I. Introduction
Differential signaling has been widely used in high-speed I/O interconnect standards like PCI-Express and Serial ATA. It has several advantages, such as a high transmission rate due to low signal swing, little electromagnetic interference (EMI), and common-mode noise immunity. Considerable signal integrity issues, however, still limit the link performance and become bottlenecks during system integration. Such issues include resistive losses, reflections, inductive ringing and crosstalk between differential pairs [2], [3].