UNITED RF COAXIAL CONNECTOR FOR A MODULAR OR THREE-MODULE PCB OR CARD WITH ADJUSTING DIAMETER CONNECTORS, WHICH HAS AT LEAST A SLIDE ADJUSTMENT IN THE LENGTH OF THE LENGTH OF THE CONNECTION

Description

technical field

[0001] The present invention relates to the field of electrical connection and more particularly to a single RF connector.

[0002] Such a unit connector can notably be used to connect two parallel printed circuits, usually called board-to-board (B2B) connection or printed circuit board (PCB), to another component such as a module or a filter, generally called a filter board or module board.

[0003] The applications particularly targeted by the invention are the connection of telecommunications equipment such as BTS base transceiver stations, RRU / RRH units (Remote Radio Unit / Remote Radio Head), the antenna-integrated RRU / RRH solution, Telecom Massive MIMO antenna applications and distributed antenna systems for the wireless communications market.

[0004] The invention also relates generally to connectors in the fields of telecommunications, medicine, industry, aeronautics, transport and space.

[0005] The connectors according to the invention can in particular be used to connect two parallel printed circuits, usually called a board-to-board connection system or printed circuit board to another component such as a module, a filter or a power amplifier or an antenna, or module to module.

[0006] By "RF connector" we mean a connector capable of transmitting signals from the Direct Current (DC) range to the radio frequency (RF) range, including the microwave (HF) range, the signals being high-speed digital signals (HSDL for High Speed ​​Data Link) or radio frequency (RF) signals.

[0007] By "unitary", we mean that the connector according to the invention, once assembled, forms a single object. Previous technique

[0008] With the continued development of wireless communication technology, board-to-board connectors are increasingly used to interconnect modules in wireless systems, such as communication base stations, wireless access networks (HARs), repeaters, GPS devices, and other similar applications. The three main trends in wireless devices are reduced size, lower cost, and easier installation, as well as the increasing frequency of the RF signals used. For board-to-board connections, the market also demands smaller, less expensive, and more modular designs.

[0009] Examples of dedicated connection assemblies for cellular radiotelephony interconnects already exist on the market and in the prior art. Indeed, the trend in this market is to minimize RF (radio frequency) losses in order to reduce the number of amplifier components in base stations. To achieve this, on the one hand, the radio section of the stations is increasingly being relocated closer to the transmit / receive antennas, within RRU / RRH transmitter modules, and on the other hand, the RF cables internal to the radio units are being replaced by direct interconnects.

[0010] Card-to-card connections have thus developed with each successive generation over the last decade.

[0011] Commercial products already exist to make these connections, including single-unit products.

[0012] One example is the IMP series connectors, registered in the applicant's name and described in patent EP1028490B1. These connectors are not suitable for all configurations, primarily due to their limited axial travel and tight radial positioning tolerance. Furthermore, the frequencies for which these connectors are designed are not high.

[0013] We can also mention the coaxial compression connectors marketed by TYCO ELECTRONICS under commercial reference 619127-1. These connectors are bulky due to their large diameter for board-to-board applications. They also have a short axial travel and a limited operating frequency range.

[0014] Furthermore, US patent 6776668B1 discloses a coaxial connector for a board-to-board connection, suitable for compensating for an angular misalignment between printed boards of up to 3°. However, the connector is not suitable for providing a wide range of axial distance between the two boards. US patent documents US2023 / 085352A1 and US11936145B2 also disclose coaxial connectors.

[0015] More generally, there is a need to further improve board-to-board, board-to-module, or board-to-filter connections, particularly to meet the specifications set by the inventors, namely: a connector with a very simple structure, which consists of a minimum of spare parts, and which minimizes environmental impact by not using hazardous substances such as per and polyfluoroalkyl substances (PFAS), lead or beryllium; a simple structure and a low-cost connector; the possibility of using a connector reference for a wide axial positioning range between two parallel printed boards, typically + / - 1 mm or + / - 1.5 mm; the possibility of connecting two parallel printed boards, radially offset from each other, typically with a radial misalignment of + / - 0.5 mm to + / - 1 mm; a footprint, therefore an outside diameter, typically less than 5 mm; an operating frequency range from DC to 20 GHz.

[0016] The invention aims to meet all or part of this need. Description of the invention

[0017] To this end, the invention relates, according to one of its aspects, to a single coaxial connector, intended for transmitting radio frequency (RF) signals, with a longitudinal axis X, comprising: three coaxial lines adjacent along the longitudinal axis X and whose diameter is increasing from one line to the next adjacent line, from one of the longitudinal ends of the connector to the other of its longitudinal ends, each of the lines comprising each of a central contact and an outer contact arranged around the central contact, at least one central contact of a coaxial line being sliding in a central contact of one of the other lines adjacent to it, at least one outer contact of a coaxial line being sliding in an outer contact of one of the other lines adjacent to it so that the length of the intermediate coaxial line can vary, the volume between the central contact and the outer contact of the intermediate line being devoid of solid electrical insulation; a guiding element, preferably in the form of a hollow tube, whose internal surface is adapted to mechanically guide at least the external contact of the coaxial line extending from one of the longitudinal ends of the connector.

[0018] By "devoid of solid electrical insulation", we mean that the electrical insulation consists of air or an electrically non-conductive gas, for example nitrogen, or a vacuum.

[0019] By "solidarity", we mean fixed or made entirely with.

[0020] By "intermediate coaxial line" we mean the coaxial line arranged between the two end coaxial lines.

[0021] Preferably, the guide element is adapted to guide the outer contact of the largest diameter.

