Patent ID: 7042397
Filing Date: 2006-05-09
Classification: H01Q

Abstract:
1. A phase-shifting cell of a reconfigurable reflectarray for an antenna operating in the microwave range, said reflectarray comprising: a plurality of identical elementary phase-shifting cells, each of said cells having two plane parallel faces separated by a thickness representing about one quarter of the wavelength of the operating frequency; said first face having a star-configured array including an even number of electrically conducting strands that are all identical and placed uniformly around a central disk, which is also conducting; it being possible for each strand to be electrically connected to the central disk via a switching device dependent on a control voltage; each pair of diametrically opposed strands thus constituting, when the two switching devices connecting them to the central disk are activated, a resonant dipole in the range of operating frequencies of the antenna, the second face including a ground plane, said cell each switching device including a micro-electromechanical system comprising a flexible membrane supported by at least two pillars that are placed between said membrane and the first face of the cell, said membrane thus being placed above the end of each strand facing the central disk and that peripheral part of said disk which is placed facing this end, said membrane, when the control voltage is applied, being deformed by the resulting electrostatic force sufficiently to ensure electrical connection between the end of the strand and the corresponding peripheral part of the central disk, said switching device being of the capacitor type and the electrical connection corresponds to a large increase in its capacitance.