Ultra-compact and ultra-high frequency inter-board coaxial connection system

Abstract

The present invention relates to a coaxial connection system (1) for transmitting a high-frequency (RF) signal, suitable for connecting two printed circuit boards (PCB1, PCB2), suitable for connecting one board to a filter, or suitable for connecting one board to a module. [Solution] This system is a kind of hybrid ultra-compact and ultra-high frequency inter-board coaxial connection system that includes a spring-type adapter (4), the connection interface of which the adapter has radial electrical contact for the outer contacts (42, 43) and axial electrical contact at the ends for the central contacts (40, 41).

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of electrical connections, and concerns a radio frequency (RF) coaxial connection system. More specifically, the present invention relates to a coaxial connection system for transmitting RF signals from a radio board to a substrate that supports radiating elements of an electronically scanned antenna for telecommunications and radar systems.

[0002] The present invention mainly aims to provide a new and innovative solution that has not been solved by existing solutions already commercialized as SMP-MAX, SMPM spring bullet, IMP-HD, IMP-SR series, etc., addressing the cumulative problems of compact size, substrate positioning tolerances in the three X, Y and Z axes, and stability of RF performance corresponding to higher frequencies in the X band for cellular communication systems or the Ka band for AESA (abbreviation of Active Electronically Scanned Array) radar applications.

[0003] Such systems can be used in particular to connect two printed circuits that are parallel to each other or orthogonal to each other (usually referred to as board-to-board (B2B) connections or printed circuit board (PCB) connections) to other components such as modules or filters, and these connections are generally referred to as board filter connections or board module connections.

[0004] The application that the present invention is particularly directed to is the connection of telecommunications equipment.

[0005] The present invention also generally relates to interconnection systems in the fields of telecommunications, medical care, industry, aviation, transportation and space.

[0006] The system according to the present invention can be used, in particular, to connect two parallel or orthogonal printed circuits (commonly referred to as board-to-board connections or printed circuit board connection systems) to other components such as modules, filters, power amplifiers, or antennas, or to connect modules to each other.

[0007] An "RF connection system" refers to a system capable of transmitting signals across a range from the direct current (DC) domain to the radio frequency (RF) domain (including the microwave (HF) domain), and these signals are either high-speed data link (HSDL) digital signals or radio frequency (RF) signals. [Background technology]

[0008] With the continuous development of wireless communication technology, board-to-board connectors are increasingly being used in the interconnection of wireless system modules, such as communication base stations, RRHs, repeaters, GPS equipment, and other similar applications. The top three trends in wireless equipment are miniaturization, cost reduction, and ease of installation, as well as the increasing frequency of RF signals used. In board-to-board connections as well, the market demands miniaturization, cost reduction, and modularization of boards.

[0009] Examples of connection assemblies for the telecommunications sector for the interconnection of cellular radiotelephones already exist in the market and in the prior art. This is because the trend in this market is to minimize losses in the high-frequency portion in order to reduce the number of amplifier components in base stations. For this reason, firstly, the radio portion of the base station is increasingly being placed as close as possible to the transmit and receive antennas in the RRU / RRH transmit module, and secondly, RF cables inside the radio unit are being replaced with direct connections.

[0010] So-called inter-board connections have evolved through generations in this way over the past decade.

[0011] Commercially available products already exist to enable these connections.

[0012] Current solutions for transmitting RF signals between two substrates can be classified into three types.

[0013] The first type consists of a slide base, a snap-in base, and an adapter, and is a system that allows for axial and radial tolerances. Many interconnects of this type exist on the market, mainly for the telecommunications market, particularly for wireless heads in 4G / 5G cellular networks, and include the SMP-MAX, Power-Max Ultra, RSMP, HSMP, and P-SMP series.

[0014] The limitation of this type of interconnect is the large impedance variation in the overlapping region between the slide base and the adapter, which limits the RF performance to the DC to 6GHz band. Therefore, this type of interconnect cannot exceed 10GHz under any circumstances unless the axial tolerance is significantly reduced.

