M3933/30-33S Replacement: 32AS102-K20S3, SA3R-20

Original Part

M3933/30-33S

Amphenol SV Microwave

RF Attenuators 20dB 0 Hz ~ 32 GHz 50 Ohms 2W SMA In-Line Module

Alternative Part

32AS102-K20S3

Rosenberger

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

SA3R-20

Fairview Microwave

RF Attenuators 20dB 0 Hz ~ 3 GHz 50 Ohms 2W SMA In-Line Module

1. Substitution Conclusion for 32AS102-K20S3 The 32AS102-K20S3 is a viable substitute for the original part number M3933/30-33S under specific conditions, but with a critical limitation. Both units are fully matched in their core specifications: attenuation value (20dB), power handling (2W), and connector interface (SMA). The primary technical discrepancy lies in the operational frequency range. The original part covers DC to 32 GHz, whereas the 32AS102-K20S3 is limited to DC to 18 GHz. If the target application system operates below 18 GHz, this part can be considered a qualified direct replacement. However, for any application requiring operation within the 18 GHz to 32 GHz band—such as certain segments of millimeter-wave front-ends or high-end test and measurement systems—this substitute is unsuitable due to its insufficient frequency ceiling. Its use in such scenarios would result in inaccurate attenuation, increased insertion loss, or potential resonance within that band, leading to degraded or failed system performance.

2. Substitution Conclusion for SA3R-20 The SA3R-20 is generally not a qualified substitute for the original M3933/30-33S. The most fundamental and insurmountable technical difference is, again, the frequency range. While both share identical attenuation, power rating, and connector type, the SA3R-20 has a rated maximum operating frequency of only 3 GHz, compared to the original's 32 GHz. The SA3R-20 can only guarantee its specified performance up to 3 GHz. When used in applications exceeding this frequency—particularly into microwave bands such as 6 GHz, 18 GHz, or beyond—its actual attenuation will deviate significantly from the nominal 20dB. Furthermore, its Voltage Standing Wave Ratio (VSWR) will degrade sharply, and it may introduce unpredictable insertion loss and phase variations. This would cause severe performance degradation of the entire RF link. Consequently, this component is suitable only for low-frequency applications (e.g., UHF and below) and is not a viable replacement for mid-to-high frequency or microwave applications.

Analysis ID: 8E47-7BB8000

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