Why mutual inductance coupling is high in microstrip line

Status
Not open for further replies.

hioyo

Advanced Member level 4
Full Member level 1
Joined
Aug 18, 2021
Messages
116
Helped
0
Reputation
0
Reaction score
2
Trophy points
18
Activity points
899
Dear Team,

I was learning about crosstalk in PCB from the High-speed signal propagation book by Howard Johnson.
It says mutual inductance coupling is high in microstrip line compared to mutual capacitive coupling.
May I know why it is like that

Regards
HAri
 

Isn't that normal ? Distributed Inductance along Line Length and Magnetic Coupling due to this reason is dominate. Capacitive Coupling occurs at fringe sides of the Line and it's ( Electrical Coupling ) relatively low compare to Magnetic Coupling.
 
  • Like
Reactions: hioyo

    hioyo

    Points: 2
    Helpful Answer Positive Rating
Thank you...
May I know what you mean by fringe sides of the Line
 

Stripline impedance is vertical to ground plane with nH/mm and pF/mm such that a w:h ratio in FR4 of 2:1 is about 50 Ohms from Zo=sqrt(L/C) There is lateral flux coupling from coplanar tracks by M being a fraction of L and C due to the thin edge crosstalk which is about 50% of the voltage for a 0.1ns risetime (near 4GHz) when the geometry for l:w:h = 10:1:1.

Directional couplers vary in design but depend on the controlled power ratio of the coupling and directional properties.

 
Status
Not open for further replies.