[0015] You can refer to European Patent No. 2304852, which relates to an SMP-Max series connector having a dumbbell-shaped electrical insulator and having a bandwidth limited by the high impedance region being compensated by a low impedance region.

[0016] The second type is a floating system that includes a spring-loaded adapter, which makes it possible to solve the problem of impedance fluctuations in the overlapping region between the slide base and the adapter. In fact, a spring with constant impedance can maintain contact between the reference planes of the base and the adapter, regardless of the distance between the two substrates.

[0017] This type of interconnection system is applied to the SMP and SMPM series under the name "Spring Bullet," as disclosed in U.S. Patent No. 11,539,167.

[0018] The limitation of this system is its low compactness, resulting from the combination of the receptacle and the constant impedance spring, with the required space increasing by at least three times due to axial tolerances. Furthermore, the pin and socket type center contacts significantly limit the rotation of the so-called "spring bullet" to just a few degrees, and the acceptable radial misalignment is also severely limited. This radial misalignment can only be increased by increasing the length of the spring bullet.

[0019] The third type is a system that interconnects by pressure at the ends of the contacts.

[0020] To improve axial compactness, systems have been developed that apply direct axial pressure to printed circuit boards. The most well-known examples are the IMP-HD and IMP-LP connectors. This type of interconnect system allows for a significant improvement in axial compactness by eliminating the need for slide bases and snap-in bases.

[0021] However, this system does not tolerate parallelism errors, and the radial tolerance between substrates is extremely small. This is because the center and outer contacts are offset from their respective target positions. Furthermore, this offset results in a significant decrease in RF performance.

[0022] In recent years, with the advancement of high-density infrastructure, there is an increasing need to reduce footprints.

[0023] For telecommunications applications, the required length between two interconnected circuit boards is approximately 11 mm, and the diameter is approximately 4 mm. For radar applications, in the case of a spring-type system, the required length, including the spring, decreases to approximately 7.5 mm, and the diameter shrinks to approximately 2 mm.

[0024] Furthermore, with the increase in signal frequency, especially in the X-band (i.e., 8 to 12 GHz) for telecommunications applications, and the Ka-band (i.e., 27 to 31 GHz) and V-band (i.e., 40 to 75 GHz) in products for electronic scanning antennas, impedance mismatch must be dimensionally reduced or eliminated to avoid affecting signal transmission. However, the requirements for axial and radial positional deviation remain stringent.

[0025] Accordingly, there is a need to further improve inter-board connections, inter-substrate module connections, or inter-substrate filter connections, and more specifically, at very high frequencies such as X, K and V bands, while maintaining high RF performance corresponding to the interface with the electrical reference plane in contact with the substrate, it is necessary to solve the problem of large axial and radial positional deviations and achieve a connection that is extremely compact in the length direction.

[0026] The present invention aims to address all or part of these requirements. SUMMARY OF THE INVENTION

[0027] For this purpose, the present invention, according to one aspect thereof, relates to a coaxial connection system for transmitting radio frequency (RF) signals, which is suitable for connecting two printed circuit boards (PCB1, PCB2), suitable for connecting one substrate to a filter, or suitable for connecting one substrate to a module, the system having a longitudinal axis X, - two annular receptacles or annular rings, each configured to be in mechanical and electrical contact with one of the ground traces of the substrate, filter or module, - a spring-loaded adapter, two central contacts that slide relative to each other, and Two outer contacts that slide relative to each other, each of the two outer contacts being mechanically guided by one of the two annular receptacles and the annular ring, arranged coaxially around one of the two central contacts, and mechanically held, a spring-loaded adapter comprising a coil spring arranged around the two outer contacts, comprising, each of the two central contacts is configured to ensure electrical continuity by axial mechanical pressure at its free end, and each of the two outer contacts is configured to ensure electrical continuity by radial deformation of its free end.

[0028] "Electrical continuity" means that the electrical path for current is continuous through the connection system.

