I looked at the BBPD design so that we could make a POP22/110. It looks like it will be easy (I hope).

 The first attachment shows the schematic with the RF notch modified to handle 55 MHz. As long as the capacitor in this notch can be kept to below 20 pF, it doesn't degrade the noise so much,

The second attachment shows the TF and input referred noise. We ought to be able to get 20 pA/rHz at the input to the first RF amplifier.

The LISO files are in the svn under liso/examples/aLIGO_BBPD/,

Later, if we have to notch more than just 55 MHz, we can add a notch between the 2 RF amplifiers as Koji has done for the REFL165.