AN IMPROVED ADAPTER FOR A LOW INTERMODULATION BOARD-TO-BOARD RF COAXIAL CONNECTION ASSEMBLY

Abstract

The present application relates to a coaxial connector, intended to transmit radio frequency RF signals, of longitudinal axis X, including: - an outer contact forming a body/casing, which at least one of its ends is slotted defining contact petals, a central contact and, - at least one electrical insulating solid structure coaxially interposed between the central contact and the outer contact, which is mechanically retained in the outer contact and in which the central contact is mechanically retained, at least one of the free end of the electrical insulating solid structure having an elasticity of its periphery, at the level of the petals of the outer contact, which is increased compared to the rest of the electrical insulating solid structure.

Claims

1. A coaxial connector,intended to transmit radio frequency RF signals, of longitudinal axis X, comprising: an outer contact forming a body/casing, which at least one of its ends is slotted defining contact petals, a central contact and, at least one electrical insulating solid structure coaxially interposed between the central contact and the outer contact, which is mechanically retained in the outer contact and in which the central contact is mechanically retained, at least one of the free end of said electrical insulating solid structure having an elasticity of its periphery, at the level of the petals of the outer contact, which is increased compared to the rest of said electrical insulating solid structure.

2. A coaxial connector according to claim 1, wherein the increased elasticity ensures a uniformly distributed deformation of the petals of the outer contact or acts as a damper, when the connector is under working conditions.

3. A coaxial connector according to claim 1, wherein the increased elasticity is achieved by at least one axially opening groove formed on at least part the periphery of said electrical insulating solid structure.

4. A coaxial connector according claim 3, wherein the axially opening groove is an annular groove.

5. A coaxial connector according to claim 1, wherein the increased elasticity is achieved by at least one compressible gasket accommodated in a radially opening groove formed on the periphery of said electrical insulating solid structure.

6. A coaxial connector (4) according to claim 1, wherein the increased elasticity is achieved by a plurality holes distributed on at least part the periphery of said electrical insulating solid structure.

7. A coaxial connector) according to claim 1, wherein at least one end of the central contact is slotted defining contact petals each shaped at its front end with a bump, the inner diameter defined by the bumps being the smallest inner diameter of the central contact.

8. A coaxial connector according to claim 1, wherein at least one end of the central contact is slotted defining contact petals each shaped at its front end with a bump, the outer diameter defined by the bumps being the biggest outer diameter of the central contact.

9. A coaxial connector according to claim 1 wherein the outer contact and the electrical insulating solid structure are configured such that in a connection state with a complementary connector, the outer diameter of said electrical insulating solid structure is substantially the same as the inner diameter of said outer contact.

10. A coaxial connector according to claim 1, wherein the central contact and the electrical insulating solid structure are configured such that in a connection state with a complimentary connector, the inner diameter of said electrical insulating solid structure is substantially the same as the outer diameter of said central contact.

11. A coaxial connector according to claim 1, wherein each of the outer contact and the central contact is a symmetric structure, the connector comprising two identical electrical solid insulating structures.

12. A coaxial connection assembly, intended to link two printed circuit boards (PCBs) or a PCB and a module or two modules, comprises: a first receptacle forming a first end socket, intended to be installed in a filter body or cavity or brazed or welded to a first printed circuit board, said first receptacle comprising a pin central contact, a second receptacle forming a second end socket, intended to be installed in a filter body or cavity or brazed or welded to a second printed circuit board, said second receptacle comprising a pin central contact, a coaxial connector, called adapter, according to claim 10, wherein the pin central contact of the first end socket is intended to be inserted into one end of the central contact of the adapter whereas the pin central contact of the second end socket is intended to be inserted into another end of the other central contact of the adapter.

13. A connection assembly according to claim 12, wherein the adapter is intended to be snapped into the first end socket, and to slide relative to the second end socket in order to achieve axial tolerance during the connection.

14. A receptacle forming an end socket, for the connection assembly according to claim 12, comprising an outer contact and a pin central contact and an electrical insulating solid structure which front end has a ring-shaped bump, and/or an gasket made of a shock absorbing material, said gasket being arranged between an annular axially opening groove of the electrical insulating solid structure.

15. An end socket according to claim 14, wherein its pin central contact has a shoulder, said ring-shaped bump axially exceeds said shoulder.