[0029] Advantageously, the outer contact is configured not to make mechanical contact with the two printed circuit boards (PCB1, PCB2), the substrate and the filter, or the substrate and the module.

[0030] Also advantageously, the central contact is configured to make direct mechanical and electrical contact with the two printed circuit boards (PCB1, PCB2), the substrate and the filter, or the substrate and the module by the free end of the central contact.

[0031] Preferably, the free end of each central contact has a partial spherical shape. In other words, the free end is shaped as a partial spherical surface.

[0032] According to an advantageous variant embodiment, the free end of each of the outer contacts is slotted to define contact pieces each having a bump formed at the front end thereof. The contact pieces deform radially, such that the bumps define an electrical contact surface.

[0033] According to another advantageous embodiment, the system comprises four impedance lines, each of the two end lines including an electrical insulator interposed and held between one of the two center contacts and the two outer contacts, and each of the two internal lines not having a solid electrical insulator.

[0034] Preferably, the diameter of one of the central contact points decreases from the free end of at least one end line toward the intermediate line.

[0035] Preferably, the outer diameter of the outer contact at the end line is larger than the outer diameter of the outer contact at the intermediate line.

[0036] According to another advantageous embodiment, one of the two receptacles is slide-type and the other is snap-on-type.

[0037] At least one of the outer contacts may have at least one lug used for permanent electrical and mechanical connection to printed circuit boards (PCB1, PCB2).

[0038] Preferably, at least one receptacle houses an O-ring or annular spring that holds one of the two outer contacts. The O-ring or annular spring allows for axial straightening of the adapter.

[0039] According to an advantageous embodiment, each of the receptacles houses a cavity filter.

[0040] In a favorable embodiment, one of the two receptacles is combined with a terminal to form a vertical board-to-board connection called an edge card.

[0041] In another embodiment, the annular ring is mechanically held by the outer contacts, thereby combining with the adapter. In this embodiment, the system consists solely of the adapter that holds the annular ring, ensuring that the annular ring makes electrical contact with the ground wiring of the printed circuit board or module.

[0042] The present invention also relates to a connection module used to connect two printed circuit boards (PCB1, PCB2), wherein the connection module is: - A coaxial connection system comprising an adapter configured as described above, - The adapter is housed by a floating mounting and comprises a holder having a frame with at least one opening.

[0043] According to an advantageous embodiment, the frame comprises a plurality of openings arranged parallel to each other, and one of the adapters is housed in each of the plurality of openings by floating mounting.

[0044] Therefore, the present invention essentially consists of a high-frequency (RF) coaxial connection system equipped with a spring-type adapter, and the adapter's connection interface is a kind of hybrid in that the outer contacts are electrically contacted radially, and the central contacts are electrically contacted axially at the ends.

[0045] The adapter's coil spring generates a compressive force, first creating an electrical connection between the tip of one center contact and the radial end of one outer contact at one end of the connection system in the longitudinal direction, and the signal line and ground line of the first printed circuit board (PCB1), respectively. Next, at the other end of the connection system in the longitudinal direction, it creates an electrical connection between the tip of the other center contact and the radial end of the other outer contact, respectively, and the signal line and ground line of a second printed circuit board (PCB2) parallel to the first printed circuit board (PCB1), an RF module, or another printed circuit board (PCB3) orthogonal to the first printed circuit board (PCB1).

[0046] Preferably, the ends of the two central contacts, each configured to contact the PCB, protrude from the corresponding ends of the outer contacts. This ensures permanent mechanical contact of the central contacts even if potential radial displacement or tilt angles occur.

[0047] The combination of radially contacting outer contacts and tip contacting central contacts allows the interface to maintain its center position in its mating position and to allow large rotations, typically accommodating inclination angles exceeding 10°, compared to conventional interfaces with pin-socket type centerline connections.

[0048] The mechanical and electrical reference surfaces are formed by the surfaces of the printed circuit board that are in contact with either the receptacle or the ring.