[0022] According to another advantageous embodiment, the guide element is integral with the outer contact of the coaxial line which extends from the other of the longitudinal ends of the connector, opposite to that from which extends the outer contact mechanically guided by the guide tube.

[0023] Preferably, the guide element is integral with the smaller diameter outer contact.

[0024] According to another advantageous embodiment, the guide element is overmolded around the outer contact of the coaxial line.

[0025] In this design, the guiding element is further insulated by forming an electrically insulating block. This electrically insulating block allows for the housing and mechanical retention of the central contact, at least for the first coaxial line.

[0026] Advantageously, the guide element is also adapted to mechanically retain the external contact of the coaxial line, preferably to form an axial stop for the latter.

[0027] The center contacts of coaxial lines consist of a first electrically conductive body having at least two different diameters, forming respectively the center contact of the first coaxial line and the center contact of the second coaxial line, and a second electrically conductive body, forming the center contact of a third coaxial line, sliding on the center contact of the second coaxial line, which has a larger diameter than that of the first coaxial line. The first electrically conductive body extends from one longitudinal end of the connector and the second electrically conductive body extends from the other longitudinal end. Advantageously, such a configuration of the coaxial line center contacts ensures stable electrical contact with low resistance between the coaxial lines.

[0028] Preferably, the second electrically conductive body comprises an open end including petals in mechanical and electrical contact with the outer surface of the first electrically conductive body.

[0029] According to an advantageous embodiment, a single coaxial line slides into another coaxial line, the third coaxial line being of larger diameter, the outer contact of the third coaxial line being integral with the outer contact of the second line with a diameter reduction.

[0030] According to an advantageous embodiment, the unit coaxial connector comprises: a third electrically conductive body, forming the outer contact of a first coaxial line, integral with the guide element, preferably by being overmolded with the latter; a fourth electrically conductive body having two different diameters, forming respectively the outer contact of a second coaxial line and the outer contact of a third coaxial line, the outer contact of the second coaxial line being sliding on the outer contact of the first coaxial line, the outer contact of the third coaxial line, of larger diameter than that of the second coaxial line, being mechanically guided by the guide element.

[0031] According to another advantageous embodiment, the connector includes at least one elastic return means for bringing the fourth electrically conductive body back into its fully extended position relative to the third electrically conductive body. This elastic return means ensures the movement of the sliding outer contact and the contact force with a PCB to which the connector is intended to be electrically connected.

[0032] According to this other method, the elastic return means consists of a helical spring wound around between the guide tube and the outer contact of the smallest diameter of the fourth electrically conductive body and in axial abutment on one side against a shoulder of the guide element and on the other side against the shoulder forming the junction between the outer contact of the smallest diameter and that of the largest diameter of the fourth body.

[0033] According to another advantageous embodiment, the connector includes at least one elastic return means for bringing the second electrically conductive body back into its fully extended position relative to the first electrically conductive body. This elastic return means ensures the movement of the sliding central contact and the contact force with a PCB to which the connector is intended to be electrically connected.

[0034] According to this other method, the elastic return means consists of a helical spring housed in a bore of the larger diameter central contact of the first electrically conductive body and axially abutted against the blind end of a tube forming the central contact of the second electrically conductive body.

[0035] According to an advantageous embodiment: The guide element is electrically conductive and integral with the external contact formed by the third electrically conductive body; the first electrically conductive body is a cylindrical sleeve forming the central contacts of the first and second coaxial lines and a contact point mounted axially movable in the sleeve with an axial stop; the second electrically conductive body forming the central contact of the third coaxial line is mounted to slide relative to the fourth electrically conductive body forming the external contact of the second coaxial line and the external contact of the third coaxial line. so that the force exerted by each of the elastic return means can achieve the electrical connection between, on the one hand, at one of the longitudinal ends of the connector, the contact tip and the guide element and respectively the signal track and the ground track of a first printed circuit board (PCB1) and, on the other hand, at the other of the longitudinal ends of the connector, the center contact and the outer contact of the third coaxial line and respectively the signal track and the ground track of a second printed circuit board (PCB2).

[0036] Thus, according to this method, an electrical connection can be made board-to-board (PCB 1, PCB2), solely by mechanical force of application, and therefore without any soldering / brazing being necessary.

[0037] According to an advantageous insulation alternative, the connector includes an electrically insulating block arranged between the outer contact and the center contact of the third coaxial line along at least part of the axial length of the latter. This electrically insulating block includes at least one through axial hole. This insulating block improves the mechanical retention of the sliding center contact. The axial hole(s) along the length of the sliding coaxial line help maintain a constant impedance. In this alternative, the diameter of the sliding coaxial line is increased.

[0038] According to an advantageous variant, the guide element includes centering and / or mechanical retention feet adapted to position and / or pre-assemble, preferably by press fitting or clipping, the element and thereby the connector to a printed circuit board (PCB1) to which a coaxial line of the connector is intended to be connected by being secured, in particular by brazing.

[0039] The guide element, and where applicable the electrically insulating block, is / are advantageously made of an electrically insulating material selected from aliphatic polyamide (PA), a liquid crystal polymer (PCL), polyetheretherketone (PEEK), or a mixture thereof. This eliminates the need for any use of plastic materials from the PFA family.

[0040] Preferably, the material used to make the contacts is a copper alloy free of lead and beryllium.

[0041] Advantageously, the external contact of one of the coaxial lines at a longitudinal end of the connector includes at least one leg, intended to serve as a permanent electrical and mechanical connection with a printed circuit board (PCB1). This facilitates and strengthens the connection, notably by providing a large soldering surface.

