Design and Test of a Photonic-Assisted Ultrawideband Receiver Based on Optical Subsampling

This article presents a photonic-assisted ultrawideband receiver architecture based on dual-parallel optical subsampling using two mode-locked lasers (MLLs) with distinct repetition rates. The proposed architecture resolves frequency ambiguity and suppresses aliasing without requiring a third optical link, thereby significantly reducing system complexity, size, weight, and power (SWaP). Carrier-suppressed single-sideband (CS-SSB) modulation is implemented using a dual-parallel Mach-Zehnder modulator (DP-MZM), while balanced coherent detection enhances noise suppression. Compared to conventional double-sideband (DSB) schemes, the system achieves a twofold increase in instantaneous processing bandwidth. Simulation and experiments demonstrate frequency measurement errors below 3 MHz across the 2–18-GHz band, with a measured spurious-free dynamic range (SFDR) of 107 dB$\cdot $Hz${}^{{2}/{3}}$. Fabricated in a 130-nm silicon photonics process, the receiver provides a compact, low-SWaP, and stable solution for wideband electronic reconnaissance.