schrieb Marcus D. Leech on 2011-01-15 03:10: > I've posted my latest thoughts at: > > http://www.sbrac.org/files/digital_receiver2.pdf
I like the design. With an USB2.0 interface it comes close to the FuncubeDongle. > 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. You have no host interface. Adding a host interface without FPGA results in the the need for hardware DDC/CIC. An FPGA would add in cost and complexity. One of the Digilent parts could be a starting host interface. A second step could be designing a OS host interface with FPGA, something could imagine quite a lot of people could find interesting. Maybe there are existing designs. Patrick -- Engineers motto: cheap, good, fast: choose any two Patrick Strasser <patrick dot strasser at tugraz dot at> Student of Telematik, Techn. University Graz, Austria _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
