How does DDC work and how its implement in satellite digital receiver?

[Nosheen]

hi,
i want to know the working of DDC and also its implementation in Satellite digital receiver to low down the micro wave frequencies to IF...
if anybody knows,kindly help me out.

regardz
Nosheen

 

[rajsrikanth]

Re: how DDC works???

ddc actually consists of a mixer and numerical controlled oscillator and a phase locked loop. and frequec synthesizer. in this the signal is demodulated in this process.
the incoming signal is taken and it is mixed with the sine and cosine functions with equal frequency of the carrier so from that we obtain the actual message signal.

hope clear
if need more help reply back again

with regards
raj

 

[mowgli]

Re: how DDC works???

Hello Nosheen,

if you are interested in how a DDC works you could take a look at some device's data-sheet and application notes. In the past I worked on the FW of a board equipped with a DDC by Analog Devices, the AD6624A: its data sheet is not very well organized (in my opinion the information necessary to set the configuration of the device are too fragmented in the document and not clearly described) but it is a good example to study from an architectural point of view, because it describes each functional block of the device.
Then you could read some application note to see how the device could be used in a TLC system.

Regards
Mowgli