Ultra-high resolution radar imaging based on microwave photonics

High-resolution and real-time radar imaging is highly desired in applications such as pilotless automobiles, unmanned aerial vehicles, and quick security checks, where resolutions around centimeter or sub-centimeter are required. However, due to the limited bandwidth of the state-of-the-art electronic devices, it's difficult for electrical radar systems to obtain simultaneously real-time imaging and high imaging resolution. Thanks to the advantages of high frequency, large bandwidth, low transmission loss and electromagnetic interference immunity brought by the photonic technologies, microwave photonics is regarded as a promising solution to the high-resolution radar imaging. In this paper, we will review the recent advances in the development of photonics-based high-resolution imaging radars, overview the key technologies and discuss their potential applications.