Comparative analysis of Noise Radar (NR) and Quantum Radar (QR) concepts are presented in the paper. Recently proposed methods for generation of quantum correlated signals directly in microwave frequency range give more chances for design of QR for long-range applications. In many applications, the range resolution capability is of a great importance. Novel concept of Stepped-Frequency Quantum Radar (SF-QR) for design of QR with range resolution capability is suggested. FPGA based digital generation of entangled signals is discussed as well.
Comparative analysis of Noise Radar (NR) and Quantum Radar (QR) concepts are presented in the paper. Recently proposed methods for generation of quantum correlated signals directly in microwave frequency range give more chances for design of QR for long-range applications. In many applications, the range resolution capability is of a great importance. Novel concept of Stepped-Frequency Quantum Radar (SF-QR) for design of QR with range resolution capability is suggested. FPGA based digital generation of entangled signals is discussed as well.
Recently proposed methods for generation of entangled (quantum correlated) signals directly in microwave frequency range give more chances for design of QR for long-range applications. In such applications, the range resolution capability is of a great importance. Using analogy of signal generation and processing in Noise Radar and Quantum Radar we describe a novel concept for Stepped-Frequency QR (SF-QR) design which enables preserving quantum properties of probing signals and provide range resolution capability in SF-QR.
Preliminary results of the comparative analysis of quantum radar (QR) based upon quantum entanglement phenomenon and noise radar (NR) based upon classical coherence and correlation processing of random signals are presented in this article. Common and distinguishing features of NR and QR are briefly discussed. A novel concept of a stepped-frequency quantum radar (SF-QR) for design of QR with range resolution capability is suggested. Field programmable gate array based digital generation of entangled signals is proposed as well.
Preliminary results of the comparative analysis of Quantum Radar (QR) based upon quantum entanglement phenomenon and Noise Radar (NR) based upon classical coherence notion and correlation processing of random signals are presented in the paper. It has been shown that the basic idea of entangled multi-photon QR for simultaneous implementing of high penetrating ability of the entangled photons and high spatial resolution performance does not work because of decay of entangled state of the transmitted photons when they hits a wall, for example. QR operation abilities may be described in terms of classical physics. In addition, the multi-photon QR has been modeled by means of classically phase locked multi-frequency signals (regular and chaotic). Results of computer simulation of basic properties for such radar are presented.
This work, written for engineers or managers with no special knowledge of quantum mechanics, nor deep experience in radar, aims to help the scientific, industrial, and governmental community to better understand the basic limitations of proposed microwave quantum radar (QR) technologies and systems. Detection and ranging capabilities for QR are critically discussed and a comparison with its closest classical radar (CR), i.e., the noise radar (NR), is presented. In particular, it is investigated whether a future fielded and operating QR system might really outperform an “equivalent” classical radar, or not. The main result of this work, coherently with the recent literature, is that the maximum range of a QR for typical aircraft targets is intrinsically limited to less than one km, and in most cases to some tens of meters. Detailed computations show that the detection performance of all the proposed QR types are orders of magnitude below the ones of any much simpler and cheaper equivalent “classical” radar set, in particular of the noise radar type. These limitations do not apply to very-short-range microwave applications, such as microwave tomography and radar monitoring of heart and breathing activity of people (where other figures, such as cost, size, weight, and power, shall be taken into account). Moreover, quantum sensing at much higher frequencies (optical and beyond) is not considered here.
This article presents a comprehensive analysis of two classes of quantum radars, including quantum direct-detection and quantum-entangled noise radars. In the first case, inspired by the well-established concept of single-photon LiDARs, we investigated the performance of single-photon radars, in which state-of-the-art single microwave-photon detectors are employed to enhance the detection sensitivity and enable the detection of weaker signals. We derived analytical expressions for the maximum detection range of both classes of quantum radars in terms of the Lambert W function, by considering all relevant system, target, and environmental parameters. Our formulation facilitates direct comparison of noise radars with direct-detection radars and suggests that a quantum-entangled noise radar can be regarded as an enhanced direct-detection radar with an effective threshold signal-to-noise ratio. Furthermore, we applied this framework to classical-correlated noise radars and defined the parameter range enhancement factor (REF) to quantify the superiority of quantum-entangled noise radars over their classical counterparts. Moreover, we introduced a rule-of-thumb for approximating the REF. We also examined the influence of limitations imposed by various microwave detection technologies. Our analysis shows that the conventional antennas limit the potential benefits of quantum-entangled noise radar systems. We also demonstrated that the optimal detection method for these radars is a microwave detector based on a quantum transducer combined with a single optical-photon detector. We showed that, with the current technology, implementing a quantum-entangled noise radar with the maximum detection range on the order of few kilometers is possible. Finally, we explored the potential applications of quantum-entangled noise radars.
Both Noise Radar (NR) and Quantum Radar (QR), with alleged common features, aim to use the randomness of the transmitted signal to enhance radar covertness and to reduce mutual interference. While NR has been prototypically developed and successfully tested in many environments by different organizations, research and development investments on QR did not bring to practically operating prototypes. Starting from the well-known fact that radar detection depends on the energy transmitted on the target, the detailed evaluations in this work show that the detection performance of all the QR types proposed in the literature are well below the ones of a much simpler and cheaper equivalent “classical” radar set, for example of the NR type. Moreover, the absence of a “Quantum radar cross section” different from the well-known radar cross section is explained. From these facts it results that, in spite of alleged advantages in some literature, Quantum Radar proposals cannot lead to useful results, including, of course, the detection of stealth targets.