Research On The Target Scattering Characteristics For Quantum Radar

Quantum radar is a new target detection technology based on the quantum physics theory, which is of great significance for both scientific and applied purpose. In this thesis, we mainly focus on the study of target scattering characteristics for quantum radar. The main contents include: exploring the target detection mechanism of quantum radar and the radar operation principle, studying the interaction mechanism between quantum radar and the target, investigating the QRCS characteristics of typical calibrators. The work can benefit the signal and receiver design, quantum radar target detection and recognition, as well as the design of quantum stealth targets.In the introduction part, the research background and significance are firstly illuminated. Secondly, the study progress of quantum radar and quantum radar target characteristics is overviewed. Thirdly, the main work and thesis structure arrangement are presented.In Chapter 2, the target detection mechanism of quantum radar is introduced based on the definition of quantum radar. Also, the theoretic research and realization of quantum radar are summarized. Subsequently, the performance comparison of target detection between quantum radar and traditional radar system is performed based on the two typical models, namely, quantum illumination radar(QIR) and interferometric quantum radar(IQR). Results show that bigger echo signal-to-noise ratio and better target detection performance can be obtained as entangled photons exploited to detect targets. Analyses of target detection mechanism and performance of quantum radar can support the research of quantum radar cross section in the next section.In chapter 3, signal photon wave function of quantum radar is derived firstly. Secondly, based on quantum electrodynamics(QED) theory, mathematical description models of the interaction between quantum radar and the target are established. Finally, quantum radar equation is obtained and the influence of QRCS on target detection performance is analyzed. Theory analysis and numerical simulation results demonstrate that the echo signal-to-noise ratio becomes larger and the corresponding target detection performance gets better with the increase of QRCS values.In chapter 4, a modified analytical expression of QRCS is derived. Based on the derived expression of QRCS, analytical description models of the sphere, plate, cylinder and corner reflector targets are established. How QRCSs of typical calibrators change as a function of the incident angle is studied by simulation experiments. Factors, such as radar operation distance, interatomic distance, target size and signal photon circular frequency, which can influence the values of QRCS are analyzed.Simulation results demonstrate that values of QRCS are independent of the radar operation distance and values of QRCS are independent of the interatomic distance when interatomic distance is far less than signal wavelength. When the incident signal contains two or more photons, the main lobes of QRCSs for the plate and cylinder targets become narrower and higher, and the side lobes lower. Compared to traditional radar cross section(RCS), QRCS and RCS for sphere, plate and cylinder targets play in a similar change law. However, for corner reflectors, QRCS are distributed more evenly than that of RCS.In the last part of the thesis, the research work is summarized and directions of the future work are provided.