[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Discuss-gnuradio] Bandwidth of XCVR 2450 Daugtherboard

From: Marcus D. Leech
Subject: Re: [Discuss-gnuradio] Bandwidth of XCVR 2450 Daugtherboard
Date: Wed, 28 Sep 2011 14:36:10 -0400
User-agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:7.0) Gecko/20110922 Thunderbird/7.0

On 28/09/2011 2:32 PM, Konstantinos wrote:
Thanks for your reply.

However, I am a little bit confused since in your reply you mention that these
are programmable low-pass filters which operate at baseband, while in the code
the associated comment says that this is the bandwidth of the bandpass filter on
the board. Secondly, why are these baseband filters? These are on the
daughterboard so I would expect them to operate on the intermediate band, since
the daughterboard converts complex IF to Real RF. Please let me know where I get
this wrong.

Thank you for your time again.



Most of the daughtercards convert to/from complex-baseband to/from real RF. The analog filters operate at baseband, and are therefore
  low-pass filters.

There are exceptions--the TVRX and TVRX2 use a non-zero IF. But all the other daughtercards use complex-baseband.

So, in complex baseband, if you want a total bandwidth of 40MHz, what you're actually asking for is -20Mhz to +20Mhz. Which means that
   I and Q are both low-pass filtered to 20MHz.

reply via email to

[Prev in Thread] Current Thread [Next in Thread]