Silicon-photonic-chip-based microwave photonic radar for simultaneous range and azimuth measurement

This study presents a silicon photonic chip-based microwave photonic radar capable of simultaneous range and unambiguous azimuth measurement. The system employs a cascaded architecture comprising a Mach-Zehnder modulator (MZM) and an asymmetrical dual-drive Mach-Zehnder modulator (DDMZM). The MZM generates a broadband (14–16 GHz) linear frequency modulated signal through photonic frequency-doubling. The asymmetrical DDMZM converts the received phase-modulated echoes into intensity modulation via its amplitude-frequency response, producing two de-chirped signals and their frequency difference. Target range is derived from the frequency of the de-chirped signals, while the target azimuth is obtained from the frequency difference between the two de-chirped signals. Additionally, a fixed-length RF cable is introduced between the two receivers to establish a reference frequency, facilitating unambiguous angular measurement.