[0049] According to an advantageous embodiment, the system includes four coaxial impedance lines, with two end lines containing solid insulators, while two intermediate lines that slide against each other are insulated by air.

[0050] The characteristic impedance of each coaxial line and the entire connection system is maintained at a stable value, typically 50 ohms, throughout the entire length of the connection system, regardless of the final distance between the PCBs connected by the system. It is also possible to obtain a stable impedance of 75 ohms or any other arbitrary value throughout the entire length of the connector.

[0051] No impedance mismatch occurs when transitioning from one coaxial line to another along the axial direction of the connection system. In other words, the presence of air as the primary element within the coaxial line avoids the impedance fluctuations between the solid insulation region and the air insulation region seen in conventional connectors.

[0052] This invention offers many advantages over conventional coaxial connection systems.

[0053] - Extremely compact in the longitudinal direction, while tolerating large axial and radial misalignments at very high frequencies (typically X-band for low-cost communication products, and Ka-band and V-band for electronically scanning antenna products) while maintaining excellent RF performance.

[0054] - The impedance of the coaxial lines of the connection system formed according to the distance between PCBs is stable and typically maintained at 50Ω.

[0055] - It must maintain a simple structure with a limited number of parts and a quick and easy assembly process.

[0056] Other advantages and features of the present invention will become clearer by reading the detailed description of exemplary embodiments of the invention shown as non-limiting examples with reference to the following drawings. [Brief explanation of the drawing]

[0057] [Figure 1] Figure 1 is a longitudinal cross-sectional view showing an example of a coaxial connection system according to the first embodiment of the present invention, illustrating a configuration in which two parallel PCBs are connected without radial misalignment. [Figure 2] Figure 2 is a side view of the connection system shown in Figure 1, illustrating a configuration where two parallel PCBs are connected with a radial misalignment. [Figure 2A] Figure 2A is a longitudinal cross-sectional view of the connection system in Figure 1, showing a configuration where two parallel PCBs are connected with a radial misalignment. [Figure 3] Figure 3 is a perspective view of the spring-type adapter of the system shown in Figures 1 and 2. [Figure 4] Figure 4 is a perspective view of one of the receptacles of the system shown in Figures 1 and 2. [Figure 5] Figure 5 is a perspective view of the other receptacle of the system shown in Figures 1 and 2. [Figure 6]Figure 6 shows simulation curves of reflection loss as a function of frequency for various configurations of axial, radial, and parallelism tolerances between two PCBs using the system according to the present invention. [Figure 7] Figure 7 shows a modified receptacle including a cavity filter. [Figure 8] Figure 8 is a perspective view showing the receptacle, modified according to Figure 6, placed on a PCB. [Figure 9] Figure 9 is a perspective view of a modified receptacle with terminals that allow connection between a first PCB and another PCB positioned perpendicular to the first PCB. [Figure 10] Figure 10 is a perspective view of a connection system with a receptacle according to a modified example of Figure 9, showing a configuration in which a connection is made between a first PCB and another PCB positioned perpendicular to the first PCB. [Figure 11] Figure 11 shows a perspective view of a modified dual receptacle with a common terminal that allows connection between a first PCB and another PCB positioned perpendicular to the first PCB. [Figure 12] Figure 12 is a perspective view of two spring-loaded adapters with dual receptacles, relating to a modified example of Figure 10. [Figure 13] Figure 13 is a perspective view of an example of a coaxial connection system according to a second embodiment of the present invention, in which the receptacle is replaced by an annular ring mechanically held by an adapter. [Figure 14] Figure 14 shows a longitudinal cross-sectional view and perspective view of an example of the coaxial connection system shown in Figure 13. [Figure 15] Figure 15 is a perspective view of a multi-channel coaxial connection system that connects two parallel PCBs by arranging multiple coaxial spring adapters, as shown in Figures 13 and 14, parallel to each other and housing them in a holder. [Modes for carrying out the invention]

[0058] Figures 1 and 2 show a coaxial connection system 1 according to the first embodiment of the present invention, configured to be connected between two parallel PCBs 1 and 2.

