1. Signal Flow Graphs Examples
TE Sec: BS
S. M. Umar Talha
Special Thanks to: Dr. S. Saad Azhar Ali

2. Example

3. Forward paths P1

4. Forward paths P2

5. Forward paths P3

6. Loops

7. Loops

8. 2 Non Touching loops

9. Other 2 Non touching Loops
L2L4=(A43A34) (A65A56)
L2L5=(A43A34) (A76A67)
L2L6=(A43A34) (A77)
L2L8=(A43A34) (A65A76A57)
L3L5=(A54A45) (A76A67)
L3L8=(A54A45) (A65A76A57)
L4L7= (A65A56) (A42A34A32)
L4L6= (A65A56) (A77)
L5L7= (A76A67) (A42A34A32)

10. 3 Non Touching Loops

11. 3 Non Touching Loops

12. ∆
∆=1-ΣiLi +
(L1L3+ L1L4+L1L5+L1L6+L1L8+L2L4+ L2L5+L2L6+L2L8+L3L5+L3L8+ L4L7+ L4L6+ L5L7) –
(L1L3L5 + L1L4L6 + L2L4L6 + L4L6L7)

13. ∆i
∆1 = ∆3 = 1
∆2 = 1- (L1+L3+L5) + (L2L4)