A Photonic Approach for Doppler-Frequency-Shift and Angle-of-Arrival Measurement Without Direction Ambiguity

A Simple Photonics-Based Measurement Method for Microwave DFS and AOA

“…uring intelligent driving, radar detection, wireless communication, internet of things and other emerging fields, it is critical to determine the real-time location of moving objects [1][2], which involves doppler frequency shift (DFS) as well as angle of arrival (AOA) measurements [3][4][5][6]. DFS is the frequency shift between the back and come signals [7], and is applied to obtain the velocity of the object. The angle of the moving target can be estimated by AOA, which can be calculated through the phase difference between the echoes received by spatially-separated antennas [1][2][3][4][5][6][7].…”

“…DFS is the frequency shift between the back and come signals [7], and is applied to obtain the velocity of the object. The angle of the moving target can be estimated by AOA, which can be calculated through the phase difference between the echoes received by spatially-separated antennas [1][2][3][4][5][6][7]. However, the narrow bandwidth and poor stability of key electronic devices limit the application of traditional electrical systems.…”

“…However, as far as we know, many reported systems are used for measurement of either DFS or AOA, which limits the application of the systems and hard to fast obtain and the accurate location of the subject. To solve this problem, some photonics systems [2][3], [7], [26][27][28] have been proposed in the past 3 years.…”

Photonics-based Simultaneous DFS and AOA Measurement system Without Direction Ambiguity

“…It can perform the DFS measurement error less than 0.8 Hz and the AOA measurement error less than ±2.5° in a range from 3.2° to 81.5°, and it can be extended to a multi-channel system. In 2021, two simple photonics-based DFS and AOA estimation systems based on a polarization-division-multiplexed dual-drive Mach-Zehnder modulator (PDM-DMZM) [16] or a dual-parallel Mach-Zehnder modulator (DPMZM) [17] are implemented. Especially in [17], the phase ambiguity problem is solved and the AOA measurement range is from ±10° to ±90° with a measurement error of less than 5.5°.…”

“…In 2021, two simple photonics-based DFS and AOA estimation systems based on a polarization-division-multiplexed dual-drive Mach-Zehnder modulator (PDM-DMZM) [16] or a dual-parallel Mach-Zehnder modulator (DPMZM) [17] are implemented. Especially in [17], the phase ambiguity problem is solved and the AOA measurement range is from ±10° to ±90° with a measurement error of less than 5.5°. Whereas, an optical bandpass filter (OBPF) or a wavelength-division multiplexer (WDM) is required to select or separate the optical signals, restricting the operating range of the whole system.…”