. The antenna has been optimized in terms of number of radiators, dimensions, weight, and power amplifiers efficiency. The first experimental results on a passive antenna system have demonstrated interesting features. The implementation of a real active solution is now on going.

In the paper one aperiodic constrained active lens generating a multiple spot contiguous beams co... more In the paper one aperiodic constrained active lens generating a multiple spot contiguous beams coverage is proposed. The antenna is optimized in terms of number of radiators, dimensions, weight, and power amplifiers efficiency. The antenna represents an interesting architecture based on a single aperture able to replace conventional antennas based on multi reflector dishes onboard geo or non-geo stationary satellites. Experimental results recently achieved are presented.

Electronic Systems for Remote Sensing and Ranging, 1980

Military Microwaves '86, 1986

A corporate feed developed in suspended substrate stripline for the pyramidal-horn linear array o... more A corporate feed developed in suspended substrate stripline for the pyramidal-horn linear array of an X-band radar antenna is described. The suspended substrate has been analyzed and synthesized using a specially developed computer program. The power unbalance of power dividers has been minimized (maximum value, 4.09 dB) in order to improve the bandwidth and phase insertion. All the components show

2017 11th European Conference on Antennas and Propagation (EUCAP), 2017

The paper deals with the extensive use of optimization techniques at Space Engineering during the... more The paper deals with the extensive use of optimization techniques at Space Engineering during the several phases of development of antenna sub-systems for satellite applications.

A simple numerical representation for arrays of different-sized rectangular waveguide apertures h... more A simple numerical representation for arrays of different-sized rectangular waveguide apertures has been described. The analytical expression of mutual admittance given by T.S. Bird (see IEEE Trans. Antennas Propag., vol.38, no.2, 166-72 1990) is evaluated by means of a direct integration method where the highly oscillatory integrand is locally approximated by a linear form and solved in closed form to evaluate the contribution of a single incremental area. Expressions of all applicable symmetry and reciprocity conditions have been derived. The need for using a large number of modes has also been observed. The effectiveness of the theory in predicting the performance of rectangular waveguide arrays, with closely packed elements, has been analyzed comparing measured and computed data of two different arrays. Though the numerical results denote a substantial improvement of the array modelling, the need of more accurate coupling formulas, together with the study of the scattering matri...

17th European Microwave Conference, 1987, 1987

This paper presents the main results of a feasibility study aimed at defining the antenna subsyst... more This paper presents the main results of a feasibility study aimed at defining the antenna subsystem of a European DBS satellite. The antennas of the satellite radiate a large number of channels over seven multinational, partially overlapping, coverages. The mass and volume optimization requires the minimization of the number of antennas and therefore each antenna of the subsystem must produce more than one coverage. A solution based on multiple contoured beam configurations is presented. Coverage overlapping is obtained by horn sharing whilst beam isolation is provided through frequency diversity and/or polarization discrimination.

Ninth International Conference on Antennas and Propagation (ICAP), 1995

Current and proposed satellite communications systems demand dual-linearly polarised transmit-rec... more Current and proposed satellite communications systems demand dual-linearly polarised transmit-receive antennas for contoured and/or multiple beam coverages. The proven means of satisfying these requirements is by the use of dual-gridded parabolic reflectors with two separated feed arrays radiating opposite linear polarizations. The two parabolic dishes are gridded in perpendicular directions and placed in front of one another with independent focal points to maintain separated the relevant feed arrays and beamforming networks. This paper describes the results of an activity performed on the design of large and highly-shaped dual-gridded reflector antennas. The critical aspects in developing a reflector shaping technique based on an optimization algorithm are discussed. The advantage in compensating for the effects of reflector thermal distortions during the electrical antenna design are also demonstrated. This novel technique allows a less critical thermal control of the reflector assembly, with a consequent reduction of the development time, hardware mass, and ohmic losses.

Proceedings of the 5th European Conference on Antennas and Propagation (EUCAP), 2011

Some advances on the design, manufacturing and testing of an aperiodic bootlace active lens gener... more Some advances on the design, manufacturing and testing of an aperiodic bootlace active lens generating a multiple spot contiguous beams coverage are presented in the paper. The antenna represents an interesting architecture based on a single aperture able to replace conventional antennas based on multi reflector dishes onboard geo or non-geo stationary satellites. The antenna has been optimized in terms of number of radiators, dimensions, weight, and power amplifiers efficiency. The first experimental results on a passive antenna system have demonstrated interesting features. The implementation of a real active solution is now on going.

Proceedings of the Fourth European Conference on Antennas and Propagation, 2010

This paper describes a novel very compact circular horn with high aperture efficiency. The horn p... more This paper describes a novel very compact circular horn with high aperture efficiency. The horn presents a profile very waving to achieve the optimum waveguide mode conversion yielding an extremely reduced horn depth (about 1.2 time the aperture diameter) and an aperture efficiency greater than 90% over a 10% bandwidth for aperture dimensions up to 6λ.

Electronics

This paper presents the design, manufacturing, and testing of a Ku-band magnified active Tx/Rx mu... more This paper presents the design, manufacturing, and testing of a Ku-band magnified active Tx/Rx multibeam antenna based on a discrete constrained lens. Multibeam antennas based on constrained lenses generate a significant number of beams on a large operative frequency bandwidth. The main novelty and challenge in this development are associated with the combined transmitting and receiving functionality of this active array. An innovative RF building blockchain working in dual-polarization and covering both the transmitting and receiving bandwidth is successfully implemented. In order to improve the accommodation constraints and the thermal control, the active lens is magnified by two confocal paraboloidal reflectors. To validate the design procedure, experimental results are compared with numerical ones.

IEEE Antennas and Propagation Magazine

Proceedings of the 5th European Conference on Antennas and Propagation, Apr 11, 2011

Some advances on the design, manufacturing and testing of an aperiodic bootlace active lens gener... more Some advances on the design, manufacturing and testing of an aperiodic bootlace active lens generating a multiple spot contiguous beams coverage are presented in the paper. The antenna represents an interesting architecture based on a single aperture able to replace conventional antennas based on multi reflector dishes onboard geo or non-geo stationary satellites. The antenna has been optimized in terms of number of radiators, dimensions, weight, and power amplifiers efficiency. The first experimental results on a passive antenna system have demonstrated interesting features. The implementation of a real active solution is now on going.

In the paper one aperiodic constrained active lens generating a multiple spot contiguous beams co... more In the paper one aperiodic constrained active lens generating a multiple spot contiguous beams coverage is proposed. The antenna is optimized in terms of number of radiators, dimensions, weight, and power amplifiers efficiency. The antenna represents an interesting architecture based on a single aperture able to replace conventional antennas based on multi reflector dishes onboard geo or non-geo stationary satellites. Experimental results recently achieved are presented.