1. FMAT7620-1 Substitution Conclusion The FMAT7620-1 is identical to the original SA26B-01 part in core electrical parameters—including attenuation value, power handling, and impedance—as well as in mechanical footprint. Therefore, for applications operating at frequencies up to 18 GHz, it serves as a fully viable drop-in replacement for the SA26B-01. The most critical distinction lies in the frequency range: the original part is specified up to 26 GHz, whereas the FMAT7620-1 is only guaranteed to perform up to 18 GHz. In systems operating between 18 GHz and 26 GHz, substituting with the FMAT7620-1 may lead to performance degradation, such as reduced attenuation accuracy and increased VSWR, rendering it unsuitable for replacement within this higher frequency band. However, if the system’s maximum operating frequency is clearly at or below 18 GHz, this frequency difference does not pose an issue, and the FMAT7620-1 can be safely used as a substitute.