Re: [Discuss-gnuradio] XCVR2450 Band Pass Filters & Frequencies

[Josh Blum]

On 07/01/2012 03:58 AM, Michael Hill wrote:
> The XCVR 2450 covers frequencies around 2.4 GHz and 2.5 GHz and also 4.9 to
> 5.9 GHz.
> 
> When running uhd_usrp_probe it said 2400 to 2700MHz!
> (E.g. I assume hardware performance drops off above 2.4 GHz but any reason
> why it didn't cap my frequency at 2400MHz?)
> 

I see probe printing 2.4 to 6.0. Maybe you are looking at a different
board? Can you send the output of uhd_usrp_probe.

> 
> http://code.ettus.com/redmine/ettus/documents/12
> Also I'm definitely not a hardware designer but I've been looking at the
> XCVR2450 datasheet and it seems there is a 2.45 GHz band pass filter for
> the lower frequency receiver pass (but none for the higher one..) and also
> for the transmit pass there is a 5.5GHz band pass filter for the higher
> frequency transmit pass but not the lower one, How come this is the case?
> 

Probably a design recommendation from maxim, or something we empirically
determined.

> E.g. If I wanted to reduce my unwanted image frequencies etc around 2.4 to
> 2.5 GHz, could I get another BP filter of the same type and just externally
> filter before transmitting to the antenna?
> 

Yes, definitely. Also see:
http://files.ettus.com/uhd_docs/manual/html/dboards.html#xcvr-2450

-Josh