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

Abstract

This article put forwards a simple microwave photonics measurement method for microwave doppler frequency shift (DFS) and angle of arrival (AOA), which obtains the information conveniently and precisely by comparing the frequency and phase shift between two channels signals. The DFS direction can be judged more intuitively thanks to the introduction of the reference signal. The system uses two parallel dual parallel Mach-Zehnder modulators (DPMZMs) for carrier suppression single-sideband (CS-SSB) modulation. A proof-of-concept experiment was taken, showing that during ±100 kHz, the DFS measurement error is <±0.1 Hz over a 40 GHz frequency range as well as power sensitivity is down to -50 dBm. What is more, the measurement error of AOA is < ±1° from 0° to 90°. This simple system acquits excellent width band performance without the optical filter, providing a reliable and more conducive to humancomputer interaction solution for future measurement and sensing applications.

Photonic Measurement for Doppler Frequency Shift and Angle of Arrival Based on Integrated Dual-Parallel Dual-Drive Modulator

“…Recently, scholars have undertaken a lot of work on microwave photonic measurement technology. In the schemes of simultaneous measurement of DFS and AOA [6][7][8][9][10][11][12][13][14][15], by frequency downconversion, the DFS value is obtained from intermediate-frequency (IF) signals, and there are two main methods for determining the DFS direction. The first way is based on a reference signal with a frequency shift, which adds a small frequency shift to the transmitted signal [6][7][8][9][10][11].…”

“…In terms of AOA measurement, two main methods have gained widespread attention. The first way is to compare the phase relationship between the two generated electrical IF signals [10,[12][13][14][15], which can mostly be used for DFS direction determination simultaneously. The second method is to construct an amplitude comparison function (ACF).…”

A Simple Photonic System for DFS and AOA Simultaneous Measurement

“…Ref. [24] implements a simple link system by applying two dual-parallel MZMs, in which the DFS value can be directly detected while the DFS direction and AOA can be obtained by comparing the phase of the two down-converted signals. Moreover, the system needs an additional bias point control circuit to ensure the modulator is implemented in carrier suppression single-sideband status.…”