Abstract: A positioning system for radio frequency devices includes a two-way radio antenna, for vehicles, having a transmitting and a receiving element. Reference antennas have retro-directive arrays which can shape the signal beams in elevation; polarize transmission and reception signals according to a circular or a linear polarization, the polarized transmission retro-directively reflecting signals having the same polarization as the incident ones in the case of circular polarization, or retro-directively reflecting signals having orthogonal polarization in the case of linear polarization. An encoder is included for transmitting an identification code of the reference antenna. A controller processes the spatial and temporal data resulting from communication through the radio waves transmitted and received by the vehicle antennas and reflected by the reference antennas. The controller calculates the distance of the vehicle from the reference antennas that have reflected the signal transmitted by the antennas.

Abstract: A positioning system for radio frequency devices includes a two-way radio antenna, for vehicles, having a transmitting and a receiving element. Reference antennas have retro-directive arrays which can shape the signal beams in elevation; polarize transmission and reception signals according to a circular or a linear polarization, the polarized transmission retro-directively reflecting signals having the same polarization as the incident ones in the case of circular polarisation, or retro-directively reflecting signals having orthogonal polarisation in the case of linear polarisation. An encoder is included for transmitting an identification code of the reference antenna. A controller processes the spatial and temporal data resulting from communication through the radio waves transmitted and received by the vehicle antennas and reflected by the reference antennas. The controller calculates the distance of the vehicle from the reference antennas that have reflected the signal transmitted by the antennas.

Abstract: The present invention relates to a flat scanning antenna (1) comprising: a radiant unit (2; 2a), having a flat shape and comprising in its turn one or more radiant waveguides (7) arranged side by side as array, said radiant waveguides (7) being in their turn divided in one or more modules (9), on each of them there is one or more slots (6) arranged on the same plane to receive or transmit radio-frequency signals; and at least one beam forming network (8), connected to said radiant unit (2; 2a), to feed said modules (9) of said radiant waveguides (7) with proper phases, in order to realize the scanning of a radiant beam in elevation with respect said radiant unit (2; 2a).