Patent ID: 6191748
Filing Date: 2001-02-20
Classification: H01Q

Abstract:
An active microwave reflector, capable of receiving an electromagnetic wave linearly polarized in a first given direction, the reflector comprising a set of elementary cells positioned beside one another on a surface,each cell comprising a phase-shifter microwave circuit and a conductive plane positioned substantially parallel to the microwave circuit, at a predefined distance from this circuit, this distance being smaller than half of the smallest wavelength of the operating band of the reflector,the phase-shifter circuit comprising a dielectric support, at least one electrically conductive wire substantially parallel to the given direction, positioned on the support and bearing at least two two-state semiconductor elements, the wire being connected to control conductors for the semiconductor elements that are substantially normal to the wires, the control conductors being at least three in number to control the state of the semiconductor elements independently of one another, and second conductive zones positioned towards the periphery of the cell substantially in parallel to the control conductors,the geometrical and electrical characteristics of the cell being such that, to each of the states of the semiconductor elements, there corresponds a given value of phase-shift (d.phi..sub.1, d.phi..sub.2, d.phi..sub.3, d.phi..sub.4) of the electromagnetic wave that is reflected by the cell,the reflector furthermore comprising an electronic circuit to control the state of the semiconductor elements, connected to the control conductors and means of microwave decoupling between the cells, these means comprising a second conductive zone positioned between each cell, parallel to the given direction, this second conductive zone forming, with the conductive plane, a guided space where the wave cannot get propagated.