Communications: radio wave antennas – Antennas – With spaced or external radio wave refractor
Reexamination Certificate
2000-03-22
2001-02-20
Le, Hoanganh (Department: 2821)
Communications: radio wave antennas
Antennas
With spaced or external radio wave refractor
C343S755000, C343S909000
Reexamination Certificate
active
06191748
ABSTRACT:
BACKGROUND OF THE INVENTION
An object of the invention is an microwave reflector with electronically steered scanning that can be illuminated by a microwave source to form an antenna.
Electronically steered scanning antennas are usually formed by a set of radiating elements emitting a microwave whose phase can be electronically controlled, independently for each element or group of elements. An antenna whose beam is capable of scanning space in two orthogonal directions (2D) requires a large number of radiating elements. Their cost, namely the cost of the phase-shifters and of the associated electronic circuitry, generally makes this type of antenna very costly.
The aim of the invention is to enable the making of a 2D electronically steered scanning antenna for a cost that is substantially smaller, for comparable performance characteristics, than that of known antennas.
SUMMARY OF THE INVENTION
To this end, the antenna according to the invention consists of a linearly polarized microwave source illuminating an active microwave reflector. The active reflector according to the invention comprises a set of elementary cells, each comprising a phase-shifter microwave circuit placed before a conductive plane. This phase-shifter comprises conductive wires or tracks positioned on a support, the wires or tracks each comprising at least two two-state semiconductor elements, for example diodes, and being connected to conductors by which the states of the diodes can be controlled independently of each other, it being possible for each of the diodes to be on or off. Thus, four possible states are obtained and the geometrical and electrical characteristics of the cell are such that a given phase-shift value corresponds to each of these states. Finally, microwave decoupling means are provided between the cells. These means consist, in particular, of waveguides formed between two neighboring cells. The walls of these waveguides are parallel to the polarization of the waves and the spacing between these waveguides is such that it prohibits the propagation of the wave.
REFERENCES:
patent: 4017865 (1977-04-01), Woodward
patent: 4212014 (1980-07-01), Chekroun
patent: 4320404 (1982-03-01), Chekroun
patent: 4344077 (1982-08-01), Chekroun et al.
patent: 4447815 (1984-05-01), Chekroun et al.
patent: 5001495 (1991-03-01), Chekroun
patent: 5144327 (1992-09-01), Chekroun et al.
patent: 5237328 (1993-08-01), Dorey et al.
patent: 5373302 (1994-12-01), Wu
patent: 5548289 (1996-08-01), Chekroun et al.
patent: 5598172 (1997-01-01), Chekroun
patent: 5635939 (1997-06-01), Chekroun
patent: 5680136 (1997-10-01), Chekroun
Chekroun Claude
Dubois Michel
Guillaumot Georges
"Thomson-CSF"
Le Hoang-anh
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
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