Description

DETAILED DESCRIPTION

[0051] Other advantages and features of the invention will become more apparent on reading the detailed description of exemplary implementations of the invention, given as illustrative and non-limiting examples with reference to the following figures in which:

[0052] FIG. 1 is a longitudinal cross-sectional view of an exemplary RF coaxial connection assembly, intended to link module to printed circuit board comprising two receptacles forming end sockets joined with a coaxial connector forming a connection coupling or adapter according to the invention, in a connection configuration;

[0053] FIG. 1A is a detail view of FIG. 1 showing the coupling between the central contact of the adapter with the pin central contact of one of the end socket;

[0054] FIG. 2 is a longitudinal cross-sectional view of one of the end socket of the exemplary coaxial connection assembly according to FIG. 1;

[0055] FIG. 3 is a longitudinal cross-sectional view of a first embodiment of the adapter according to the invention, such as arranged in the exemplary coaxial connection assembly according to FIG. 1;

[0056] FIG. 4 is a perspective view of the outer contact of the adapter of FIG. 3;

[0057] FIG. 5 is a longitudinal cross-sectional view of the central contact of the adapter of FIG. 3;

[0058] FIGS. 6A to 6C are longitudinal cross-sectional views of the exemplary RF coaxial connection assembly according to FIG. 1, showing different connection configurations with the sliding of the adapter to respectively the maximum, intermediate, and minimum board-to-module distance. FIG. 6A corresponds to a maximum distance between receptacles and a maximum radial misalignment between them. FIG. 6B corresponds to a nominal working condition without any misalignment. FIG. 6C corresponds to a minimum distance between receptacles and a maximum radial misalignment;

[0059] FIG. 7 is a longitudinal cross-sectional view of a second embodiment of the adapter according to the invention;

[0060] FIG. 8 is a longitudinal cross-sectional view of the central contact of the adapter of FIG. 7;

[0061] FIG. 9 is similar to FIG. 1, but with the second embodiment of the adapter according to the invention;

[0062] FIG. 10 is similar to FIGS. 1 or 9, but with another embodiment for the increased elasticity of the solid insulating structure of the adapter and for the bump function of the insulating solid structure of the end socket.

[0063] In clarity purposes, the same references designating the same elements of a connector according to the invention are used for all the FIGS. 1 to 10.

[0064] Hereinafter, the invention is described with reference to any type of RF line.

[0065] FIG. 1 shows a coaxial connection assembly 1 comprising a first receptacle 2 forming an end socket, called snap fitting end socket, a second receptacle 3 forming an end socket, called sliding end socket, and connection coupling or adapter 4, usually called bullet, according to the invention.

[0066] As shown on FIG. 2, the first receptacle 2 is intended to be installed in a filter body or cavity. The first receptacle 2 comprises a rigid body 21 with a recess and a contact pin 22, the recess of the body 21 being arranged at the periphery of the contact pin 22.

[0067] The rigid body 21 forms a ground outer contact.

[0068] An insulator 23 is positioned between the ground outer contact 21 and the contact pin 22.

[0069] The recess of the body 21 houses the contact pin 22 and the insulator 23.

[0070] As shown, the contact pin 22 comprises a shoulder 221.

[0071] The insulator 23 which front end has a ring-shaped bump 231.

[0072] The relative arrangement between the contact pin 22 and the insulator is such that the ring-shaped bump 231 axially exceeds the shoulder 221. The function of the ring-shaped bump 231 is to avoid that the petals of the outer contact 41 of the adapter 4 directly contact the insulator 23 of the receptacle 2, since such a contact would interfere with the deformation of the outer contact 41.

[0073] Besides, an annular inner wall of the outer contact 21 is shaped as an annular bump 211 around the contact pin 22. The annular bump 211 is extended with inclined surfaces 2111 and 2112 inside the body 21. This annular bump ensures that the adapter 4 always stays in the snap side connector, when an user opens the board-to-module to check and repair the system, especially when there are several connections in B2M systems (usually 8, 16, 32, 64 sets).

[0074] The second receptacle 3 is intended to be brazed or welded to a printed circuit board and comprises a rigid body 31 with a recess, a contact pin 32, the recess of the body 31 being arranged at the periphery of the contact pin 32.

[0075] The rigid body 31 forms a ground outer contact.

[0076] An insulator 33 is positioned between the ground outer contact 31 and the contact pin 32.

[0077] The recess of the body 31 houses the contact pin 22 and the insulator 33.

[0078] The body 31 of the second receptacle 3 also presents a centring end piece comprising a centring surface 34. As illustrated in FIG. 1, the centring surface 34 is of annular shape and of circular section.

