The quantum computing began with the concern of Richard Feynman to simulate the non-classical physical theories, Shor's algorithm showed the power of the quantum mechanics when solved a classical problem with it, these facts push the technology to discover and implement the quantum illumination, this discovery made a huge change in sensing theory, moreover, the implemented such as phenomena with a classical radar, make a play role in detecting strategies in sensing the stealth objects (whatever be an aircraft or drones), even more, the quantum radar can detect in an efficient way and more accuracy the natural debris outside the atmosphere, also, the quantum radar can work even though, in nosy, foggy, and high-temperature environment, all these features make the quantum radar promising emerging technology deserve to develop and enhanced in theoretical and technical ways. this paper provided a short analysis study to the most common types of quantum radar showing their cons and pros and could be used either in civil or military fields.
The quantum computing began with the concern of Richard Feynman to simulate the non-classical physical theories, Shor's algorithm showed the power of the quantum mechanics when solved a classical problem with it, these facts push the technology to discover and implement the quantum illumination, this discovery made a huge change in sensing theory, moreover, the implemented such as phenomena with a classical radar, make a play role in detecting strategies in sensing the stealth objects (whatever be an aircraft or drones), even more, the quantum radar can detect in an efficient way and more accuracy the natural debris outside the atmosphere, also, the quantum radar can work even though, in nosy, foggy, and high-temperature environment, all these features make the quantum radar promising emerging technology deserve to develop and enhanced in theoretical and technical ways. this paper provided a short analysis study to the most common types of quantum radar showing their cons and pros and could be used either in civil or military fields.
Quantum illumination (QI) and quantum radar have emerged as potentially groundbreaking technologies, leveraging the principles of quantum mechanics to revolutionise the field of remote sensing and target detection. The protocol, particularly in the context of quantum radar, has been subject to a great deal of aspirational conjecture as well as criticism with respect to its realistic potential. In this review, we present a broad overview of the field of quantum target detection focusing on QI and its potential as an underlying scheme for a quantum radar operating at microwave frequencies. We provide context for the field by considering its historical development and fundamental principles. Our aim is to provide a balanced discussion on the state of theoretical and experimental progress towards realising a working QI-based quantum radar, and draw conclusions about its current outlook and future directions.
Quantum radar has emerged as a promising sensing paradigm that exploits quantum resources, including entanglement and quantum correlations, to enhance target detection in noisy and lossy environments. Although entanglement generated by superconducting devices such as Josephson parametric amplifiers, Josephson parametric converters, and Josephson traveling-wave parametric amplifiers is rapidly degraded under realistic propagation conditions, the remaining quantum correlations can still provide a measurable detection advantage through the principles of quantum illumination. This review presents a comprehensive engineering perspective on quantum radar, covering the theoretical foundations of quantum illumination, microwave entanglement generation, electro-optomechanical quantum transducers, atmospheric channel effects, cryogenic receiver architectures, and digital signal-processing techniques. Recent microwave experimental demonstrations are also reviewed, highlighting the transition from theoretical concepts to laboratory-scale implementations. Collectively, these developments demonstrate that microwave quantum radar is evolving toward practical sensing architectures while emphasizing the engineering challenges that must be addressed before real-world deployment.
The aim of this paper is to evaluate the role of Quantum Radar in strengthening India's air defence architecture by addressing the limitations of classical radar systems against stealth and low-observable aerial threats. Air defence in the 21st century is characterised by a continuous contest between detection and evasion. While modern radars have evolved through digital beamforming, phased arrays, and frequency agility, stealth technology—through shaping, radar-absorbent coatings, and signature management—has reduced aircraft radar cross-section to unprecedented levels. For India, facing a two-front threat from technologically advanced adversaries, reliable detection of stealth aircraft, cruise missiles, and UAVs is a strategic necessity. Quantum Radar, based on Quantum Illumination principles, utilises photon entanglement and correlation to detect low-RCS targets even in high-noise and jamming environments. This paper presents a comparative evaluation of Quantum Radar with India's indigenous radar systems and examines engineering implementation prospects under the National Quantum Mission. A phased roadmap is proposed to integrate photonic and quantum sensing technologies within the Integrated Air Defence System, enabling future-ready, quantum-resilient surveillance and target acquisition capabilities for the Indian Armed Forces.
Quantum Illumination is the phenomena where defense contractors, scientists, quantum engineers and photonics experts have pondered it as the solution for correction method and for the effects of atmosphere on entanglement, causing atmospheric coupling, bringing the quantum system to its final phase; quantum decoherence.Rather than discard the tactic, large sums of money have been poured into strategies such as improving target detection in an effort to make quantum illumination efforts more efficient, or attempting to achieve quantum illumination using Gaussian states whereby quantum harmonic oscillators adopt states resembling the oscillatory behavior of a classical harmonic oscillator.So far the progress of a deployable quantum radar has not quite been achieved due to this same obstacle, quantum decoherence.This study proposes the solution for developing a military quantum radar whereby quantum decoherence due to quantum illumination to overcome the effects of atmosphere coupling on the quantum radar's quantum entangled photons.
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.
Stealth planes currently go under the radar, figuratively speaking, but maybe the higher definition promised by quantum radars could be used to expose them. Radar technology has become an ever more important tool in warfare since the Second World War, used to monitor the electromagnetic spectrum to detect and track enemy aircraft, missiles, satellites and other systems that in turn have grown more sophisticated in evading detection. Building better, more sensitive and harder-to-detect radar systems remains a key focus for defence manufacturers today, especially since in October 2018 the US Navy designated the electromagnetic spectrum as a warfighting domain on par with sea, land, air, space and cyber. Last year, China's biggest defence electronics company, state-owned China Electronics Technology Group, announced it had developed a next-generation quantum radar system' that, it claimed, can detect ballistic missiles and other objects flying at high speed through space. Two years previously, the group said it had tested a quantum radar to a range of 100km (60 miles). The expectation is that quantum radar, due to the unique behaviour of quantum entanglement, could, among other things, 'un-stealth' aircraft by detecting objects with a greater level of accuracy than conventional radar. Therefore, if China's announcement is true - and it hasn't provided any evidence to back its claim - it would be a huge win for both its defence and quantum capabilities.