Integrated microphotonic broadband smart antenna beamformer

A novel architecture for a microphotonic beamformer that generates variable RF true-time delays to steer broadband nulls for smart antennas, is presented. The beamformer employs a Vertical Cavity Surface Emitting Laser (VCSEL) array, photoreceiver array, and micro-optics integrated on an optical substrate through which many delayed versions of the RF are generated, amplified and combined to synthesise broadband spatial nulls that can adoptively be steered. Results show that a 6-element MicroPhotonic broadband smart antenna beamformer operating in the 5-GHz band can generate 5 deep nulls with less than 2 dB degradation in main beam gain, and less than 1.5 beam squint over 1 GHz bandwidth, and for less than 2.5% of maximum delay time fluctuations, null depths of more than 40 dB can be obtained.