Re: Synthesis Of WideBand Waveform

yogesh_gharote wrote:
Hi all!
I have a 400MHz bandwidth analog real waveform & I want to digitise
it using ADC. So i need to sample it at least at 800MHz. But I dont have a
suitable ADC to do that (I need to maintain a high dynamic range of around
75dB requiring a ADC chip of around 16bits which can sample at 800MHz or
more which i dont have). What i have instead is a 4 channel ADC which can
sample at upto 200MHz (each channel) . My question is can I sample the
wideband waveform using 4 channels simultaneously sampling at 200MHz (each
channel), something akin to quadrature sampling , and then combine the 4
channel streams to get back my original wideband waveform ? Is there any
tangible literature which states how this can be done? ( I have read most
of the basic sampling theorms papers which give information about higher
order bandpass sampling and interpolants but had a hard time understanding
them)So i am looking around if any of u guys have done this before.

Note: The wideband waveform which i have mentioned is bandpass waveform
centred around some freq fc>>400MHz

Probably not. First, you need to sample significantly faster 800MHz in a practical system. (800MHz is a theoretical lower bound under conditions that are ideal in several respects, none of them realized in practice.) Second, you would need to synchronize the ADCs' operations more precisely than their jitter and aperture uncertainty would likely allow.

Jerry
--
Engineering is the art of making what you want from things you can get.
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.

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