Quantum Radar: An Engineering Perspective

Quantum radar has emerged as a promising paradigm that utilizes entanglement and quantum correlations to overcome the limitations of classical detection in noisy and lossy environments. By exploiting microwave entanglement generated from superconducting devices such as Josephson parametric amplifiers, converters, and traveling-wave parametric amplifiers, quantum radar systems can achieve enhanced detection sensitivity, lower error probabilities, and greater robustness against thermal noise and jamming. This review provides a comprehensive overview of the field, beginning with the theoretical foundations of quantum illumination and extending to the generation of entanglement in the microwave regime. We then examine key quantum radar subsystems, including quantum transducers, amplification chains, and receiver architectures, which form the backbone of practical designs. Recent experimental systems are surveyed in the microwave domain, highlighting proof-of-principle demonstrations and their transition from conceptual frameworks to laboratory realizations. Collectively, the progress reviewed here demonstrates that quantum radar is evolving from a theoretical construct to a practical quantum technology capable of extending the performance boundaries of classical radar.