There is no LNA or receive filter on this ceramic patch antenna (GBP 5.00 shipping) in
Norristown, US L-band Antenna, Ceramic Patch 6 dBi Gain, RHCP, Inmarsat Std-C | Iridium Network It’s RHCP, as you need. There’s 5 days left on it.
Have you checked out this article? L-band patches are really not that difficult to build. It’s mostly cutting some metal parts, assembling them with some spacers and some soldering to an SMA connector.
Finally, I have one that I’ve never used. I can send it to you. If you are interested, message me.