Regarding layout consideration for cascade amplifier chain

[Maitry07]

Hello support Team,

I am planning to use 2 cascade IF gain block amplifiers in my RF front end chain before RF-ADC . and I have 4 simultaneous ADC for which I am planning to use 4 similar RF Front end at the input of 4 RF-ADC inputs.

So, What would be the feasible option to have All 4 similar RF Front end cascade amplifiers chains in single PCB or to have 4 different PCB for each individual RF-ADC input channels? In order to have the highest possible isolation between the channels.
I have attached the block diagram for your reference.

As My RF-ADC has proper isolation between the near channels. But In order to have a highest possible isolation between the RF Front end chains-4 similar. What consideration needs to be done.
Note: My all 4 RF inputs having same frequency but different amplitudes.

kindly suggest your views and guidance.

 

[mtwieg]

For "highest possible isolation," standard practice it to put each receiver in its own zip code.

For more specific guidance, need more specific info on your requirements. 60dB? 80dB? 100dB? Frequency/bandwidth? Keep in mind there's no point in having isolation in great excess of the dynamic range of each receiver.

 

[Maitry07]

Hello ,

My frequency band is IF: 35-61 MHz and at a specific time, the signal bandwidth would be +/-1 MHz.
All channels input will be simultaneous with the same source. So frequency would be same but amplitude would be different. So, that's why I am thinking for having isolation of 80 dB between near by channels.

My ADC inputs near by channels are having very good isolation upto 90 dB , but as I will be using the Front end amplifier chain in each individual channel, So, I think, there may be a requirement of having isolation between near by channels.
Kindly provide your views.