SA26B-20 Replacement: AT-120V, M3933/14-04S

Original Part

SA26B-20

Fairview Microwave

RF Attenuators 20dB 0 Hz ~ 26 GHz 50 Ohms 2W SMA In-Line Module

Alternative Part

AT-120V

Hirose Electric Co Ltd

RF Attenuators 20dB 0 Hz ~ 18 GHz 50 Ohms 2W SMA In-Line Module

M3933/14-04S

Amphenol SV Microwave

RF Attenuators 20dB 0 Hz ~ 12.4 GHz 50 Ohms 2W SMA In-Line Module

1. AT-120V Substitution Conclusion The AT-120V can serve as a conditional substitute for the SA26B-20. The key distinction lies in its upper operating frequency limit (18 GHz versus 26 GHz). If your application frequency does not exceed 18 GHz—such as in most 5G Sub‑6GHz systems, satellite communications below Ku‑band, or general microwave links—the AT‑120V provides full compatibility in attenuation accuracy, power handling, and interface specifications. However, for systems operating between 18 GHz and 26 GHz (e.g., certain K‑band communications or test setups), the AT‑120V is not suitable, as its attenuation performance may exceed tolerance limits or become ineffective in this higher frequency range.

2. M3933/14-04S Substitution Conclusion The M3933/14-04S is a more limited substitute for the SA26B-20. The primary difference is again a significantly lower upper frequency limit (12.4 GHz versus 26 GHz). It can only be safely used in applications within C‑band, X‑band, and lower frequencies—such as mid‑ to low‑band wireless communications and radar systems. For any system operating above 12.4 GHz (e.g., Ku‑band, K‑band, and above), this part cannot guarantee the specified 20 dB attenuation value. Uncontrolled insertion loss and impedance mismatch may be introduced, potentially degrading system performance. Therefore, it is not recommended for scenarios requiring the full frequency coverage of the original design.

Analysis ID: CF89-5823000

Based on part parameters and for reference only. Not to be used for procurement or production.