LTE Band 25/41 Diplexer

Hi All,

I'm looking for a diplexer for the above LTE bands, ideally an off the shelf SAW/BAW type. I've searched the usual suspects websites (Qorvo/triquint, Avago, TDK, Johanson) but with no luck.

If I can't find something then it's back to the drawing board and first principles! Any tips for diplexer design at around 2.5 GHz? The most popular solutions seems to be 2 singly-terminated butterworth filters joined at a common port. But even with a 9th order filter I only get about 8dB adjacent channel rejection. The channel seperation/guardband is 500MHz between Band 25 and 41.

I don't really want to fork out SSS for a custom cavity filter either!

Any help greatly appreciated.

Thanks,
myRF