To reiterate the issues one usually faces when designing high speed circuit boards (from the video above):
- Timing: the lengths of the tracks must be similar enough for the electrical signals to arrive at the receiver at the same time. ~0.6 times the speed of light is too slow!
- Signal Integrity: The shape of the signal needs to be right when it arrives at the receiver.
- Noise: There can be a lot of crosstalk and noise on a high speed PCB and this noise can adversely affect signals.
To 'solve' these concerns:
- Maintain the correct impedance from the transmitter to the receiver. This is not always trivial and so this is usually the biggest problem!
- Matched lengths minimise signal skew.
- Leave space around the traces to minimise noise. More space makes an exponential difference.