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

[Elvis Dowson]

Hi,

On Jul 9, 2010, at 7:53 PM, Brian Padalino wrote:

> You could try something like a switched filter bank as a preselector:
> 
>    http://www.spectrummicrowave.com/sfb.asp

I was thinking of a discrete SMT type component, which I can mount on a PCB 
board, those are really big. 

> That was something a quick google search found.  Unfortunately, your
> band-pass requirements are lacking.  What types of channel bandwidths
> do you want?  How many channels?  How much rejection are you looking
> for?

I was initially thinking of a BPF in the 400Mhz to 4000Mhz range. This would 
interface with a LNA of the same band-width. However, I would like to be able 
to digitally control the BPF, to be able to say filter frequencies, prior to 
sending it to the LNA, e.g. 1800Mhz to 2200Mhz, and then switch back to 400 to 
600Mhz, etc. 

Doing a google search, I came across FPAA (Field Programmable Analog Arrays), 
and I was wondering if using a switched bank of capacitors and resistors, would 
do the trick?

I found one company http://www.anadigm.com/

haven't gone into the details of an FPAA, but was wondering if someone else on 
this forum has looked into this type of thing before?

Could I potentially create my own externally switched capacitor & resistor 
network, under control of a standard FPGA, to achieve the same thing? 

Best regards,

Elvis Dowson