1. AT-109V Substitution Conclusion The AT-109V matches the original M3933/30-19S in all key parameters—attenuation (9 dB), power rating (2 W), impedance (50 Ω), and connector interface. However, its effective operating frequency range (0–18 GHz) is notably narrower than the original’s 0–32 GHz. If the target application operates below 18 GHz, the AT‑109V can serve as a viable drop‑in replacement. For systems requiring operation between 18 GHz and 32 GHz—such as in 5G millimeter‑wave, high‑end test instrumentation, or satellite communications—the AT‑109V lacks sufficient bandwidth and should not be substituted. Using it in such cases could lead to excessive signal loss, degraded performance, or even equipment damage. Additionally, while both Amphenol and Hirose are reputable manufacturers, switching from Amphenol to Hirose may introduce subtle variations in performance consistency at ultra‑high frequencies; validation under actual application conditions is recommended.