Photonics-Based Simultaneous DFS and AOA Measurement System without Direction Ambiguity

A novel scheme that can simultaneously measure the Doppler frequency shift (DFS) and angle of arrival (AOA) of microwave signals based on a single photonic system is proposed. At the signal receiving unit (SRU), two echo signals and the reference signal are modulated by a Sagnac loop structure and sent to the central station (CS) for processing. At the CS, two low-frequency electrical signals are generated after polarization control and photoelectric conversion. The DFS without direction ambiguity and wide AOA measurement can be real-time acquired by monitoring the frequency and power of the two low-frequency electrical signals. In the simulation, an unambiguous DFS measurement with errors of +/- 3 x 10(-3) Hz and a -90 degrees to 90 degrees AOA measurement range with errors of less than +/- 0.5 degrees are successfully realized simultaneously. It is compact and cost-effective, as well as has enhanced system stability and improved robustness for modern electronic warfare systems.

Automated summary

This paper proposes a novel scheme that can simultaneously measure the Doppler frequency shift (DFS) and angle of arrival (AOA) of microwave signals based on a single photonic system. By modulating two echo signals and the reference signal using a Sagnac loop structure and sending them to the central station (CS) for processing, the DFS without direction ambiguity and wide AOA measurement can be acquired in real-time. In the simulation, an unambiguous DFS measurement with errors of +/- 3 x 10(-3) Hz and a -90 degrees to 90 degrees AOA measurement range with errors of less than +/- 0.5 degrees are successfully achieved simultaneously. This scheme is compact, cost-effective, and improves the system stability and robustness for modern electronic warfare systems.