Quantum Radar: State of the Art and Potential of a Newly-Born Remote Sensing Technology

Quantum technology has already been introduced in many fields, like information processing and communications, and it can potentially change our approach to remote sensing in the microwave and millimeter-wave domain, leading to systems known as Quantum Radars. This new generation of systems does not leverage directly on quantum entanglement, since the latter is too “fragile” to preserve in a noisy and lossy environment,as a radar scenario,but rather on thehigh level of coherence derived from quantum entanglement. Quantum Illuminationisaprocess that exploitsquantum coherence of non-classical states of lightfor remote sensing. It allows for the generation and reception of highly correlatedsignals in the form of optical ormicrowave photons. By correlating the received signal photons with photons entangled with the transmitted ones,it is possible toclearly distinguish, among all the received photons, the echoes from background noise and interferences, boosting to an unprecedented level the sensitivity of remote sensing. Therefore, in principle,it is possible to detect very lowcross-radar section objets, such as stealth targets. Nowadays, very few experiments on Quantum Radar transceivers have been reported. This work aims at summarizing the state of the art of Quantum Radar, introducing its basic working principles, though raising the possible issues of such a technology; secondly, it will point out the possibilitiesof photonics-assisted Quantum Radars, proposing photonics as the ideal field where quantum science and remote sensing can meet for an effective cross-fertilizatio

Via-Less Microstrip to Rectangular Waveguide Transition on InP

Indium-Phosphide (InP) is one of the most common materials used for realizing active devices working in the millimeter frequency range. The isotropic etching profile of InP substrates limits the realization of passive devices, thus requiring an expensive and lossy hybrid platform. This paper presents a via-less, cost-effective and efficient solution for InP substrate. By using the proposed planar solution, it is demonstrated that rectangular waveguides can be realized on InP by fabricating a bed of nails structure which acts as a reflecting boundary for an impinging millimeter wave. As a proof of concept, a transition from microstrip to rectangular waveguide structure is realized within H-band (220-320 GHz) with a return loss of -18dB over a bandwidth of 30 GHz

Assessment of COVID-19 pandemic impact on guaranteeing food security in local school catering

Background. The Italian National Institute of Statistics (ISTAT) highlights that in 2020 10% of the Italian population could not afford an adequate meal every 2 days. Families with several children were more affected, for these children school meals represented the only access to a healthy diet. The European Commission Farm to Fork Strategy, concerning the COVID-19 pandemic (CP), underlines the need to act to ensure access to a sufficient supply of affordable food for all. In the Province of Trieste (PT) over 90% of pupils eat in school canteens (12,000 meals per day). The aims of the project were to verify the impact of CP on the food security of public school canteens (PSC) and determine any Nutritional Critical Points (NCPs) - Corrective Actions (CAs) to guarantee healthy equity meals for all pupils. Methods. The content of Public food procurement and service polices for a healthy diet (PFP) published by the WHO and the Nutrient Analysis Critical Control Points (NACCP) process as indicated by the Ministry of Health were applied. In the first quarter of 2021, all food procurement contracts (n = 6) and all of the school kitchens (n = 45) of PT PSC were verified, the University of Trieste analysed the composition of fresh desserts administered in 7 consecutive weeks. Results. The NACCP process showed NCPs on the low quality of afternoon snacks and on the quantitative/qualitative fat profile of fresh desserts, with a content of 69 to 72% of saturated fat, of 5 to 7% of trans fat and of 8 to 12% oxidized fat as a “dual quality” food. CAs were activated to support all PT PSC in reformulating fresh desserts, as well as in aiding the assessment of the food procurement landscape, activating regular monitoring of compliance and designing procurements adherent to PFP. Conclusions. Project outcomes highlight the importance of taking action to continuously support PSC in order to ensure healthy and equitable food environments for all and to contribute to building a resilient food system. Key messages. Guarantee healthy equity school meals for all pupils by developing on going processes to address the pandemic challenge. Ensure technical assistance to school catering to overcome the impact of COVID–19

Flexible multi-band OFDM receiver based on optical down-conversion for millimeter waveband wireless base stations

A novel and flexible photonics-based down-conversion scheme is proposed for wireless receivers in base stations. It allows simultaneous detection of multiple signals at carriers up to tens of GHz, enabling communications at millimeter waves. Experiments demonstrate the effective down-conversion of Wi-Fi signals at 2.4 and 39.8GHz with EVM<;-43dB

Distributed coherent radars enabled by fiber networks

In the last few years, we have been proposing the use of photonics to bring new functionalities in radar systems, exploiting its precision and tunability to give radars improved performance and reconfigurability. This paper will present the most recent evolution of the original idea of photonics-based radars, which considers the exploitation of the increasingly available fiber connections to implement a network of widely distributed radars. The centralized photonic approach allows driving several separated radars simultaneously, enabling the novel class of distributed coherent radar systems. Through the implementation of specific multi-input multi-output (MIMO) processing, the photonics-enabled radar network is capable to push the radar detection resolution far beyond the limits usually set by the signal bandwidth alone

Widely distributed photonics-based dual-band MIMO radar for harbour surveillance

A new architecture for a widely distributed dual-band coherent multiple-input multiple-output (MIMO) radar system is illustrated, and its implementation and testing are reported. The system consists in a central unit where radar signals are coherently generated and detected, which serves multiple remote sensors connected over transparent WDM optical network. Every remote node operates coherently both in the S- and X-band, and is displaced over distances of several kilometers, allowing to monitor a scene under different angles of view. All the remote sensors share the same oscillator and digital signal processing unit, both located in the central office, allowing to perform centralized raw data fusion on the acquired signals. By virtue of the system coherence, the system takes advantage of the coherent MIMO processing strategy to offer a superior spatial resolution, which is even magnified by the dual-band approach

Photonics enabling coherent MIMO radar networks

The potential of coherent MIMO radar networks enabled by photonics is introduced. The first coherent dual-band 2 × 4 MIMO radar experiment is presented. Range/cross-range maps demonstrate the higher cross-range resolution due to the coherence and the enhanced performance introduced by dual-band operation

The Orbital Angular Momentum of Light for Ultra-High Capacity Data Centers

The potential of orbital angular momentum (OAM) of light in data center scenarios is presented. OAMs can be exploited for short reach ultra-high bit rate fiber links and as additional multiplexing domain in transparent ultra-high capacity optical switches. Recent advances on OAM integrated photonic technology are also reported. Finally demonstration of OAM-based fiber links (aggregate throughput 17.9 Tb/s) and two layers OAM-WDM-based optical switches are presented exploiting OAM integrated components and demonstrating the achievable benefits in terms of size, weight and power consumption (SWaP) compared to different technologies

In-Field Demonstration of a Photonic Coherent MIMO Distributed Radar Network

This paper reports an in-field experiment of a photonics-based coherent MIMO radar network. The use of photonics guarantees the coherence of the transmitted and received RF signals, and allows remoting the antennas exploiting deployed optical fibers, thus a MIMO approach can be applied on a network of widely distributed coherent radars. In the in-field experiment, a photonics-based radar core connects two transmitters and two receivers, with 100-MHz bandwidth signals in X-band, observing a collaborative target. The results demonstrate an improvement in radar precision, and envisage real applications wherever fiber is available for deploying the radar network