[0042] According to an advantageous design, the outer contact of one of the coaxial lines at a longitudinal end of the connector comprises, at its free end, two concentric flanges, one inside the other forming two steps, with the outer one extending radially outwards. This allows for an increased radial misalignment acceptable to the connector, without affecting the impedance of the sliding coaxial line.

[0043] The invention also relates to a coaxial connection assembly, intended in particular for connecting two printed circuit boards (PCB1, PCB2) or a board to a filter or a board to a module, comprising: at least one single coaxial connector according to the present invention, one of whose coaxial lines at one longitudinal end of the connector is intended to be connected by being secured, in particular by soldering, to a first printed circuit board (PCB1), at least one interconnection plate, one main face of which is intended to be connected by being secured, in particular by soldering, to a second printed circuit board (PCB2) or to a module or a filter, and the other main face of which is intended to be connected to another of the coaxial lines at the other longitudinal end of the connector.

[0044] Preferably, the other coaxial line at the other longitudinal end of the connector, intended to be connected to the other main face of the interconnect plate, is the sliding one.

[0045] The coaxial connection assembly can be multi-way and include: several coaxial connectors arranged parallel to each other; several interconnecting plates each intended to be connected to the other coaxial lines of each connector.

[0046] The invention also relates to a method for manufacturing a single coaxial connector as described above, comprising the following steps: i / supply of a third electrically conductive body forming the outer contact of a first coaxial line; ii / supply of a fourth electrically conductive body having two different diameters, forming respectively the outer contact of a second coaxial line and the outer contact of a third coaxial line, iii / mechanical assembly of a first connector sub-assembly comprising a first electrically conductive body having at least two different diameters, forming respectively the central contact of the first coaxial line and the central contact of the second coaxial line, and a second electrically conductive body forming the central contact of the third coaxial line, sliding on the central contact of the second coaxial line, of a larger diameter than that of the first coaxial line;iv / overmolding of the guide element onto the third electrically conductive body so as to form a second connector subassembly, then mechanically assembling the first subassembly into the second subassembly; or iv / ' overmolding of the guide element both onto the third electrically conductive body and onto the center contact of the first coaxial line of the first connector subassembly so as to form a second connector subassembly; v / mechanically assembling the fourth electrically conductive body into the second subassembly so that the outer contact of the second coaxial line slides on the outer contact of the first coaxial line and the guide element mechanically guides the outer contact of the third coaxial line.

[0047] Preferably, the overmolding step iv is carried out so as to form an electrically insulating block in the form of a hollow tube suitable for housing the center contact of the first coaxial line.

[0048] According to an advantageous variant, the assembly step iii / is carried out with a central contact of the third coaxial line in the form of a blind tube and with a central contact of the second coaxial line provided with a bore, and by housing a helical spring in the bore as an axial stop against the blind end of the tube.

[0049] According to another advantageous variant, the assembly step v / is carried out by first housing a helical spring around the outer contact of the first coaxial line, axially butted on one side against a shoulder of the guide element and on the other side against the shoulder forming the junction between the outer contact of the second coaxial line and that of the third coaxial line.

[0050] Thus, the invention essentially consists of a unit coaxial connector comprising three coaxial lines, mainly devoid of solid electrical insulation, of constant nominal impedances on each coaxial line, regardless of the length of each of said coaxial lines, the nominal impedances being preferably equal and of which at least one slides into another adjacent one, and whose central and outer contact diameters increase from one longitudinal end to the other of the connector, with a peripheral guiding element, preferably in the form of a tube which allows to guide and recenter the sliding outer contact over a large length of travel.

[0051] The characteristic impedance of each coaxial line and of the entire connector remains stable, typically at 50 ohms, along the entire length of the connector, regardless of the final distance between the PCBs connected by the connector. It is also possible to achieve a stable impedance of 75 ohms or any other value along the entire connector length. There is no impedance mismatch along the connector axis when moving from one coaxial line to another: the predominantly air-filled nature of the coaxial lines prevents the impedance variations between solid and air-insulated areas that can occur in state-of-the-art connectors.

[0052] The length adjustment of the connector according to the invention to accommodate the different distances between PCBs to be connected is achieved by varying the length of the sliding coaxial line: The outer or ground contact slides outside the body of the outer or ground contact of smaller diameter, belonging to an end coaxial line, decreasing or increasing the length of the sliding coaxial line; the center contact, belonging to an end coaxial line, slides over the center contact of smaller diameter, decreasing or increasing the length of the sliding coaxial line.

