Due to sensor development and the E/E architecture presented, the data volumes to be transmitted are increasingly shifting toward high-speed transmission, which depends primarily on controlling the connector’s impedance. If this impedance fluctuates, resonances occur, which in turn result in signal transmission losses. Due to its geometry, a connector always poses a potential risk of impedance fluctuations, which are caused, among other things, by changes in material or geometry. This is

because impedance is determined by inductive and capacitive properties, which depend on the size, arrangement, and design of the pins. Changes in cross-sectional area, in particular, have a negative effect, which is why they must be minimized as much as possible. Furthermore, dielectrics (substances that are electrically weakly conductive or non-conductive) near the signal path can also have negative effects, which is why selecting the correct insulating material is equally important. In addition, there are also effects caused by coupling losses—the losses at the contact point between the blade and the spring. Finally, impedance fluctuations can be caused by protruding conductive elements that act as antennas. All these effects are summarized as insertion loss (the ratio of the outgoing signal to the incoming signal). In addition, there is return loss (return loss), which describes the ratio of the reflected signal to the signal to be transmitted.In light of the ongoing miniaturization of assemblies, EMC protection plays a particularly important role: This is because the high-frequency signals generated in this process are especially susceptible to interference from unwanted electromagnetic effects. Even the slightest interference is enough to cause significant distortion in data transmission, incorrect measurement signals from sensors, and inappropriate control commands—a scenario that is absolutely unacceptable from a safety perspective.
A shielded connector helps, because within an assembly, a connector always acts both as a sink for interference and as a source of interference. The component can also be disrupted by other components and, in turn, exerts an electromagnetic effect on surrounding components. shielding reduces both of these effects by a factor of approximately 100 to 200. 

On the topic of robustness: Shock and vibration jeopardize the stability of data transmission just as much as chemical and thermal environmental influences caused by extreme temperatures, significant temperature fluctuations, corrosive gases, moisture, and dirt. The contact surface (contact surface) significantly determines the service life of the connector, because during operation, micro-movements occur between the two parts of the connector; over time, these lead to surface abrasion and thus to increased contact resistance (contact resistance), resulting in less effective signal transmission. A high-quality and durable contact coating (contact plating) helps minimize this surface abrasion.
In the contact system, a double-sided spring-loaded connector (Female) performs well, as it guarantees a contact point at all times, regardless of external influences. A “hermaphroditic” contact system offers even greater robustness, as the contacts interlock when plugged in, ensuring maximum contact reliability.

With limited installation space in automobiles, there is little room for sensors and ECUs, which in turn means that connectors must reduce their dimensions even further while maintaining the same or even higher performance. This is ideal for surface-mount technology (SMT), as—unlike press-fit technology—it enables a significantly smaller pitch as well as double-sided assembly of the printed circuit board. 

The trend toward installing more and smaller connectors in assemblies results in longer tolerance chains, meaning connectors must compensate for increasingly larger tolerances during both assembly and operation. Connectors are already available that can absorb shocks and vibrations even more effectivelyconnector.