[0059] The connection system 1 extends along the longitudinal axis X and is intended to transmit radio frequency (RF) signals. More specifically, it is intended to transmit signals in the X-band for communication applications, or in the Ka-band and V-band for electronic scanning antenna products.

[0060] System 1 first comprises two annular receptacles 2 and 3, each receptacle configured to make mechanical and electrical contact with one ground wire of the substrate, PCB 1 or PCB 2.

[0061] In the illustrated embodiment, receptacle 2 is a sliding type, and receptacle 3 is a snap-on type.

[0062] A spring-loaded adapter 4 is positioned between the two receptacles 2 and 3.

[0063] As shown in detail in Figures 1 and 3, the adapter 4 includes two central contacts 40 and 41 that slide and mate with each other. More precisely, the central contact 40 is male, with one end sliding and mating into the female central contact 41. Each of the central contacts 40 and 41 has a free end having a spherical portion shape 400 and 410. These spherical portions 400 and 410 allow for axial contact with the signal wiring of the respective substrates PCB1 and PCB2.

[0064] The two outer contacts 42 and 43 slide against each other. Each of the two outer contacts 42 and 43 is mechanically guided by one of the two annular receptacles 2 and 3, and is coaxially positioned around one of the two central contacts 40 and 41, and is mechanically held.

[0065] A slot is formed at the free end of each of the outer contacts 42 and 43, thereby defining contact petals, and each contact petal has a shape with bumps 420 and 430 at its front end.

[0066] The coil spring 44 is positioned around the central portion of the two outer contacts 42 and 43 and abuts against their ends. This coil spring 44 applies compressive force to create an electrical connection. To improve the compactness of the adapter, its outer diameter is not larger than the maximum outer diameter of the ground contact.

[0067] The two receptacles 2 and 3 guide the spring-loaded adapter 44 and also serve to ensure electrical contact between the printed circuit boards PCB1 and PCB2 and the outer contacts 42 and 43 of the adapter 4.

[0068] According to the present invention, the two central contacts 40 and 41 are configured to ensure electrical continuity through axial mechanical pressure at their free ends 400 and 410, while each of the two outer contacts 42 and 43 is configured to ensure electrical continuity through radial deformation at its free ends 420 and 430. This combination of two different types of electrical contact, namely axial contact by the contact tips 400 and 410 at the central contacts and radial contact by the bumps 420 and 430 at the outer contacts, allows the interface of system 1 to be held centrally in its receiving position while also benefiting from large rotations, typically of an angle greater than 10°.

[0069] Preferably, the free ends 400 and 410 of the central contacts 40 and 41 each protrude from the free ends of the corresponding outer contacts 42 and 43. This ensures that mechanical contact between the central contacts and the signal lines of the substrates PCB1 and PCB2 is always maintained, regardless of any radial displacement or tilt angle.

[0070] Preferably, the respective ends 400 and 410 of the central contacts 40 and 41 are formed in a spherical shape. This ensures that electrical contact between the central contacts and the signal lines of the substrates PCB1 and PCB2 is always and stably maintained, regardless of any radial displacement or tilt angle.

[0071] As shown in Figure 2A, even under maximum compression conditions with a tilt angle, the radial electrical contact between the outer contacts 42 and 43 of the adapter 4 and the receptacles 2 and 3 is maintained in close proximity to the surfaces of the substrates PCB 1 and PCB 2, thereby significantly limiting the impedance mismatch area and not affecting signal integrity. This electrically effective area depends only on the axial tolerance and the maximum allowable tilt angle, i.e., this area is thin.

[0072] The heights of receptacles 2 and 3 are designed to limit angular variation and allow only the adapter 4 to be guided during mating.

