11‐GHz‐Bandwidth Photonic Radar using MHz Electronics

Abstract

AbstractThe ever‐increasing demand for high resolution and real‐time recognition in radar applications has fuelled the development of electronic radars with increased bandwidth, high operation frequency, and fast processing capability. However, the generation and processing of wideband radar signals increase the hardware burden on complex and high‐speed electronics, limiting its capability for applications that demand high spatial resolutions. Progress is being made, photonics‐assisted radars offer higher frequencies but still heavily rely on costly and sophisticated high‐frequency electronic devices such as benchtop digital microwave waveform generators that fundamentally constrain the bandwidth and the practical utility. Here, for the first time, a photonics‐based radar with >11 GHz bandwidth (exceeding 20 GHz without RF antenna bandwidth limitation) driven and processed by simple MHz‐level‐electronics‐based acoustic‐optic modulation is demonstrated, which radically eliminates the requirement for ultra‐fast GHz‐speed electronics for wideband radar signal generation and processing. This wideband radar achieves centimeter‐level spatial resolution and a real‐time imaging rate of 200 frames s−1, allowing for high‐resolution detection of rapidly moving blades of an unmanned aerial vehicle. This radar provides an important technological basis for next‐generation broadband radars with greatly reduced system complexity essential to ubiquitous sensing applications such as autonomous driving, environmental surveillance, and vital sign detection.