Losses and Crosstalk

1. What is Fiber weave effect? how to control fiber weave affect? Hint: route at 10 degree angle
2.  What is typical PCB core materials used in industry? FR-4, Megtron-6, N4000, FR408HR
3.  What is typical Dissipation factor range for PCB material? 0.02 to 0.002
4.  DDR3 routing guidelines, Is mandatory to maintain length matching between DQS and CLK?
5. Who generates DQS? while writing Controller, While reading DRAM chip
6. What is write levelling?
7. How to reduce cross talk?
8. PCIe protocol electrical validation steps?
9. What is typical value for losses in dB? -0.1dB/inch/GHz...It means for a lossless line, 30 inch line,at 1GHz there will -3dB losses expected.
10. How to Reduce NEXT, FEXT : Ans:  Moving traces farther apart and Bringing return plane closer
11. What is FEXT in Stripline: Zero
12. What is Nyquist/fundamental frequency at 5Gbps? 2.5GHz sinusoidal: Hint: without this frequency we can achieve 5Gbps pulse train?
13. CTLE equalization will open eye when S21-25dB
14.  How to keep insersion loss at minimum;
      Minimize conductor loss
      Minimize dielectric loss
      Keep Microstrip traces short
15 Skin depth relation with freqency? Invesely proportional
16. In a low loss channel, how far can you go at 10 Gbps using best equalization?
-25 dB(this is max S21 can be recovered with CTLE) = -0.1 dB/inch/GHz x Len x 5 GHz= 0.5 dB/inch x Len
 Length = 50 inches
17. What is aspect ratio of PCB?