check pcb007 website for signal integrity book. Best of luck.
jk
On Sep 4, 2017, at 10:18 AM, Ricardo Moncaglieri wrote:

> Estimated colleagues,
> Nice to get in contact again with all of you after a bit long time.
> We are deploying a RF design and by first time we intend to use a  
> multilayer pcb with different substrat thickness as shows the stack- 
> up herebelow detailed.
> Questions here are:
> As per your experience, is it recomendable such a kind of substrat  
> design?
> Some pcb provider reported it is very difficult to achieve. Can you  
> recommend or share your background about pcb provider who can  
> assure high reliability on this pcb provision?
> Keep awaiting for your unvaluable feedback.
> brgds, Ricardo
>
> Ricardo Moncaglieri
> QA Electronic Service Manager
> INVAP SE
> www.invap.com.ar