| 摘要 |
A true time delay beamformer for RF/microwave phased array antenna systems using multiple laser sources, optical modulators to convert the electrical signal to a modulated optical signal, standard optical fiber for creating time delays, dispersive optical fiber for creating delays, optical splitting and/or switching section, photodetectors to convert the modulated optical signal to an electrical signal, and a signal combining section. The true time delay beamformer has the capability to create multiple simultaneous RF/microwave antenna beams. One (more lasers) is used to source one (or more) wavelengths of light to the optical modulator. The signal from one (or more) antenna elements drive the optical modulator. The light from the optical modulator passes through the standard optical fibers and/or the dispersive optical fibers to create time delay variation for one optical modulator relative to another allowing for the formation of RF/microwave beams. Fixed location RF/microwave beams can be generated by a static network of standard and/or dispersive optical delay fibers. Steering of the location of the RF/microwave beams can be accomplished by an optical switching mechanism which could be based on MEMs and/or wavelength routing based switching. Finally, all the signals for a RF/microwave beam are summed to form a single output. The summing can occur either optically before the photodetectors and/or electrically after the photodetectors.
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