QO-100 - PA protection

Based on the publication of Matthias, DD1US, I bought from him one of these TMT H3930 isolators - Thanks Matthias for supporting the community!!!

Here are my measurements taken with my miniVNAtiny and vna/J 3.4.8:

S21 S21

S12 S12

S11 S11

S22 S22

For reference, here the naming of the measurement (from wikipedia):


S11 - Input matching at transmitter side - worst SWR is 11.2:1 @ 2.4GHz

S22 - Input matching at antenne side

S21 - Transmission loss from transmitter to antenna

S12 - Isolation from antenna to transmitter