[0079] The coaxial RF adapter 4 according to the invention is of longitudinal axis X and has a symmetric structure.

[0080] As illustrated in FIG. 3, a first embodiment of a coaxial RF adapter 4 comprises, as axisymmetric components, an outer contact 41 forming a body, a central contact 42, and two identical electrical insulating solid structures 43 interposed between the central contact 42 and the outer contact 41.

[0081] The central contact 42 is mechanically retained by the insulating structures 43 and the shape and the sizing of these components allow them to support any part of the central contact 42, notably to prevent excessive deformation of it.

[0082] The solid insulating structures 43 are mechanically retained into the outer contact 41 and the shape and the sizing of the insulating structures 43 allow them to support any part of the outer contact 41, notably to prevent excessive deformation of it at any direction (radial and circumferential direction).

[0083] The central contact 42 has the functions of RF signal transmission together with the ground contact 41 through the insulating structures (including air), of conformance to dimensional characteristics requested by the equipment and of conformance to mechanical performances and assembling requests. Their general shapes are designed in order to adapt the impedance and transmit the RF signal with a minimum of losses and reflections.

[0084] As shown on FIG. 4, the two ends of the outer contact 41 are slotted forming a plurality of flaps, generally called petals 411, each being delimited between two adjacent axial grooves 412 and acting as a spring towards an outside radial direction to the contact 41. The front end of each petal 411 is shaped with a bump 4111.

[0085] As shown on FIG. 5, the two ends of the central contact 42 are slotted forming a plurality of flaps, generally called petals 421, each being delimited between two adjacent axial grooves 422 and acting as a spring towards an inside radial direction to the contact 42. The front end of each petal 421 is shaped with a bump 4211.

[0086] According to the invention, each of the insulating structure 43 is provided with a front annular groove 431 extending along the axial direction X. The annular groove 431 is opened toward the outside of the adapter 1.

[0087] Now, the connection state will be described.

[0088] When the adapter 4 is connected to the first receptacle 2 and to the second receptacle 3, as illustrated in FIG. 1, the petals 421 of each end of the central contact 42 are open and in forced contact respectively with the contact pins 22, 32.

[0089] The outer diameter of the solid insulating structure 43 is substantially the same as the inner diameter of the petals 411 of the outer contact 41 after radial compression in both first receptacle 2 and second receptacle 3. The surface 432 of the solid insulator structure limits the displacement of the petals 411. The annular groove 431, and the associated increased elasticity in this area ensures that the distributed contact force of each petal 411 on the rigid bodies 21, 31 is uniform.

[0090] During working conditions such as under radial misalignment as shown on FIGS. 6A or 6C, or during vibrations and/or shocks, the outer contact 41 may be more deflected than in the nominal working conditions of FIG. 6B. But the increased elasticity maintains the uniformity of the contact force of each petal 411 in these configurations.

[0091] In other words, during said deflection, the deformation amount of each petal 411 acting as a spring is the same and not over-pressed, thereby ensuring that the contact between the adaptor 4 and the first end socket 2 and second end socket 3 is stable and uniform, eliminating the contact nonlinearity of a board-to-board connection assembly according to the prior art.

[0092] In the same way, the inner diameter of the solid insulating structure 43 is substantially the same as the outer diameter of the petals 421 of the inner contact 42 after radial compression in both first receptacle 2 and second receptacle 3. The surface 434 of the solid insulator structure limits the displacement of the petals 421. The annular groove 431, and the associated increased elasticity in this area ensures that the distributed contact force of each petal 421 on the central contacts 22, 32 is uniform, whatever the conditions of deflection of the petals are.

[0093] In an advantageous embodiment, as shown on FIG. 1A, the petals 421 of the central contact 42 of the adapter 4 are provided with bumps 4211 on their inner diameter. on the side of the first socket 2, the central pin contact 22 is in forced contact with the bumps 4211. As explained below, the inner diameter of the central contact 42 defined by the bumps 4211 is the smallest diameter of said contact 42 such that the central pin contact 22 of the socket 2 can be freely deflected inside. The annular groove 431 of the insulator 43 allows a uniform deformation of petals 421 which allows an intermodulation stability, especially during working conditions, under radial misalignment and/or with vibrations for example. The connection state and effect are also the same on the connecting area of central contact 42 with the pin contact 32 on the second socket 3.

[0094] Hence, the intermodulation stability of the connection assembly 1 is improved.

