This simulation-based study evaluates a DC-bias-free-at-the-electrode \(18\times \) polarization-modulator (PolM) photonic millimeter-wave source as a radio-over-fiber (RoF) system-performance case study. The optical front-end follows the reported three-branch PolM architecture; the contribution is the system-level evaluation of its spectral, eye-diagram, BER-related, and tolerance behavior rather than a new frequency-multiplication topology. A provenance-aware workflow is used to separate archived full-system simulation outputs, deterministic post-processing, analytical sensitivity analysis, and assumption documentation. The primary evidence base is a 24, 550-trace Monte-Carlo archive at 2.5 Gb/s OOK, from which eye-diagram statistics, exported BER-related outputs, OSNR \(_{est}\) , Q-factor, and composite quality indicators are reconstructed. The analysis benchmarks SQ ag \(_z\) ainst Q-factor and combined decision models using the direct 2.5 Gb/s OOK archive. Q-factor remains the strongest single classification indicator in the Q-positive diagnostic subset (AUC = 0.8336), while SQ \(_z\) is retained as a diagnostic multi-impairment score rather than as a Q-factor replacement. At a conservative SQ \(_z\) threshold, the false-optimistic rate is lower than for Q-only decisioning (0.1090 versus 0.2872), and 83.0% of high-Q failure cases are flagged by SQ \(_z\) . Direct fiber-span aggregation also moderates the deployment interpretation: the best 0.5-km bin is 4.50-−5.00 km with pass fraction 0.426, and no 0–25 km bin satisfies the adopted 95% pass-fraction rule. Phase-noise/linewidth and residual-sideband effects are included only as explicitly bounded synthetic-sensitivity or analytical-extension analyses. The resulting framework provides a transparent simulation-based protocol for evaluating DC-bias-free-at-the-electrode PolM RoF sources, while experimental verification, counted-error BER exports, standardized OSNR-bandwidth metadata, direct full-system 10/25 Gb/s validation, phase-noise, linewidth, and sideband-resolved validation remain necessary next steps.
