QAs AD6636_multiple channel Filter design.docx shown, it describe how to combine
the filtering resources of multiple channels. And here two channels' example is
1. For the RCF filter of one channel, I think we can use Softcell to design it,
2. If there are 6 channels, which value should be programmed into Decimation
Phase Bits of 6 channels?
AYou can use softcell to design your filter using multiple channels. Set
softcell up for your design just as you normally would and then just reduce
your output rate by a factor of two each time you double the number of
channels. I have attached a filter file showing the recommended method to use
multiple channels to implement a filter. In this example the filter would
have a 122.88MHz input rate and a 7.68MHz effective output rate. However,
since I’m planning to use 4 channels the output rate that I use in softcell is
1.92Mhz. This allows softcell to use more taps to generate the filter. I then
need to decimate by the amount of channels I plan to use in the CRCF (or DRCF)
filter – so in this case I decimate by 4 in the CRCF.
Once you get you filter in the part we normally split the channels at the
intermediate data router. We then decimate by a multiple of the number of
desired channels in the DRCF or CRCF (in this case by 4in the CRCF) and use the
decimation phase to delay the channels. Take a look at the filter and let me
know if you have additional questions.