[0053] The invention offers numerous advantages compared to state-of-the-art connectors, including: The ability to achieve large axial misalignments, typically on the order of 2.4 mm variation in the distance between two PCBs to be connected, without any change in the impedance of the coaxial lines as a function of the distance between PCBs, which remains stable, typically at 50 Ω; the absence of solid electrical insulators, leaving air as the insulator, whose lower dielectric constant allows for a reduction in the dimensions (diameters) of the coaxial lines and a compact connector. For example, the largest diameter coaxial line can have an outer contact of 3.5 mm in diameter and a center contact of 1.5 mm; the functional separation between parts with electrical functions, such as the outer contacts, and the outer guide tube with mechanical functions for guiding and retaining the sliding outer contact allows for the use of materials best suited to these functions: the tube can be made of plastic,Preferably overmolded onto the smaller diameter fixed outer contact, the bodies of the outer or ground contacts, due to their simple geometry, do not require the use of copper alloys containing beryllium or lead, which allow for increased elasticity of copper alloys. The small number of connection operations required for the connector necessitates lower mechanical performance of the materials used in the metal parts and therefore also allows the use of copper alloys without beryllium or lead. Electrical parts with a current-carrying function, not providing a structural mechanical function, can be made with very thin walls, resulting in material, weight, and cost savings. The main use is of air lines, where applicable with the most compact solid insulation possible.Avoids the use of PFA plastics. The plastics used for the tube and solid insulator can be PA, LCP, or PEEK. These plastics, combined with the use of beryllium- and lead-free metals for the contacts, thus avoid the use of hazardous or prohibited substances; the possibility of large axial misalignment, typically + / -1.2 mm, facilitated by the guidance of the sliding outer contact by the guide tube; the possibility of large radial misalignment on a PCB to be connected, typically + / -0.75 mm, through the end shapes of the sliding center and outer contacts and the sliding interlocking of the coaxial lines; the simplicity of the geometry of the connector components and their assembly; reduced component and assembly costs; and a high operating frequency due to the impedance stability of the coaxial lines.typically equal to 20 GHz with an impedance of 50 ohms.

[0054] Other advantages and features of the invention will become clearer upon reading the detailed description of examples of implementation of the invention given by way of illustration and not limitation with reference to the following figures. Brief description of the drawings

[0055] [ [Fig 1], [Fig 1A ], [ Fig 1B ] THE Figures 1, 1A , 1B represent, respectively in perspective and longitudinal sections, an example of a single coaxial connector according to a first embodiment of the invention, Figures 1A And 1B being carried out according to the same cutting plan but with a greater compression stroke for the figure 1B . [ Fig 2 ] there figure 2 is an exploded view of the connector according to the Figures 1 to 1B . [ Fig 3 ] there figure 3is a perspective view of an external contact of a coaxial line at one end of the connector according to the Figures 1 to 1B . [ Fig 4 ] there figure 4 is a perspective view of another connector subset comprising the three center contacts of the coaxial lines of the connector according to the Figures 1 to 1B . [ Fig 5 ] there figure 5 is a perspective and longitudinal sectional view of a connector subassembly comprising an external contact according to the figure 3 and a guide tube overmolded onto said contact. Fig 6 ] there figure 6 is a perspective and longitudinal cross-sectional view of a single coaxial connector according to an alternative embodiment of the invention. Fig 7 ] there figure 7 is a perspective view of an interconnect plate intended to be interposed between a longitudinal end of a single coaxial connector according to the invention and a PCB. Fig 8 ] there figure 8is a perspective view of a PCB equipped with a plurality of interconnecting plates according to the figure 7 for the implementation of a multi-way coaxial connection system. Fig 9 ] there figure 9 is a perspective view of a multi-way coaxial connection assembly comprising a plurality of unit coaxial connectors according to the invention arranged in parallel with each other and connected between a PCB and a PCB equipped with the plurality of interconnecting plates according to the figure 8 . [ Fig 10 ] there Figure 10 represents in longitudinal section an example of a single coaxial connector according to a second embodiment of the invention, intended to make an electrical connection between two PCBs, without soldering. Fig 11 ] there figure 11 is an exploded view of the connector according to the Figure 10 . Detailed description

[0056] We have represented on the figures 1 to 2, a single coaxial connector 1 according to a first embodiment of the invention, in its assembled configuration, in an intermediate deployed position.

[0057] Connector 1 extends along a longitudinal axis X, is assembled into a single object intended to transmit radio frequency (RF) signals.

[0058] This single coaxial connector essentially comprises three coaxial lines 2, 3, 4 adjacent along the longitudinal axis X, with their diameter increasing from one line to the next, from one longitudinal end 10 of the connector to the other 11 of its longitudinal ends. The increasing diameter of the coaxial lines allows for greater tolerance at one end of the coaxial connector 1 to radial misalignment with the device to be connected (PCB, filter, etc.).

[0059] These three lines 2, 3, 4 have constant nominal impedances along the length of each line. Preferably, the nominal impedances of all the coaxial lines are equal.

[0060] The coaxial line 2 includes an outer or ground contact 20 and a center contact 21 arranged inside the outer contact 20. The diameter of the center contact 21 is adapted to obtain a constant impedance, typically 50 ohms, over the entire length of the coaxial line 2.

[0061] The coaxial line 3 includes an external or ground contact 30, with a larger diameter than the external contact 20, allowing for improved contact continuity and therefore RF performance, and a central contact 31 arranged inside the external contact 30 and with a larger diameter than the central contact 21. The external contact 30 slides into the external contact 20. The central contact 31 is integral, preferably formed as a single unit with the central contact 21.

[0062] The coaxial line 4 comprises an external or ground contact 40, of larger diameter than the external contact 30 and a central contact 41 arranged inside the external contact 40 and of larger diameter than the central contact 31. The external contact 40 is integral, preferably formed integrally with the external contact 30.

[0063] As illustrated, the outer contact 40 preferably comprises, at its free end, two concentric flanges 400, 401, one inside the other forming two steps, with the outer one extending radially outwards. The inner concentric flange 401 allows the bearing surface of the outer contact 40 to be radially offset outwards from the ground of the PCB or filter. The outer concentric flange 400 creates the bearing surface of the outer contact against the ground of the PCB or filter. The flare formed by the two concentric flanges 400, 401 at the end of the outer contact increases the radial misalignment tolerance. The central contact 41 slides onto the central contact 31. The central contact 41 comprises, at its open end, petals 411 in mechanical and electrical contact with the outer surface of the central contact 31.The length of this central contact 41 is exactly that of the coaxial line 4 allowing a constant impedance of the latter.

