[Discuss-gnuradio] Low-cost hardware options

[Marcus D. Leech]

I've posted my latest thoughts at:

http://www.sbrac.org/files/digital_receiver2.pdf

This version has some BOM cost estimates for most of the items, and 
shows a new
  PLL, the ADF4351, which is a new chip from AD, coming out later this 
spring, which
  is pin compatible with the ADF4350, and includes a lower minimum 
output frequency, which
  means extending the range downwards to about 18MHz from about 68MHz. 
 Cool.

Going to a AD6652 (which has built-in DDC and CIC decimators) increases 
the price of the
  ADC by a factor of 3, but it would eliminate the need for a FPGA on 
the "host interface"
  side of that FMC connector.  So, you're trading a more expensive 
digital-receiver section
  for a cheaper "host interface" section.  For example, by using an 
AD6652, one could
  easily conceive of nothing more than a cheap EZ-FX2 USB-2.0 
implementation on
  the host-interface side.

For at least USB-3.0 and 1GiGe, you pretty-much *need* an FPGA on the 
host-interface board
  to do all the relevant protocol goop anyway, so perhaps making that 
FPGA large enough
  to do DDC and CIC decimation as well as the "host interface goop" is 
the right trade-off.

Love to hear more opinions

--
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org