Hi Stefan,
The 32k sample limit is from the internal memory in the FPGA. The ADC12D1800RFRB has no on-board memory, but there is an option to stream data off the board continuously and make a deeper capture, which is with the HPC FMC connector. For your application, the data capture must be continuous, so multiple 32k samples will not work. There are a couple options for capturing this data.
1. We make an FMC-to-logic analyzer probe passive adapter card "ADCRF2LA". Provided you have an Agilent logic analyzer and probes, you can take a memory capture as deep as the memory on your logic analyzer:
http://www.ti.com/tool/adcrf2la
2. You can use any other memory capture platform to make a deeper memory capture. For example, we have support for the Xilinx ML-605, which also connects to the FMC connector and has on-board memory for the deeper capture. You can download the project from here:
Kind regards,
Marjorie