"recoder" <[email protected]> wrote in message
news:[email protected]..
> We have implemented a high speed qpsk demodulator in a FPGA
> demodulator board.
> Until now we fed the I and Q inputs from another board by wire.
> Now we are looking for an IF board that can take a 70 Mhz RF signal
> and output the I and Q signals to be fed to our FPGA board.
> Can anybody recommend one?
> Thanx in advance

There are several vendors of ADC+FPGA boards out there with a variety of
form factors. They primarily target the military and other specialty signal
processing markets, so they aren't generally cheap ($10k and up). Our
company has had good results with boards from ICS, Ltd. (now part of GE
Fanuc) and Pentek. I think Transtech has a family of FPGA boards with a
variety of daughter cards for I/O and ADC. Depending on your host platform,
a PCI, PMC, or PCI-Express board may be a good choice. Many of these support
multiple channels of ~200 MHz ADC's (what you need for 70 MHz RF unless you
want to deal with balancing quadrature sampling) feeding something like a V4
or V5 FPGA (significant part of the $$$). I wouldn't recommend rolling your
own interface board as getting the signal timing on all those ADC bits is a
bit tricky. That's why we tend to buy boards that have the ADC and FPGA
integrated together.

-Marty