Optically Beamformed Wideband Array Performance

Optical beamforming networks (OBFNs) are an interesting alternative for the design of wideband antenna arrays, mainly due to their low losses and weight, their high parallel processing capabilities and their electromagnetic immunity. Nevertheless, for a practical implementation, different technological and architectural tradeoffs need to be assessed. In this paper, the performance of an OBFN system is analytically studied and experimentally demonstrated. The study forms part of the optical beamforming network project, a multigroup research project supported by the European Space Agency (ESA). Differently from bulky free-space geometries, the architecture is based on fiber-optic delay lines for the time delays generation and on a spatial light modulator for the phase shifts generation. Experimental results for an X-band prototype are provided, showing beam steering accuracy, multibeam capability, amplitude distribution weighting and wideband operation.