Abstract:Signal integrity is important in highfrequency and highspeed circuits. The discontinuity of differential vias seriously affects signal integrity. According to the design requirements for lowreflection, hightransmission and impedancestabilization of differential vias for differential and commonmode signals in highspeed printed circuit boards (PCB), firstly, the equivalent physical model and the circuit model of the differential vias are established to analyze the differential signal and the common mode signal of the differential vias. Then, based on the PCB stack structure and wiring pattern design, threedimensional electromagnetic simulation software HFSS is used to set different vias center distance, antipad diameter and ground vias number. Time domain impedance, return loss, and insertion loss of differential vias are simulated and analyzed. Besides, Sparameters and impedance changes in the time domain are used to analyze the differential performance and commonmode performance of vias. Finally, through the simulation results, it is found that the center of the vias hole is 38 mils(1 mil=0025 4 mm), the antipad diameter is 32 mils, and the set of double vias and ground vias optimizes the performance of differential signals and common mode signals. This paper presents a new idea for optimizing the performance of differential vias and provides a reference for highspeed differential vias design.