Plug connector and plug connector assembly

A plug connector for transmitting high-frequency signals, the plug connector comprising:

• a cable having at least one free end;
• a contact mounted on the at least one free end of the cable, the contact having a free contact end on a side facing away from the cable;
• and
• a connecting element, which is disposed between the contact and the cable, and which, in an assembled state, is fixedly connected to the contact and to the cable, the connecting element having at least a first portion with a first outer diameter on a side facing the contact and a second portion with a second outer diameter on a side facing the cable, the second outer diameter being larger than the first outer diameter, a transition section being disposed between the first portion and the second portion, the outer diameter of the connecting element increasing along the transition section, proceeding from the side facing the contact, from the first outer diameter to the second outer diameter, the first portion including at least a third portion that has, at least in some regions of the third portion, an outer diameter corresponding to the second outer diameter.