Electrical connector having terminal portions in specific arrangement and a grounding plate for excellent high-frequency characteristics

1. A first connector comprising:

a first insulative housing defining a base member and a mating member extending forwardly from the base member in a mating direction, the mating member defining opposite first and second mating faces in a vertical direction perpendicular to said mating direction;

a set of first upper contacts retained in the first housing and including an upper differential pairs and two upper grounding contacts located at two opposite sides of the upper differential pairs to be arranged upon the first mating face in a longitudinal direction;

a set of first lower contacts retained in the first housing and including a first lower differential pairs, a second lower differential pairs and a lower grounding contact; and

a first grounding plate retained in the first housing and disposed between the set of first upper contacts and the set of first lower contacts;

wherein the first lower differential pairs each defines a first terminal portion and a first contacting section, the second lower differential pairs each defines a second terminal portion and a second contacting section, and the lower grounding contact defines a tail section and a first grounding arm, the first contacting sections, the second contacting sections and the first grounding arm are arranged upon the second mating face in the longitudinal direction under a condition that the two first contacting sections and the two second contacting sections are respectively disposed at two opposite sides of the first grounding arm, and the first terminal portions are arranged in a first row, and the second terminal portions and the tail section are arranged in a second row.

2. The first connector as described in claim 1 , wherein the lower grounding contact defines a second grounding arm parallel to the first grounding arm, and the two first contacting sections are disposed between the first and second grounding arms.

3. The first connector as described in claim 2 , wherein the set of first upper contacts each defines a leg section disposed in a same plane and arranged in a third row located behind the first and second rows.

4. The first connector as described in claim 2 , wherein the upper differential pairs each defines an upper contacting section, and the first grounding plate defines a first shielding arm disposed between the two upper grounding contacts in the longitudinal direction and between the upper contacting sections and the first contacting sections in the vertical direction.

5. The first connector as described in claim 4 , wherein the first housing defines an upper member providing the opposite first and second mating faces and a lower member engaging with the upper member, and the set of first upper contacts is retained in the upper member, the set of first lower contacts is retained in the lower member.

6. The first connector as described in claim 5 , wherein the upper member defines a receiving room at a rear portion thereof, and the lower member is retained in the receiving room.

7. The electrical connector as described in claim 6 , wherein the lower member defines a plurality of retaining slots recessed from a rear face thereof, and the set of first upper contacts define restricting portions retained in the corresponding retaining slots.

8. An electrical connector assembly comprising:

a first connector including:

a first insulative housing defining opposite first and second mating faces in a vertical direction;

a set of first upper contacts retained in the first housing arranged upon the first mating face in a longitudinal direction;

a set of first lower contacts including a first lower differential pairs having two first contacting sections, a second lower differential pairs having two second contacting sections and a grounding contact having two opposite grounding arms, and the first contacting sections, the second contacting sections and the two grounding arms arranged upon the second mating face in a longitudinal direction under a condition that the two first contacting sections are disposed between the two grounding arms, the two first contacting sections and the two second contacting sections are respectively disposed at two opposite sides of one of the grounding arms;

a second connector mated with the first connector and including:

a second insulative housing having a mating room;

a set of second upper contacts and a set of second lower contacts oppositely disposed at two sides of the mating portion, the set of second upper contacts each defining a first flexible contacting arm downwardly projecting into the mating room, and the set of second lower contacts each defining a second flexible contacting arm upwardly projecting into the mating room; and

a second grounding plate retained in the second housing and disposed between the set of second upper contacts and the set of second lower contacts.

9. The electrical connector assembly as described in claim 8 , wherein the first lower differential pairs each defines a first terminal portion connecting with the first contacting section, the second lower differential pairs each defines a second terminal portion connecting with the second contacting section, and the grounding contact defines a tail section connecting with the two grounding arms, and the first terminal portions are arranged in a first row, and the second terminal portions and the tail section are arranged in a second row.

10. The electrical connector assembly as described in claim 8 , wherein the first connector further defines a first grounding plate retained in the first housing and disposed between the set of first upper contacts and the set of first lower contacts.

11. The electrical connector as described in claim 10 , wherein the set of first upper contacts include an upper differential pairs and two upper grounding contacts located at two opposite sides of the upper differential pairs, the upper differential pairs each defines an upper contacting section, and the first grounding plate defines a first shielding arm disposed between the two grounding contacts in the longitudinal direction and between the upper contacting sections and the first contacting sections in the vertical direction.

12. The electrical connector assembly as described in claim 8 , wherein the second housing defines a second base portion, first and second tongue portions oppositely extending forward from the second base portion, and the mating room is disposed between the first and second tongue portions.

13. The electrical connector assembly as described in claim 12 , wherein each second upper contact defines a first fixing portion retained in the first tongue portion, each second lower contacts defines a second fixing portion retained in the second tongue portion, the second grounding plate is retained in the second base portion and disposed between the first fixing portions and the second fixing portions.

14. The electrical connector assembly as described in claim 12 , wherein the second grounding plate defines a second base plate and five second shielding arms extending forward from a front end of the second base plate.

15. An electrical connector assembly comprising:

a printed circuit board;

a first connector mounted upon the printed circuit board, said connector including:

a first insulative housing defining an opening in a front-to-back direction;

a mating tongue assembled to the housing and extending through the opening and defining opposite first and second surfaces thereon;

a plurality of first contacts defining first contacting sections exposed upon the first surface and first mounting sections mounted to the printed circuit board;

a plurality of second contacts defining second contacting sections exposed upon the second surface and second mounting sections mounted to the printed circuit board;

a grounding plate located between the first contacting sections and second contacting sections and defining grounding mounting sections mounted to the printed circuit board; wherein

the mating tongue is configured to have the first contacts assembled thereto in a direction parallel to said front-to-back direction while having the second contacts assembled thereto in a vertical direction perpendicular to said front-to-back direction.

16. The electrical connector assembly as claimed in claim 15 , wherein the second contacts are designated with differential pairs and grounding contacts under condition that the second mounting sections of the grounding contacts share a same piece which is located behind those of the corresponding differential pairs sandwiched therebetween.

17. The electrical connector assembly as claimed in claim 16 , wherein the first mounting sections are configured for surface mounting while the second mounting sections are configured for through hole mounting.

18. The electrical connector assembly as claimed in claim 16 , wherein the second mounting sections of the grounding contacts share the same piece further located transversely aligned with those of other corresponding differential pairs sandwiched therebetween.

19. The electrical connector assembly as claimed in claim 16 , further including a spacer integrally formed with the second contacts.

20. The electrical connector assembly as claimed in claim 19 , wherein said spacer cooperates with the mating tongue to sandwich the grounding plate therebewteen.