Re: [Discuss-gnuradio] Programmable band-pass filters

[Elvis Dowson]

HI Marcus,

On Jul 9, 2010, at 9:36 PM, Marcus D. Leech wrote:

> You should know that any filter you place in front of an LNA needs to have a 
> ridiculously low insertion loss in to not severely degrade the noise figure 
> if the LNA
> 
> It's likely that any switchable filter will have unacceptably high insertion 
> loss
> 
> A better approach is to use a first LNA with modest gain and good OIP3 and 
> P1dB then your filters then another low noise stage

The following diagram represent the various stages for a direct conversion RF 
front-end.

Pasted Graphic.pdf
Description: Adobe PDF document

The part that I would like to make programmable are the 2 BPF stages before 
LNA1 and LNA2. 

Any suggestions?

Best regards,

Elvis Dowson