Photonic Radar Images Small Objects

Researchers have developed a photonic radar system called photonic wideband stepped-frequency (P-WSF) radar system that detects an object’s location, speed, and angle down to the millimeter level. It could be used for applications including autopilot assistance, gesture identification, environmental sensing, and medical imaging. Tests showed that the system successfully handled a broad range of frequencies without requiring high-speed electronics.

The photonic radar system generates high-resolution images in a format that is simpler and potentially less expensive than conventional electronic radar systems. The system uses analog photonic generation and processes ultrawideband signals using only megahertz (MHz)-level electronics for detection and imaging. It synthesizes stepped-frequency (SF), continuous-wave radar signals using a frequency-shifted optical modulation that is driven by a low-frequency electronic oscillator.

The optical mixing of a broadband radar signal and its echoes at the receiver produces a demodulated signal with a bandwidth that is much smaller than the frequency step. This signal could be processed by low-bandwidth devices with high precision to enable real-time radar ranging and imaging.

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