The signal transmission can be divided into two categories: simulation signal transmission and digital signal transmission. Simulation or digital signal connector required function should be able to protect the integrity of the transmitted voltage pulse signal, the integrity of the pulse signal waveform and its amplitude. Different data signal pulse frequency and the simulated signal, the pulse transfer speed determines the maximum frequency of the pulse are protected, the data pulse transmission speed is much faster than typical simulated signal, and some pulse connector transfer speed is close to one hundred billion per second range, in today's microelectronics technology, usually the connector as a wire look at growing so fast frequency-dependent wavelength comparable to the connector size.
   
When the air plug or each other contact system such as a cable assembly is used in high-speed data signal transmission, the corresponding description of the connector performance is changed. Instead of the characteristic impedance of the resistor and mutual contact of the crosstalk in the system becomes particularly important. To control the characteristic impedance of the connector to become a major ideological trends in the cable is on the crosstalk control. The characteristic impedance of the connector reason why such an important position, because the resistor geometry difficult to achieve the complete reunification, coupled with the connector size is very small, to minimize the possibility of crosstalk. In the cable, the control of the geometry is easier to achieve its characteristic impedance is also easy to control the length of the cable may cause potential crosstalk.