[0073] Figure 4 shows the conductive body 20 that forms the sliding receptacle 2. The base of the body 20 has lugs 21 which are advantageously perpendicular to the axis X, and these are intended for use in permanent electrical and mechanical connections to a printed circuit board (PCB 1), in particular enabling surface mounting according to SMT technology by soldering. These lugs 21 can also be positioned parallel to the axis X for through-hole soldering to the PCB, or they can be press-fitted into holes in the PCB. The large flare 22 on the top of the body 20 mechanically guides the adapter 4 during blind mating.

[0074] Figure 5 shows a conductive body 30 forming a snap-on receptacle 3. The base of the body 30 has lugs 31 which are advantageously perpendicular to the axis X, and these are intended for use in permanent electrical and mechanical connections to a printed circuit board (PCB 2), in particular enabling surface mounting according to SMT technology by soldering. These lugs 31 can also be positioned parallel to the axis X for through-hole soldering to the PCB, or they can be press-fitted into holes in the PCB. The body 30 houses an O-ring 32 which straightens the tilted adapter 4 if the receptacle 3 becomes detached from the printed circuit board PCB 2.

[0075] Receptacles 2 and 3 are made of a conductive material such as brass. In a modified version, the receptacle is made of a polymer material such as liquid crystal polymer (LCP). In this case, only the electrical contact area with the outer contacts of the adapter, i.e., the inner end adjacent to the PCB, is metallized to ensure electrical contact.

[0076] This structure ensures that the adapter 4 remains in constant contact with the mechanical and electrical reference planes P defined by PCB1 and PCB2.

[0077] In the illustrated embodiment, the connection system 1 comprises four coaxial impedance lines L1 to L4. The characteristic impedance of each coaxial line L1 to L4 and the entire connection system maintains a stable value of 50 ohms along the entire length of the connection system.

[0078] Each of the two end lines L1 and L4 includes an electrical insulator 45, 46 interposed between one of the two central contacts 40, 41 and the two outer contacts 42, 43, and mechanically held.

[0079] These insulators 45 and 46 are low dielectric loss insulators and allow the male center contact 40 and female center contact 41 to be held. These insulators are made of, for example, PTFE. As shown in the figure, these bodies 45 and 46 preferably include through holes 47, which allow for precise adjustment of the line impedance.

[0080] The outer diameter of the center contact 40 in coaxial line L1 is larger than the diameter in line L2 or L3. This makes it easier to insert the contacts of the main body during the assembly stage.

[0081] Lines L1 and L4 are preferably the same size, providing symmetry to the adapter 4. This also limits the number of different parts included in the system and simplifies its structure.

[0082] Each of the two internal lines L2 and L3 lacks a solid electrical insulator; that is, air acts as the insulator in these lines.

[0083] Lines L2 and L3 slide against each other internally; line L2 has a fixed length, while line L3 has a variable length. The stroke of line L3 defines the maximum allowable axial displacement. Regardless of the length of line L3, its characteristic impedance is maintained constant.

[0084] In these internal coaxial lines L2 and L3, the outer contact 42 has a male central portion 421 that fits into the female central portion 431 of the outer contact 43. The male outer contact 42 is equipped with an outwardly extending claw 422, which works in cooperation with the internal shoulder 432 of the female outer contact 43 to hold the two central portions 421, 422 engaged with each other regardless of the separating force applied by the compression spring 44.

[0085] To achieve a constant impedance of 50 ohms, the relative permittivity of the insulators 42 and 43 of lines L1 and L4 is defined as follows: - The diameters of lines L2 and L3 are significantly smaller than the diameters of lines L1 and L4, allowing for the insertion of the coil spring 44. The coil spring 44 generates a compressive force greater than the insertion force of the contact pieces defining the bumps 420 and 430 of the main bodies 42 and 43, and greater than the sliding force of the internal portions 421 and 431 and the central contacts 40 and 41 of the outer contacts 42 and 43. - The diameter of the male center contact point 40 in line L1 is the maximum diameter, allowing for easy insertion from the outside. - The diameter of the male center contact 40 is large enough to function as the framework for the entire system.

