[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Discuss-gnuradio] Guide : what is the value of the IF converted bef
Marcus D. Leech
Re: [Discuss-gnuradio] Guide : what is the value of the IF converted before feeding the ADC in usrp/gnuradio
Tue, 12 Apr 2011 07:13:51 -0400
Mozilla/5.0 (X11; U; Linux i686; en-US; rv:22.214.171.124) Gecko/20101027 Fedora/3.0.10-1.fc12 Thunderbird/3.0.10
On 04/12/2011 04:44 AM, ton ph wrote:
> Hi everyone ,
> I would like to know what is the actual last converted IF frequency
> which is actually fed to the ADC in usrp/gnuradio , since ADC rate is
> 64MS/s , I hope it IF should be less than 2xSampling rate of ADC,
> which implies IF could not be 70Mhz. So what is the value of IF before
> entering the ADC and what speed rate does the baseband is fed to the
> ADC for samping.
> Thanks in advance and also i apologize for any errrormatic information
> in my post.
It depends on the daughtercard in use, but most daughtercards
down-convert the desired center
frequency to a complex baseband, centered at 0Hz.
There are execeptions. The original TV_RX used an IF of 5.75MHz, which
was converted to complex
baseband (I and Q) in the FPGA with a DDC.
Shirleys Bay Radio Astronomy Consortium