Electrical connector with improved high frequency signal transmission environment

An electrical connector comprising:

• an insulative housing defining a mating port with upper and lower horizontally extending mating tongues therein;
• a plurality of lower contacts disposed in the housing, each of said lower contacts defining a lower contacting section horizontally exposed upon the lower mating tongue and a lower mounting section downwardly extending behind the lower mating tongue;
• and
• a plurality of upper contacts disposed in the housing, each of said upper contacts defining an upper contacting section horizontally exposed upon the upper mating tongue and an upper mounting section downwardly extending behind the upper mating tongue and behind the mounting sections of the lower contacts;
• wherein
• the upper contacts includes one grounding contact and two differential pairs by two sides of the grounding contact, and the lower contacts includes two contacts under condition that the upper mounting sections of said two differential pairs are deflected transversely away from each other so as to enlarge a pitch with regard to the grounding contact in comparison with that among the upper contacting sections of said upper contacts wherein in a front-to-back direction, the lower mounting sections of the two lower contacts respectively located between the grounding contact and the corresponding differential pair.