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How can the bandwidth of 122-16 reach 550MHz?

Posted: Thu Nov 25, 2021 10:23 am
by gahangwong
It's max sample rate is 122.88Mhz, and the max bandwidth is 550Mhz, how could that happen? Is this a result of band-pass sample?
For example, if I want to sample the whole FM broadcasting band (87Mhz-108Mhz in China), what configuration should I do on hardware and software?

Re: How can the bandwidth of 122-16 reach 550MHz?

Posted: Thu Nov 25, 2021 11:38 am
by pavel
gahangwong wrote:
Thu Nov 25, 2021 10:23 am
It's max sample rate is 122.88Mhz, and the max bandwidth is 550Mhz, how could that happen?
I think 550 MHz is an analog bandwidth directly copied from the LTC2185 ADC datasheet.
gahangwong wrote:
Thu Nov 25, 2021 10:23 am
For example, if I want to sample the whole FM broadcasting band (87Mhz-108Mhz in China), what configuration should I do on hardware and software?
Sampling a 21 MHz frequency band with the 122-16 board is a little bit challenging.

I have a wideband SDR receiver that can sample two ~9 MHz frequency bands from both RF inputs:

https://github.com/pavel-demin/red-pita ... ide_122_88

It could be used to sample two ~45% parts of a 21 MHz frequency band.

Re: How can the bandwidth of 122-16 reach 550MHz?

Posted: Mon Feb 28, 2022 9:58 am
by redpitaya
That is the analog bandwidth because of no input filters. It is like this so users can add their own filters and preselectors, or to use it for undersampling
https://en.wikipedia.org/wiki/Undersampling