[0086] More specifically, the male center contact 40 has at least three different diameters, which makes it possible to maintain an impedance of 50 ohms in lines L1, L2, and L3 regardless of the compression state of the variable line L3.

[0087] As already mentioned, the structure, which has two sliding lines L2 and L3 insulated by air, makes it possible to maintain a constant impedance regardless of the relative positions of the substrates PCB1 and PCB2.

[0088] The inventors successfully confirmed that the impedance of such a system 1 remains constant by simulating the reflection loss as a function of axial, radial, and parallelism tolerances between two PCBs, using a model optimized for Ka-band signals, as shown in Figure 6. In Figure 6, the black nominal curve is simulated with no slope and nominal compression. The gray curve corresponds to configurations with slope and / or additional compression. Compared to the black nominal curve, the overall increase in loss in the gray curve is kept low, and even in configurations with maximum slope and / or maximum compression, the maximum loss is maintained below -20 dB (decibels), especially at very high frequencies.

[0089] In advantageous modifications, guide and electrical continuity receptacles can be adapted to accommodate cavity filters.

[0090] Therefore, Figure 7 shows a conductive body 50 that forms a sliding receptacle 5 including a cavity filter 52. The base of the body 50 has lugs 51 which are advantageously orthogonal to the axis X, and are used for permanent electrical and mechanical connections to a printed circuit board (PCB 1), in particular enabling surface mounting according to SMT technology by soldering. These lugs 51 can also be positioned parallel to the axis X and soldered through holes to the PCB, as shown in Figure 8, or they can be press-fitted into holes in the PCB.

[0091] Other receptacles 6 can be manufactured in the same way as slide-type receptacles 5.

[0092] As shown in Figure 8, the electrical conductivity of receptacles 5 and 6 is achieved only within a very low height of the receptacles, typically less than 1 mm. The remaining height serves to limit the permissible angular variation and facilitate easy mating during blind mating of adapter 4. Thus, the mismatch area on the PCB surface is minimized so as not to interfere with the transmission of high-frequency signals, and this mismatch area only allows for radial displacement. By separating this electrical function from the mechanical parts, it becomes possible to directly mount the electrical function on the filter or RF module panel, resulting in a significant reduction in interconnection costs.

[0093] Figure 9 shows another modification of the snap-on receptacle 7. The conductive body 70 includes terminals 71 supported by a block 73, to which the terminals 71 are electrically connected. This allows system 1 to connect substrate PCB 1 to another substrate PCB 3 (commonly called an “edge card”) positioned perpendicular to PCB 1, as shown in Figure 10. Similar to the previously described embodiment, the body 70 can also accommodate an O-ring 72.

[0094] Figure 11 shows a modified example supported by a common block 73, preferably having two identical snap-on receptacles 7.1, 7.2, which allows system 1 to achieve connection with an edge card.

[0095] Figure 12 shows a configuration in which each of two identical adapters 4.1 and 4.2 is attached to each of two snap-on receptacles 7.1 and 7.2, respectively.

[0096] Figures 13 and 14 show another embodiment of the present invention in which receptacles 2, 3 or 5, 6 are replaced by annular rings 8, 9 that are directly fixed to the adapter 4 by contact pieces of outer contacts 40, 41.

[0097] In other words, in this alternative embodiment, the adapter 4 constitutes the entire interconnection system 1 by itself.

[0098] In this alternative embodiment, electrical conductivity on the central side is always ensured by the free ends 400, 410 having a spherical portion shape of the central contacts 40, 41, while electrical conductivity on the outer side is ensured by the radial deformation of the bumps 420, 430 of the outer contacts 42, 430, which are in direct contact with the annular rings 8, 9, respectively.

[0099] The annular rings 8 and 9 are configured to make direct contact with the ground lines of the interconnected substrates PCB1 and PCB2.

