Active antenna architecture with reconfigurable hybrid beamforming

1. An active antenna architecture with reconfigurable beamforming, comprising a hybrid beamformer comprising:

Ny stacked planar quasi-optical beamformers, where Ny is an integer number greater than one, each quasi-optical beamformer comprising a parallel-plate waveguide having two ends respectively furnished with a linear radiating aperture and with My beam access ports, a lens integrated into the parallel-plate waveguide, internal horns distributed periodically side by side along a focal axis of the lens, the beam access ports being respectively associated with the internal horns, each quasi-optical beamformer forming beams in two separate frequency bands, respectively for transmission and for reception, in a first direction in space parallel to the plane of the parallel-plate waveguides, and

at least one planar electronic beamformer comprising Ny phase and amplitude control chains and a combining device comprising Ny inputs respectively linked to the Ny phase and amplitude control chains and at least one beam output, each phase and amplitude control chain being connected to a respective beam access port of each quasi-optical beamformer, the electronic beamformer forming beams in a second direction in space, orthogonal to the first direction.

2. The antenna architecture according to claim 1 , further comprising switches for selecting, in each quasi-optical beamformer, a port from among all the available beam access ports, each switch comprising an input connected to a phase and amplitude control chain of the electronic beamformer and several outputs respectively connected to several respective beam access ports of the corresponding quasi-optical beamformer.

3. The antenna architecture according to claim 2 , wherein the beam access ports consist of a first row of transmission ports disposed side by side along the focal axis of the lens and of a second row of reception ports disposed side by side along the focal axis of the lens, the first and the second rows being stacked one above the other, the transmission ports and the reception ports having different sizes, each transmission port, respectively reception port, being furnished with a respective filter centred on the transmission, respectively reception, frequency band.

4. The antenna architecture according to claim 2 , wherein the linear radiating apertures of the various quasi-optical beamformers are linked as an array to a single partially reflecting radome, common to all the quasi-optical beamformers, the radome comprising a first partially reflecting surface dimensioned for the reception frequency sub-band and a second partially reflecting surface dimensioned for the transmission frequency sub-band, the first and second partially reflecting surfaces being respectively disposed at the output of the linear radiating apertures, at a distance corresponding to a respective central wavelength of the two transmission and reception frequency sub-bands.

5. The antenna architecture according to claim 3 , wherein the hybrid beamformer comprises a quasi-optical beamformer common to transmission Tx and to reception Rx, two distinct specific electronic beamformers, respectively dedicated to transmission and to reception, and switches comprising various positions respectively able to select a beam access port from among several, each switch selectively linking, according to its position, a phase and amplitude control chain of the electronic beamformer dedicated to transmission, respectively to reception, to one of the transmission ports, respectively reception ports, of each quasi-optical beamformer.

6. The antenna architecture according to claim 4 , wherein the hybrid beamformer comprises a quasi-optical beamformer common to transmission Tx and to reception Rx, two distinct specific electronic beamformers, respectively dedicated to transmission and to reception, and switches comprising various positions respectively able to select a beam access port from among several, each switch selectively linking, according to its position, a phase and amplitude control chain of the electronic beamformer dedicated to transmission, respectively to reception, to one of the transmission ports, respectively reception ports, of each quasi-optical beamformer.

7. The antenna architecture according to claim 5 , wherein the beam access ports, selected by the switches in all the stacked quasi-optical beamformers and linked to one and the same electronic beamformer, have an identical direction of orientation and cover an identical geographical sector.

8. The antenna architecture according to claim 5 , wherein a first part of the beam access ports selected by the switches in the stacked quasi-optical beamformers covers a first geographical sector and a second part of the beam access ports selected by the switches in the stacked quasi-optical beamformers covers a second geographical sector adjacent to the first geographical sector.

9. The antenna architecture according to claim 1 , wherein the combining device consists of a combiner/divider comprising Nx inputs respectively linked to the Nx phase and amplitude control chains and a beam output.

10. The antenna architecture according to claim 1 , wherein the combining device comprises a branch-off to split each phase and amplitude control chain into several different pathways, each pathway comprising a dedicated phase-shifter.

11. The antenna architecture according to claim 1 , wherein the combining device consists of a quasi-optical beamformer based on PCB technology comprising Nx inputs respectively linked to the Nx phase and amplitude control chains and several beam outputs.