How is "directivity" defined for these Minicircuits gain blocks? Datasheet here:
Across the bandwidth of interest I'm measuring S21 as about 20-something dB give or take a dB which seems fine, S12 is at -40.
If "directivity" in this context is just S12 then that seems within spec but if it's |S21 - S12| then something seems wrong with my setup and/or the amp.
Doing the measurements on a (unfortunately not my personal home-lab machine!) Keysight 5080.