1. AT-109V Substitution Conclusion Based on core electrical parameters (9 dB attenuation, DC-18 GHz frequency range, 50 Ω impedance, 2 W power handling) and mechanical interface (SMA inline module), the AT-109V is fully identical to the original part LCAT1006-09. It can serve as a direct replacement in most general-purpose laboratory, test, or communication applications. The differences lie in the manufacturer and potential "non-quantifiable" metrics: as a premier connector manufacturer, Hirose products typically offer superior connector durability and consistency. However, this specific part is not explicitly marked as compliant with military reliability standards such as MIL. In extreme environments (e.g., high vibration, wide temperature cycling) or applications with stringent military/high-reliability requirements for long-term stability and lot-to-lot consistency, its suitability requires further validation. For standard commercial applications, the substitution risk is very low.