[0064] As seen on the Figures 1A And 1B The volumes between the central contacts 21, 31, 41 and the external contacts 20, 30, 40 are filled with air, or with an electrically non-conductive gas, or consist of a vacuum, i.e. without solid electrical insulation over at least the sliding length along the longitudinal axis X. The absence of solid electrical insulation in the coaxial line 3 allows the external contact 20 to penetrate under the external contact 30, and the central contact 41 to slide around the central contact 31.

[0065] A guiding element 5, preferably in the form of a hollow tube, has an inner surface adapted to mechanically guide the external contact 40. As is apparent from the Figures 1A And 1BThis element, in the form of an outer guide tube 5, preferably overmolded onto the outer contact 20, acts as the mechanical structure of the connector. It therefore serves both to stiffen this outer contact 20, by virtue of its surrounding base 50, to protect all the outer contacts 20, 30, and 40, and to provide the mechanical robustness of the connector 1. Due to the significant axial travel of the outer contact 40, the guide tube 5 prevents deflection of the outer contact 40, particularly when it is fully extended.

[0066] The guide element 5 is distinct from each of the coaxial lines 2, 3, 4, in particular from each external contact 20, 30, 40 of each of the coaxial lines 2, 3, 4.

[0067] This guide tube 5 is advantageously made of an electrically insulating material selected from an aliphatic polyamide (PA), a liquid crystal polymer (PCL), polyetheretherketone (PEEK) or a mixture thereof.

[0068] The fully tubular shape of element 5 reduces the overall size of the connector. However, only its inner tubular surface is used for guidance; its outer shape can vary depending on the application or requirements.

[0069] The coaxial line 3 has a variable electrical length, due to the synchronous sliding of the ground contact 30 on the ground contact 20 and the sliding of the central contact 41 on the central contact 31.

[0070] The transition zones Z1 between coaxial lines 2 and 3 on the one hand, and Z2 between coaxial lines 3 and 4 on the other, have an invariant design, meaning that the diameter ratios between the ground contact and the center contact are equal, with a stable impedance, typically equal to 50 ohms, regardless of the deployed position, i.e., the sliding position of the coaxial lines of the connector. This allows the connector 1 according to the invention to operate above 12 GHz, preferably up to 20 GHz.

[0071] In the illustrated mode Figures 1 to 1B The single coaxial connector 1 includes: a first electrically conductive body 14 having two different diameters, forming respectively the central contact 21 of the coaxial line 2 and the central contact 31 of the coaxial line 3; a second electrically conductive body 15 forming the central contact 41 of the coaxial line 4 sliding on the central contact 31 of the coaxial line 3; a third electrically conductive body 12, forming the outer contact 20 of the coaxial line 2, the guide tube 5 being overmolded around it by its base portion 50; a fourth electrically conductive body 13 having two different diameters, forming respectively the outer contact 30 of the coaxial line 3 and the outer contact 40 of the coaxial line 4, the latter being mechanically guided by the guide tube 5.

[0072] A helical spring 6 is wound between the guide tube 5 on one side, and the external contacts 20 and 30 on the other, and axially abutted on one side against a shoulder of the guide tube 5 and on the other against the shoulder forming the junction between the external contact 30 and the external contact 40. This spring 6 ensures the sliding of the external body or mass 13 and the contact force with the PCB to which the longitudinal end 11 of the connector is intended to connect.

[0073] A helical spring 7 is housed in a bore 310 of the central contact 31 and axially abutted against the blind end 410 of a tube forming the central contact 41. This spring 7 ensures the movement of the central contact 41 and the contact force with the PCB to which the longitudinal end 11 of the connector is intended to connect.

[0074] These helical springs can be replaced by any other suitable elastic return means (spring washers, cut metal piece...).

[0075] There figure 3 Figure 12 shows the electrically conductive body that forms the external contact 20. The free end of this contact includes petals 200 which, via their outer faces, ensure electrical contact with the external contact 30 that slides over it. This configuration ensures better contact pressure.

[0076] The base of the body 12 advantageously features tabs 22 orthogonal to the X-axis, intended to serve as a permanent electrical and mechanical connection to a printed circuit board (PCB1), notably by soldering, enabling surface mounting using SMT technology. These tabs 22 could also be arranged parallel to the X-axis for through soldering to the PCB, or for press-fit mounting inside a hole in the PCB.

[0077] The body 12 also includes openings 23 at its base for forming the guide tube 5 by overmolding it onto the body 12. Advantageously, this overmolding of the outer tube 5 also allows for the simultaneous formation of an electrical insulating block 51, as illustrated in Figures 1A And 1B in which a smaller diameter portion of the central contact 21 is mechanically retained. The openings 23 are oblong through holes. Other shapes are possible depending on the technical constraints of overmolding the tube, and where applicable, the electrical insulating block.

[0078] The outer guide tube 5 preferably includes centering and / or mechanical retention feet 53 adapted for positioning and pre-assembling, preferably by press fitting or clipping, the tube and thus the connector to a printed circuit board (PCB1) to which the coaxial line 2 of the connector is intended to be connected by being secured, in particular by soldering. This pre-assembly can be carried out by press fitting or clipping. The number of centering and / or mechanical retention feet may vary depending on the technical constraints of mounting on the PCB.

[0079] Advantageously, the guide tube 5 also provides a mechanical retention and axial stop function for the outer body 13. To do this, the outer contact 40 includes outwardly oriented tabs or embossed parts 42 which each slide in a through opening 52 made in the guide tube 5 and can come to an axial stop against their edge.

