Nederlandse Organisatie Voor Toegepast-natuurwetenschappelijk Onderzoek Tno

Agence Spatiale Europeenne

European Space Agency

Marco Sabbadini

Andrea Neto

Giampiero Gerini

Stefano Maci

Lucio Gerardo Scolamiero

Gabriele Minatti

Paolo Patrizio De Vita

Simona Bruni

A method for designing a surface pattern for an impedance surface which results in a position-dependent target impedance of said impedance surface, and the impedance surface having the position-dependent target impedance radiates a desired first-type electromagnetic field radiation in reaction to being irradiated by a second-type electromagnetic field radiation. The method includes obtaining a first modal representation on the basis of the first-type electromagnetic field radiation in terms of a set of base modes that are chosen in accordance with a model function of the position-dependent target impedance, and obtaining a second modal representation on the basis of the second-type electromagnetic field radiation and the model function in terms of the set of base modes. The method further includes obtaining a first position-dependent quantity indicative of the position-dependent target impedance on the basis of the first modal representation and the second modal representation by determining values for a plurality of parameters of the model function for maximizing an overlap between the first modal representation and the second modal representation, and obtaining, as the surface pattern, a second position-dependent quantity indicative of geometric characteristics of the impedance surface on the basis of the first position-dependent quantity and a relationship between geometric characteristics of the impedance surface and corresponding impedance values.

Method for designing a modulated metasurface antenna structure

A reconfigurable reflector for electromagnetic waves, comprising: a rigid support element () having a front surface (); an elastically deformable reflective membrane () lying over the front surface of said rigid support element; and a plurality of linear actuators () for deforming said reflective membrane by operating on predetermined points thereof; wherein said linear actuators are embedded within said rigid support element, and have shafts () protruding by the front surface thereof for operating on predetermined points of said elastically deformable reflective membrane. Preferably, the rigid support element comprises a reflector dish having a sandwich structure having a honeycomb core () made of CFRP or aluminum, in which the linear actuators are embedded by conventional potting techniques. Antenna system comprising such a reconfigurable reflector, possibly operating as a subreflector (SR), and spacecraft telecommunication.

Reconfigurable reflector for electromagnetic waves

An antenna comprises a conically shaped body of dielectric material. Cross-sections of the body have truncated elliptical shape, wherein each shape is truncated substantially through a first focus of the elliptical shape along a truncation line that extends substantially perpendicularly to a main axis of the elliptical shape. The second focus of the elliptical shape lies within the body. An elongated wave carrying structure such as a slot in a conductive ground plane extends substantially along a focal line through the first focus of the elliptical shapes in successive cross-sections. This structure supports transmission and/or reception over a wide range of frequencies. In an embodiment a multi-frequency feed structure is integrated in the ground plane of the antenna.

Broadband leaky wave antenna

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Leiden, Netherlands

Marco Sabbadini