FPGA-Based Miniaturized Multi-Channel High-Precision Stabilization System for Lasers and Mach–Zehnder Modulators

Following the integrated optical assembly and single printed circuit board co-layout design concept for electrical circuits, this paper develops a field-programmable gate array (FPGA) based, miniaturized, eight-channel microwave photonic transceiver stabilization system for the joint regulation of lasers and Mach–Zehnder modulators (MZMs). The integrated single-board hardware enables high-precision, high-reliability automatic temperature control (ATC), automatic power control (APC), and arbitrary closed-loop control of the MZMs bias point, overcoming the drawbacks of discrete single-channel, independent control schemes reported in previous works, which lack expandability for large radar arrays. The laser sub-module supports continuously adjustable drive current and multi-level protection, achieving wavelength stability of 0.01 nm and an output optical power fluctuation of less than 0.02%. The MZM control unit delivers wide-range, high-stability bias drift suppression with arbitrary bias point stability up to 0.05 dB. All static and dynamic performance indicators of the proposed module are characterized using a dedicated experimental setup comprising optical power meters, optical spectrum analyzers, temperature cycling chambers, and vector signal analyzers. Leveraging FPGA-based parallel hardware logic, the system features low latency, low jitter, cross-channel mismatch compensation, and excellent timing synchronization, with a compact overall footprint of 180 mm × 120 mm that matches the size of radar antenna panels and supports flexible array scaling. The proposed integrated module meets the low-noise, high-reliability, and high-integration requirements of radio-over-fiber links in microwave photonic radars. It effectively advances the practical engineering deployment of microwave photonic radar systems.