[0100] By using multiple adapters 4 to fix the annular rings 8 and 9, it is possible to realize a connection module used to connect two printed circuit boards PCB1 and PCB2, and this connection module comprises the following:

[0101] Therefore, as shown in Figure 15, a holder is provided with a frame 10 having multiple openings arranged parallel to each other, and one of the adapters constituting systems 1.1 to 1.16 is housed in a floating mounting manner in each opening. This holder can be made very compact. For example, the dimensions L × H of such a holder 10 can be 9 mm × 6.35 mm for 16 adapters.

[0102] Other modifications and improvements can be provided without departing from the scope of the present invention.

Claims

1. A coaxial connection system (1) for transmitting high-frequency (RF) signals, suitable for connecting two printed circuit boards (PCB1, PCB2), suitable for connecting one board to a filter, or suitable for connecting one board to a module, Having a longitudinal axis X, - Two annular receptacles (2, 3, 5, 6) or annular rings (7, 8), each configured to make mechanical and electrical contact with one of the ground connections of a substrate, filter, or module, - A spring-type adapter (4), Two central contact points (40, 41) that slide against each other, Two external contacts (42, 43) that slide against each other, each of the two external contacts being mechanically guided by one of the two annular receptacles and the annular ring, and being coaxially arranged around one of the two central contacts and mechanically held, A coil spring (44) is arranged around the two outer contacts, A spring-type adapter including, Equipped with, Each of the two central contacts is configured to ensure electrical conductivity by axial mechanical pressure at its free end, and each of the two outer contacts is configured to ensure electrical conductivity by radial deformation at its free end. Coaxial connection system (1).

2. The coaxial connection system (1) according to claim 1, wherein the outer contact is configured not to mechanically contact two printed circuit boards (PCB1, PCB2), the board and the filter, or the board and the module.

3. The coaxial connection system (1) according to claim 1 or claim 2, wherein the center contact is configured to make direct mechanical and electrical contact with two printed circuit boards (PCB1, PCB2), the board and the filter, or the board and the module by the free end of the center contact.

4. The coaxial connection system (1) according to claim 3, wherein the free end is formed as a spherical portion.

5. The coaxial connection system (1) according to any one of claims 1 to 4, wherein each of the free ends of the outer contacts is provided with a slot, and a contact piece with a bump formed at the front end of each is defined.

6. It has four impedance lines (L1 to L4), Each of the two end lines includes an electrical insulator interposed and held between one of the two central contacts and the two outer contacts. Each of the two internal lines does not have a solid electrical insulator. A coaxial connection system (1) according to any one of claims 1 to 5.

7. The coaxial connection system (1) according to claim 6, wherein the diameter of one of the central contacts decreases from the free end of at least one end line (L1) toward the intermediate lines (L2, L3).

8. The coaxial connection system (1) according to claim 6 or claim 7, wherein the outer diameter of the outer contacts in the end lines (L1, L4) is larger than the outer diameter of the outer contacts in the intermediate lines (L2, L3).

9. The coaxial connection system (1) according to any one of claims 1 to 8, wherein one of the two receptacles is of the sliding type and the other is of the snap-on type.

10. A coaxial connection system (1) according to any one of claims 1 to 9, wherein at least one receptacle houses an O-ring or annular spring that holds one of the two outer contacts.

11. The coaxial connection system (1) according to claim 10, wherein each of the receptacles houses a cavity filter.

12. The coaxial connection system (1) according to any one of claims 8 to 11, wherein one of the two receptacles is combined with a terminal to form a vertical inter-board connection called an edge card.

13. The coaxial connection system (1) according to any one of claims 1 to 7, wherein the annular ring is mechanically held by the outer contact and thereby combined with the adapter.

14. A connection module used to connect two printed circuit boards (PCB1, PCB2), - A coaxial connection system comprising at least one adapter as described in claim 13, - A holder having a frame with at least one opening in which the adapter is housed by floating mounting, A connection module equipped with the following features.

15. The connection module according to claim 14, wherein the frame comprises a plurality of openings arranged parallel to each other, and one of the adapters is housed in each of the plurality of openings by floating mounting.

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