[SI-LIST] Transmission Line calculator Problem!

Hi all
 
I want to design diff Lines for carrying LVDS Signals(pulses with 100MHz and 
rise time of <1 ns) in form of Stripline and MicroStrip,but I have problem with 
calculating exactly their characteristic Impedance.
In both HyperLynx(from mentor) and Cadence Allegro(V16.2) (Transmission Line 
Calculator) I tryed to calculate this,but what I obtained in both is different 
with each other
 
I want to achieve 100 ohm for Zdiff, I derived (from formula and constraints)  :
                                                                Stripline :  
W=5 mil   S=5 mil    h$mil 
                                                                microstrip:  W 
mil  S=5 mil   h mil
                                                                           
dielectric : FR4
                                                                     copper 
thickness : 1.4 mil
 
for Stripline
 
HyperLynx : 85.5 ohm
Allegro      : 74.34 ohm
 
for  microstrip
 
HyperLynx  :97 ohm
Allegro       : 92.37 ohm
 
so What Should I do ? (for exactly calculating Z0) 
 
Thanks for Help
 
Best Regards
 
 
 

      
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