In order to make the invention better understood, there follows a description by way of non-limiting example of an embodiment given with reference to the accompanying drawings, in which:
The connector element 2 can slide in limited manner inside the connector element 1.
The connector element 1 shown is secured on a printed circuit card 3, another printed circuit card 4 being shown approaching towards the connector, as represented by arrows.
Below, the connector element 1 and its components are said to be “stationary” while the connector element 2 and its components are said to be “movable”.
The stationary connector element 1 comprises a ground outer contact body 5 having an annular base portion 6 connected to an annular bearing surface 7 disposed concentrically with the body 5 and projecting towards the inside thereof.
The stationary outer contact made in this way is secured to the printed circuit card 3 by solder 8.
The stationary central contact includes a cylindrical contact body 9 presenting a step from which there extends an annular bearing surface 10, which thus overhangs the outside of the body 9. Insulation 11 is interposed between the stationary contact body 9 and the bearing surface 7 of the stationary outer contact.
The movable connector element 2 comprises a tubular outer body 12 extended by an annular bearing surface 13 that lies in contact with the bearing surface 7 of the stationary outer contact, as can be seen in the drawing. The bearing surface 13 is offset inwards relative to the body 12.
The movable central contact has a movable contact body 14 extended by an annular bearing surface 15 that is offset outwards. As can be seen in
The stationary contact body 9 is secured to the printed circuit card 3 by solder, in particular in a plated-through hole in the printed circuit card. Insulation 16 is interposed between the body of the movable outer contact 12 and the body of the movable central contact 14. As can be seen in
A helical compression spring 17 is put into place between the stationary and movable outer contacts, and a helical compression spring 18 is put into place between the stationary and movable central contacts, the helical springs 17 and 18, when compressed by the card 4 pressing thereagainst, tending to apply the movable central and outer contacts under pressure against the printed circuit card 4.
A shielding ring 19 for shielding against electromagnetic radiation is placed around the bearing surface 13.
When the card 4 presses against the movable connector element, the element slides in the stationary connector element and a compression force due to the springs presses the stationary and movable central contacts between determined wheels of the card, with it being possible for them to be off-center by up to 0.7 millimeters (mm).
In the example shown in the position of
It can be seen that the displacement between the minimum and maximum positions is large, with a minimum operating stroke of 1.2 mm being obtained. In the example shown, this stroke is 1.6 mm. This stroke can be further increased by modifying the length dimensions of the movable outer contact and of the movable central contact. In practice, it is possible to envisage a distance between cards of up to 20 mm.
In the invention, a reflection coefficient at 18 GHz is obtained that is small and independent of the distance between the printed circuits, by defining the inside diameters (D) of the ground bodies 7 and 12 and the outside diameters (d) of the central contacts 9 and 14 that govern the impedance of the transmission line segments marked by arrows A, B, and C in
so that they are equal and identical to the characteristic impedance Z0 of the access lines, e.g. 50 ohms (Ω). The segments A and C are of unchanging lengths. The matching zones D and E are dimensional transitions between the zones A, B, and C of characteristic impedance Z0 and they are likewise of unvarying lengths. Their greatest impedances and their widths are defined so as to minimize reflections throughout the working frequency band 0-18 GHz. A change in the distance between the printed circuits 3 and 4 therefore does not change the characteristics of these matching zones, with length varying solely in the segment B and this has no impact on reflection levels since it presents the characteristic impedance Z0.
This ensures very good radio frequency characteristics up to 18 GHz independently of the distance between the cards. In particular, a standing wave ratio (SWR) of less than 1.5 is obtained up to a frequency of 18 GHz.
Although the invention is described above with reference to a particular embodiment of the invention, it is clear that the invention is not limited in any way thereto and variations and modifications can be applied thereto without going beyond its ambit as defined in the following claims.
Although the present invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.
Number | Date | Country | Kind |
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06 53539 | Aug 2006 | FR | national |