[0080] The mechanical operation of the coaxial connector 1 is essentially as follows: when connecting two PCBs or a PCB to a filter or module, the connector 1 can compress between its two longitudinal ends 10 and 11 due to the reduction in length caused by the sliding of the coaxial cable 3. The outer or ground contact 30 slides outside the outer or ground contact 20, and the center contact 41 slides simultaneously on the center contact 31. Helical springs 6 and 7 provide the contact forces necessary for the electrical connection. The flanges 400 and 401 of the outer contact 40 allow for an increase in acceptable radial misalignment without affecting the impedance of the coaxial cable 4 of the connector, due to the short axial length of each flange.

[0081] In order to reach the folded connection position of connector 1, bodies 13 and 15 move essentially synchronously, in order to slide respectively on bodies 12 and 14, thus reducing the length of coaxial line 3.

[0082] In certain configurations of a connector 1 in contact with a PCB or filter, the rim 401 of the outer contact 40 and the end 410 of the center contact 41 may be significantly offset longitudinally. In other words, the rim 401 and the end 410 may not be coplanar.

[0083] When connecting connector 1 with this PCB or filter, the rim 401 and the end 410 come into contact with the respective surfaces facing the filter, mechanically pre-stressing the elastic elements 6 and 7.

[0084] Then, the connector 1 is folded between its two longitudinal ends 10 and 11 in order to reach its connection length by sliding the coaxial line 3. The outer ground contact 30 and the center contact 41 then slide simultaneously, respectively on the outer contact 20 and the center contact 31.

[0085] The assembly process for the single coaxial connector 1 just described comprises the following steps: i / supply of the third electrically conductive body 12 forming the external contact 20 ( figure 3); ii / supply of a fourth electrically conductive body 13 comprising two different diameters, forming respectively the outer contact 30 and the outer contact 40; iii / mechanical assembly of a first connector sub-assembly 17 comprising a first electrically conductive body 14 having two different diameters, forming respectively the central contact 21 and the central contact 31, and a second electrically conductive body 15 forming the central contact 41, sliding on the central contact 31 ( figure 4 ). This step iii / preferably includes housing the helical spring 7 in the bore 310 of the central contact 31, which is axially abutted against the free end 410 of the blind tube forming the central contact 41; iv / overmolding the guide tube 5 onto the third electrically conductive body so as to form a second connector subassembly 16 ( figure 5) then mechanical assembly of the first sub-assembly 17 in the second sub-assembly 16. Preferably, the central contact 21 is held in the central electrical insulator 51 formed by the overmolding; or iv' / overmolding of the guide tube 5 both on the third electrically conductive body 12 and on the central contact 21 of the coaxial line 2 of the first connector sub-assembly 17 so as to form a second connector sub-assembly; vi / mechanical assembly of the fourth electrically conductive body 13 in the second sub-assembly 16 so that the outer contact 30 slides on the outer contact 20 and the guide tube 5 mechanically guides the outer contact 40.Previously, the helical spring 6 is wound around the external contact 20 and, when the body 13 is inserted, comes into axial contact on one side against a shoulder of the guide tube 5 and on the other side against the shoulder forming the junction between the external contact 30 and the external contact 40.

[0086] Advantageously, electrically conductive bodies are obtained by stamping.

[0087] Alternatively, step iv' / can be carried out with overmolding of the central electrical insulator 51.

[0088] There figure 6This illustrates an alternative embodiment of the coaxial connector 1, which includes an electrically insulating block 8 arranged between the outer contact 40 and the center contact 41 of the third coaxial line 4 over at least part of its axial length, preferably along its entire axial length. If the insulating block 8 partially occupies the length of the coaxial line 4, impedance matching must be performed between the area containing the block and the area without solid insulation.

[0089] This electrically insulating block 8 comprises at least one axial through hole 80, preferably a plurality of holes regularly distributed angularly around the X-axis. This insulating block 8 improves the mechanical retention of the central sliding contact 41. The axial hole(s) along the length of the sliding coaxial line 4 reduce the dielectric constant compared to a solid body, bringing it closer to that of air. In this alternative configuration, the diameter of the sliding coaxial line 4 is increased compared to that without the insulating block 8.

[0090] The electrically insulating block 8 is preferably made of an electrically insulating material selected from an aliphatic polyamide (PA), a liquid crystal polymer (PCL), polyetheretherketone (PEEK) or a mixture thereof.

[0091] Finally, the electrically insulating block 8 is not fixed to both the outer contact 40 and the central contact 41, allowing slight relative axial sliding between these two contacts when pre-stressing against the PCB or the filter to be connected.

[0092] PCBs that need to be connected together by one or more coaxial connectors 1, as just described, may use fragile coatings that are incompatible with the support and friction forces of coaxial connectors 1. These coatings, typically tin-based, allow for cost savings.

[0093] To ensure adequate support and friction for establishing a reliable connection between a single coaxial connector 1 and a PCB, the inventors have provided an interconnection plate 9 as illustrated in the figure 7 The interconnection plate 9 simplifies the PCB and reduces manufacturing costs.

[0094] This interconnection plate 9 has a main face 90 intended to be connected, by being soldered, to a printed circuit board (PCB2), a module, or a filter. The other main face 91 is intended to be connected to the coaxial line 4 of the connector. It therefore has two concentric electrically conductive tracks 910 and 911 separated by electrical insulation. These tracks 910 and 911, intended to bear against the outer contact 40 and the central contact 41 respectively, may have a hard metallic coating, typically nickel-gold or silver alloy, which is compatible with the pressure applied by a coaxial connector 1.

