SA26B-20 Replacement: FMAT7466-20, SA3SR-20

Original Part

SA26B-20

Fairview Microwave

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

Alternative Part

FMAT7466-20

Fairview Microwave

RF Attenuators 20dB 0 Hz ~ 12 GHz 50 Ohms 2W SMA In-Line Module

SA3SR-20

Fairview Microwave

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

1. FMAT7466-20 Substitution Conclusion Whether the FMAT7466-20 can substitute for the SA26B-20 depends entirely on the final operating frequency of the application circuit. The two parts are consistent in attenuation value, power handling, impedance, and interface type. However, the frequency range of the FMAT7466-20 (0-12 GHz) is significantly narrower than that of the original part (0-26 GHz). If your system or test signal frequency exceeds 12 GHz, using the FMAT7466-20 will cause its attenuation performance to deviate severely from the nominal value (20dB). This introduces unacceptable insertion loss and return loss, leading to degraded system performance or measurement errors. Therefore, substitution is not viable in this scenario. If the operating frequency is confirmed to be below 12 GHz, it can serve as a lower-frequency substitute. However, special attention must be paid to its connector interface orientation (Jack-Plug), which may be reversed compared to the original part (Plug-Jack). This may necessitate the use of an adapter or a change in cable connection direction during installation.

2. SA3SR-20 Substitution Conclusion The SA3SR-20 is generally unsuitable as a substitute for the SA26B-20, except in extremely limited low-frequency applications. The most critical technical discrepancy is its drastically reduced frequency range (0-3 GHz), which is only about one-tenth of the original part's range (0-26 GHz). Across the vast majority of microwave bands above 3 GHz, the SA3SR-20 will fail to provide effective and accurate 20dB attenuation. Its performance will degrade sharply, completely failing to meet the original design's requirement for attenuating high-frequency signals. Unless it can be confirmed with absolute certainty that the entire system's operating frequency will never exceed 3 GHz, proceeding with this substitution carries significant performance risk. The conclusion is that it is not a viable substitute.

Analysis ID: D230-A3B4000

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