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This paper report on the development and field trial of a dual-band and dual-use system based on a single photonics-based transceiver and a single radiating element, able to simultaneously carry out radar and communication functionalities. The coexistence of the two operations does not introduce any penalty on the system performance. The innovative sharing of both transceiver and antenna element allows for a reduction in terms of cost and Size Weight and Power consumption. The dual-use radar-communication system has been demonstrated in a outdoor field trial combining a radar experiment in S-band and C-band OFDM (Orthogonal Frequency Division Multiplexing) communication

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In this paper, a dual-band photonics-based radar system used for precise displacement measures in a multitarget scenario is described. The radar was designed for monitoring applications to prevent both structural failures of buildings and landslides. The radar system exploits the technique of stepped frequency continuous wave signal modulation and the displacement of the targets is evaluated through differential phase measurements. In this work, encouraged by the results already achieved in the single-target scenario, we present an investigation extended to the case of multiple targets. We aim to evaluate the accuracy of the displacement estimation both from a simulated and experimental point of view, and to understand how multiple targets impact on the final estimate of displacements. Simulation results demonstrate that it is possible to achieve a typical accuracy of less than 0.2 mm for distances up to 400 m. These results are confirmed by preliminary experimental outcomes, which take into account different operative conditions with multiple targets. Finally, concluding remarks and perspectives draw the agenda for our future investigations.

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This work reports a dual-band radar system composed of aphotonics-based transceiver and a unique dual-band antenna. The proposed antenna consists of an integration of conventional focal-point and Cassegrain parabolic antennas in the same structure, ensured by using a subreflector based on a frequency selective surface. Numerical and experimental results in terms of the antenna reflection coefficient, radiation pattern and gain are reported with excellent agreement over both frequency ranges. The innovative dual-band photonics-based radar transceiver operates simultaneously in the Sand X-bands. The radar system has been properlyvalidated by multiple detections of helicopters and airplanes in real conditions.

Photonics-based multiband radars have been demonstrated where photonics is exploited for multiple RF signal generation and detection by means of a single optical local oscillator that replaces the conventional cascades of electrical local oscillators. The ultra-wide band and high stability of photonics and the use of a single local oscillator assure very low system phase noise and phase coherence among the RF signals. This phase coherence among multi-band signals is exploited to perform differential phase estimation in enhanced sub-millimeter displacement measures. The system employs stepped frequency continuous waves simultaneously in the Sand X-band, measuring the differential phase over a frequency span up to 7.4GHz. The high coherence among the two frequency bands, provided by the photonic architecture, enables very precise displacements measures, allowing to obtain sub-millimeter precision without using correction algorithms. The presented experimental results demonstrate a precision < 200m in a range up to 3km. Moreover, the sharing of the same hardware to handle a multi-band operation allows a great reduction of size, weight, power and footprint of the overall system.