ADD, Developing Radar to Detect Stealth

Quantum Remote Sensing Concept Diagram (Source: Agency for Defense Development)

[Agency for Defense Development]The quantum theory that emerged in the early 1990s is currently a field where leading countries such as the United States are researching various quantum phenomena to overcome the limitations of classical physics. Quantum technology is being intensively studied in various application areas linked to the 4th Industrial Revolution, including quantum computers, quantum sensing, and quantum communication. In particular, it is gaining attention as a disruptive technology that will lead new-concept future weapon systems through integration with the defense sector.

▲ Beyond the limits of conventional radar: ‘Quantum Radar’= Recently, methods to apply quantum phenomena occurring in the microscopic world to the macroscopic world we live in are gradually becoming concrete, especially among quantum technology powerhouses. China is leading the field of long-distance quantum communication by successfully demonstrating quantum communication technology based on entangled photon states between Austria and China using satellites. The United States has demonstrated quantum supremacy performance in limited areas such as quantum computing using dozens of superconducting quantum bits (quantum beat, qubit). Additionally, research results on quantum radar based on superconducting quantum devices have been presented at the laboratory level in Europe and the United States, and fundamental research on the detailed technologies of quantum radar is actively underway.

Quantum radar can revolutionarily increase the signal-to-noise ratio beyond the limits of conventional radar. Domestic research centered on the Agency for Defense Development is underway to secure the core technology of quantum remote sensing that can clearly detect low-observable targets by using ‘entangled photon pairs,’ the core of quantum radar, rather than unentangled photons. The main core technologies include quantum state generation for creating quantum information, storage of generated quantum information, bidirectional conversion between optical photons and microwave photons for long-distance quantum information transmission and reception, and precise measurement technology of quantum states.

▲ Quantum Magnetic Field Sensor= Quantum sensors are ultra-high sensitivity and ultra-high resolution implementation technologies that dramatically overcome the limitations of classical sensors, enabling measurement of values impossible with classical sensors or improving measurement precision.

In particular, quantum magnetic field sensors are widely used in the defense sector, including magnetic anomaly detectors (MAD) for submarine detection, harbor surveillance systems monitoring the entry and exit of vessels, and unexploded ordnance (UXO) detection equipment for detecting buried hazards underground and underwater.

Among these, atomic-based quantum magnetic field sensors can measure up to the quantum measurement limit and have the advantage of low-power operation. Therefore, advanced quantum technology countries are actively conducting research and development in the defense sector. The principle of this sensor is based on the fact that the Larmor frequency of atomic precession changes when an external magnetic field varies. By aligning the quantum axis using the internal energy levels of atoms and synchronizing atomic spins, the change in the Larmor frequency of atomic precession according to the external magnetic field strength is measured to accurately determine the magnitude of the external magnetic field. The core of the atomic-based quantum magnetic field sensor is an atomic cell that can be miniaturized to a few cubic millimeters, enabling sensor fabrication smaller than conventional sensors (Fluxgate) and allowing drone mounting due to reduced power consumption from miniaturization.

▲ Photon-based Microwave Radar= Conventional radar systems are being upgraded with multifunctionality and multi-frequency band systems. In particular, the quality of transmitted signals and modulation of operating frequencies are key to radar performance, with concentrated investment in developing signal sources that have excellent noise characteristics and can operate at high-frequency bands.

Existing RF signals are generated by electronic devices through multiple stages of frequency conversion to create signal sources in the operating frequency band. At each stage, noise from the signal source is introduced, and due to the characteristics of electronic devices, only specific frequency bands can be used. However, photon-based microwave technology has advantages such as broadband capability, resistance to electromagnetic interference (EMI), low loss, and low distortion. Using this technology eliminates the need for multiple frequency conversion stages in conventional radar, reduces noise introduction, and increases radar detection range and resolution with lower transmission power.

The Agency for Defense Development is conducting research on domestic development of key optical components and integration of radar signal generation and detection using domestic infrastructure. Furthermore, through active collaboration with the civilian sector, which is actively advancing in ultra-high-speed optical communication, it is expected that existing electromagnetic wave-based radar sensors can be replaced with photon-based microwave radar.

The Agency for Defense Development is preparing for the future through advanced defense science and technology research and development. It is striving to actively respond to future all-around threats by securing technological superiority in the quantum field and to develop quantum technology as a new game changer to drive the advancement of the national defense industry.

This content was produced with the assistance of AI translation services.