Here's my initial attempt at measuring a two port model of the LSB filter. I generated this quick 2 port model with the VNA when the filters arrived last week. Note that it only models the filter over a 20kHz span centred on 9MHz.
To get the forum upload tool to accept the file I've had to rename it from KVGXF9S43.s2p to KVGXF9S43.txt. So once it is downloaded it can be renamed to KVGXF9S43.s2p to make it load into a simulator easily. Hope it uploads OK.
The source and load that the filter sees needs to be the equivalent of about 1000 ohm in parallel with about 24pF to get a good match. See below for a first attempt at a matching network based on this VNA s2p file. Also a computer simulation of the filter once fed with this matching network. It looks like the insertion loss will be about 2.5dB.
You can load this KVGXF9S43.s2p two port model into RFSIM99 and create a matching network for it or try the one posted below in the RFSIM99 image. But the model is only valid over a 20kHz span so RFSIM99 would have to be set up for a 20kHz span
I'll try and find time to create a better two port model over the weekend as I think the stopband performance could be better than that shown in the quick and dirty simulation below. But I'll also build the matching network for real and test it. Note that the inductor used in the matching network will need to be adjustable in order to tune for a good passband response.