PCB layout is one of the basic skills of the PCB designers. It will affect the performance of the whole system, and most of the high-speed designing theory should eventually be verified through PCB layout. In a word, PCB layout is critical for high-speed PCB designing. Generally, PCB layout is divided into right-angled layout, differential layout and S-shaped layout.
As usual, right-angled PCB layout should be avoided in the PCB designing. Right-angled layout is not so bad for the PCB routing .In the sub-GHz applications, capacitors, reflection and EMI cannot be found out by TDR test. The high-speed PCB design engineers should focus pay more attention to the placement, power ground design, vias and so on. Although the problem of right-angled layout is not so serious, it does not mean that we apply right-angled layout freely. Every engineer should be detail-oriented.
The differential signal is used widely in high-speed circuit designing and most of the critical signal in the circuit is designed by differential layout. Compared to the differential signal and single-ended signal traces, there are a lot of advantages with differential PCB layout, such as strong anti-interference, effective suppression to EMI, and accurate timing positioning. The popular low voltage differential signaling is one of the examples of the differential signal technology with small amplitude. The most important rule of the differential layout in the PCB design is to match the line length. The others can be adjusted according to the design requirements and practical application.