An antenna architecture comprises a hybrid beamformer comprising on the one hand, Ny stacked quasi-optical beamformers, each quasi-optical beamformer comprising a parallel-plate waveguide furnished with a linear radiating aperture and integrating a lens and internal horns furnished with beam access ports, each quasi-optical beamformer forming beams in two, transmission and reception, frequency bands, in a first direction in space, and on the other hand, at least one electronic beamformer comprising a combining device linked to Nx phase and amplitude control chains, 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.