[0095] The groove 431 does not need to be continuous on the whole periphery of the solid insulating structure 43. Interrupted holes provided along the periphery can also increase the elasticity of the solid insulating structure 43.

[0096] In an advantageous embodiment, one of the end surfaces of the adapter 4 can be semi-locked fixed in the first receptacle 2, notably by clipping the end of the outer contact 41 into the body 21, whereas the other end can be floating mounted in the second receptacle 3.

[0097] On the slide side, the centring surface 34 guides and ensures the adapter 4 can be inserted into the receptacle 3 under blind mating, the surface 311 of the second socket 3 cooperates with the outer contact 41 of the adapter 4, defining a sliding link between bump 4111 of adapter 4 and surface 311 of receptacle. The bump 4111 of petals 411 is compressed by the surface 2113 and 311, the surface 432 of solid insulating structure 43 limits the displacements the petals to ensure that the bump 4111 has a good contact with the outer contact/body of receptacle 2 and 3 during all working conditions, such as under misalignment and/or vibrations and/or shock.

[0098] Moreover, on the snap side, during insertion or extraction of the adapter 4 in the receptacle 2, the bumps 4111 of the petals 411 of the outer contact 41 are compressed against the annular bump 211. The increased elasticity of the insulator 43 due to the annular groove 431 avoids any damage or breakage of the petals 411 against the annular bump 211.

[0099] Hence, according to the invention, the annular groove 431 of each solid insulating structure 43 of the adapter 4 provides a certain degree of elasticity. This elasticity allows insertion and extraction of the adapter 4 in the receptacle 2 without damage and plays a buffering role during misalignment and/or vibration and shock, thereby improving the intermodulation stability of the connection assembly 1, under dynamic working conditions/environment.

[0100] In an advantageous embodiment, as shown on FIG. 2, the bump 231 of the insulator 23 of the first end socket 2 will bear against the solid insulating structure 43 of the adapter 4.

[0101] In case of a strong misalignment during working conditions as shown on FIG. 6C, the bump 231 prevents any contact between the petals 4111 and the insulator 23.

[0102] Therefore, it prevents any modification of the contact pressure of the petals 4111 on the inner surface of the body 21, thereby improving the intermodulation stability of the connection assembly 1, under working conditions.

[0103] On the first end socket side, since the maximum diameter of the bump 231 of the insulator 23 of the first end socket 2 is smaller than the inner diameter of the petals 411 of the outer contact 41 of the adapter 4 under compression, this latter contact 41 will not be subjected to the frictional force of the insulator 23 during the deflection which may occur under working conditions. This also allows to ensure a uniform deformation of the petals 411 of the outer contact 41.

[0104] On the second end socket side, when the minimum plate spacing and the maximum deflection, there is an axial gap between the adapter 4 and the second end socket 3 which ensures that the petals 411 of the outer contact 41 of the adapter 4 will not be subjected to the frictional force of insulator 33 during deflection. This allows to ensure a uniform deformation of the outer contact 41.

[0105] FIGS. 7 to 9 shows a second embodiment of the adapter 4. In this embodiment, a bump 4212 is provided on the outside diameter of the front end of each petal 421 of the central contact 42. Due to the presence of said bump 4212 when a central pin contact 22 or 32 is inserted inside an end of the central contact 42, the outer diameter of the bump 4212 and the inner diameter of the solid insulating structure 43 is substantially the same, which renders stabile the deformation of the central contact 42.

[0106] FIG. 10 shows alternatives.

[0107] Instead of having an axial opening annular groove 431, one compressible gasket 5 is accommodated in a radially opening groove 433 formed on at the periphery of the electrical insulating solid structure 43 of the adapter. In this configuration the diameter of the electrical insulating solid structure 43 should be reduced, at least at its ends, with the radial opening groove 433, in order to free space for the gasket 5.

[0108] Also, the ring-shaped bump 231 can be replaced by a gasket 6 made of a shock absorbing material, which is arranged between an annular axially opening groove 232 of the electrical insulating solid structure 23 and the outer contact 21 of the receptacle.

[0109] Other variants and enhancements can be provided without in any way departing from the framework of the invention.

[0110] If all the shown examples are more specifically about an insulating solid structure with an annular groove, several discontinuous grooves arranged uniformly in a radial direction can be foreseen.

[0111] The expression “comprising a” should be understood to be synonymous with “comprising at least one”, unless otherwise specified.