[0095] Thus, an interconnection plate 9 allows the signal to be reliably routed between, on the one hand, the central contacts 21, 31, 41 and the signal track of PCB2 and, on the other hand, the outer contacts 20, 30, 40 of the coaxial connector 1 and the electrical ground of PCB2.

[0096] There figure 8 shows part of a 100 multi-way coaxial connection assembly with a PCB2 on which several interconnecting plates 9.1 to 9.8 are arranged and secured in parallel with each other.

[0097] There figure 9 shows the multi-way assembly 100 with a plurality of coaxial connectors 1.1 to 1.8, each connected by its coaxial line 2 to a PCB1 and to the PCB2 via its coaxial line 4 and an interconnection plate 9.1 to 9.8 secured as shown in the figure 8 .

[0098] THE Figures 10 And 11show a second embodiment of the unit coaxial connector 1 according to the invention, intended to be connected, without soldering or brazing, by its two ends to two PCBs.

[0099] The first electrically conductive body 14 here comprises two components, namely a cylindrical sleeve forming the central contact 31 and the central contact 21 with a free end in the form of a slotted socket 211 and a contact point 25, making the electrical connection between the central contact 21 and the printed circuit board PCB1, mounted axially movable in the sleeve 31, 21 with an axial stop made by an external shoulder 210 in an internal shoulder of the sleeve 31, 21.

[0100] The elastic element 7 exerts a force on the shoulder 210 of the contact tip 25, in order to ensure contact pressure with one of the two PCBs, such as PCB1.

[0101] The cylindrical sleeve 31, 21 is integral with the electrical insulating block 51, for example by being press-fitted into an opening in the insulator 51. The electrical insulator 51 is itself integral with the external contact 20.

[0102] The guide element 5 is integral with the external contact 20. The guide element 5 is electrically conductive to ensure electrical connection with the ground trace of the PCB1, via its base portion 50 in the form of a ring. Furthermore, given the more compact geometry of the connector in this second embodiment, the guide element 5 can advantageously be made of a metallic material, particularly by machining. The guide element 5 includes an internal surface that mechanically guides the external contact 40. The guide element 5 can also axially retain the external contact 40, notably by means of retaining tabs 500 at its free end, which engage with a shoulder of the external contact 40.

[0103] The contact tip 25, movable relative to the external contact 20 and therefore to the guide element 5, ensures the electrical signal connection with the PCB1 under all circumstances. The guide element 5 simultaneously provides the electrical ground connection with the PCB1.

[0104] The electrical signal passing through the sleeve 31, 21 is transmitted to the contact tip 25 via the petals of the split sleeve 211 at the free end.

[0105] The second body 15 is integral with the electrical insulator 8, notably by press fitting. The electrical insulator 8 is slidably mounted in the outer contact 40, which allows electrical connection both to the outer contact 40 with the ground trace of the other of the two PCBs, such as PCB2, and to the central contact 41 with the signal trace of PCB2.

[0106] The electrical insulator 8 is held axially in the external contact 40, in particular by means of tabs 402 of the latter which fit into an opening 81 of the insulator 8.

[0107] Thus, a single coaxial connector 1 according to this second embodiment, as illustrated in Figures 10 And 11 , establishes electrical contacts at each of these ends, solely by the force exerted by each of the elastic elements 6 and 7 with the signal and ground traces of PCB1 and PCB2. Therefore, no brazing or soldering is required.

Claims

1. Unitary coaxial connector (1), for connecting two parallel printed circuits (PCB1, PCB2) for transmitting radio-frequency, RF, signals, having a longitudinal axis X, comprising: - three coaxial lines (2, 3, 4) that are adjacent along the longitudinal axis X and increase in diameter from one adjacent line to the other, from one of the longitudinal ends (10) of the connector to the other of its longitudinal ends (11), each of the lines comprising a central contact (21, 31, 41) and an outer contact (20, 30, 40) arranged around the central contact, at least one central contact of a coaxial line being slidable into a central contact of one of the other lines adjacent thereto, at least one outer contact of a coaxial line being slidable into an outer contact of one of the other lines adjacent thereto so that the length of the intermediate coaxial line can vary, the volume between the central contact and the outer contact of the intermediate line being devoid of a solid electrical insulator, characterized in that the central contacts of the coaxial lines are formed by a first electrically conductive body (14) having at least two different diameters, forming the central contact (21) of a first coaxial line and the central contact (31) of a second coaxial line, respectively, and by a second electrically conductive body (15), forming the central contact (41) of a third coaxial line, which is slidable over the central contact of the second coaxial line, which has a greater diameter than that of the first coaxial line, the first electrically conductive body extending from one of the longitudinal ends (10) of the connector and the second electrically conductive body extending from the other of its longitudinal ends (11); - a guide element (5), preferably in the form of a hollow tube, the internal surface of which is suitable for mechanically guiding at least the outer contact of the coaxial line which extends from one of the longitudinal ends of the connector.

2. Unitary coaxial connector according to Claim 1, the second electrically conductive body comprising an open end comprising petals (411) in mechanical and electrical contact on the outer surface of the first electrically conductive body.

3. Unitary coaxial connector according to either of the preceding claims, the guide element being integral with the outer contact (20) of the coaxial line which extends from the other of the longitudinal ends of the connector, which is opposite to that from which the outer contact mechanically guided by the guide tube extends, the guide element preferably being integral with the smaller-diameter outer contact.

4. Unitary coaxial connector according to one of the preceding claims, the guide element also being suitable for mechanically retaining the outer contact (40) of the coaxial line, preferably for forming an axial stop for the latter.

5. Unitary coaxial connector according to one of the preceding claims, a single coaxial line being slidable into another coaxial line, the outer contact of the third coaxial line being integral with the outer contact of the second line with a narrowing in diameter.

6. Unitary coaxial connector according to Claim 5, comprising: - a third electrically conductive body (12), forming the outer contact (20) of the first coaxial line, which is integral with the guide element, preferably by being overmoulded therewith; - a fourth electrically conductive body (13) having two different diameters, forming the outer contact (30) of the second coaxial line and the outer contact (40) of the third coaxial line, respectively, the outer contact of the second coaxial line being slidable over the outer contact of the first coaxial line, the outer contact of the third coaxial line, which has a greater diameter than that of the second coaxial line, being mechanically guided by the guide element, the connector preferably comprising at least one elastic return means for returning the fourth electrically conductive body to an unfurled end position relative to the third electrically conductive body.

7. Unitary coaxial connector according to one of the preceding claims, comprising at least one elastic return means for returning the second electrically conductive body to an unfurled end position relative to the first electrically conductive body, the elastic return means preferably consisting of a helical spring (7) which is accommodated in a bore (310) in the larger-diameter central contact (31) of the first electrically conductive body and in axial abutment against the blind end (410) of a tube that forms the central contact (41) of the second electrically conductive body.

8. Unitary coaxial connector according to Claim 7 in combination with Claim 6, wherein: - the guide element (5) is electrically conductive and integral with the outer contact (20) formed by the third electrically conductive body; - the first electrically conductive body (14) comprises a cylindrical sleeve that forms the central contacts (31, 21) of the first and second coaxial lines and a contact tip (25) mounted so as to be axially mobile in the sleeve (31, 21) with an axial stop; - the second electrically conductive body (15) that forms the central contact (41) of the third coaxial line being mounted so as to be slidable relative to the fourth electrically conductive body (13) that forms the outer contact (30) of the second coaxial line and the outer contact (40) of the third coaxial line, in such a way that the force exerted by each of the elastic return means (6, 7) can produce the electrical connection between, firstly, at one of the longitudinal ends (10) of the connector, the contact tip and the guide element and, respectively, the signal track and the earth track of a first printed circuit board (PCB1) and, secondly, at the other of the longitudinal ends (11) of the connector, the central contact (41) and the outer contact (40) of the third coaxial line and, respectively, the signal track and the earth track of a second printed circuit board (PCB2).

9. Unitary coaxial connector according to one of Claims 6 to 8, comprising an electrically insulating block (8) arranged between the outer contact (40) and the central contact (41) of the third coaxial line over at least a portion of the axial length thereof, the electrically insulating block comprising at least one axial through-hole (80).

10. Unitary coaxial connector according to one of the preceding claims, except Claim 8, the guide element being made of an electrically insulating material chosen from an aliphatic polyamide (PA), a liquid crystal polymer (LCP), polyetheretherketone (PEEK) or a mixture thereof.

11. Unitary coaxial connector according to one of the preceding claims, the material from which the contacts are made being a copper alloy devoid of lead and beryllium.

12. Unitary coaxial connector according to one of the preceding claims, except Claim 8, the outer contact (20) of one of the coaxial lines at one longitudinal end of the connector comprising at least one lug (22) intended to be used for permanent electrical and mechanical connection to a printed circuit board (PCB1).

13. Unitary coaxial connector according to one of the preceding claims, the outer contact (40) of one of the coaxial lines at one longitudinal end of the connector comprising, at its free end, two concentric flanges (400, 401), one inside the other to form two staircase steps, the outer flange of which extends radially outwards.

14. Coaxial connector assembly (100), configured to connect two parallel printed circuit boards (PCB1, PCB2), comprising: - at least one unitary coaxial connector (1) according to any one of the preceding claims, of which one of the coaxial lines (2) at one longitudinal end (10) of the connector is intended to be connected by being secured, in particular soldered, to a first printed circuit (PCB1), - at least one interconnection plate (9), one main face of which is intended to be connected by being secured, in particular soldered, to a second printed circuit (PCB2), and the other main face of which is intended to be connected to another of the coaxial lines (4) at the other longitudinal end (11) of the connector.

15. Method for producing a unitary coaxial connector according to Claim 6 or one of Claims 7 and 9 to 13 in combination with Claim 6, comprising the following steps: i / supplying the third electrically conductive body that forms the outer contact of a first coaxial line; ii / supplying the fourth electrically conductive body having two different diameters, forming the outer contact of a second coaxial line and the outer contact of a third coaxial line, respectively, iii / mechanically assembling a first connector subassembly comprising the first electrically conductive body having at least two different diameters, forming the central contact of the first coaxial line and the central contact of the second coaxial line, respectively, and the second electrically conductive body that forms the central contact of the third coaxial line, which is slidable over the central contact of the second coaxial line, which has a greater diameter than that of the first coaxial line; iv / overmoulding the guide element on the third electrically conductive body to form a second connector subassembly and then mechanically assembling the first subassembly in the second subassembly; or iv / ' overmoulding the guide element both on the third electrically conductive body and on the central contact of the first coaxial line of the first connector subassembly to form a second connector subassembly; v / mechanically assembling the fourth electrically conductive body in the second subassembly so that the outer contact of the second coaxial line slides over the outer contact of the first coaxial line and that the guide element mechanically guides the outer contact of the third coaxial line.