WO2014026383A1

WO2014026383A1 - A coaxial power connection system, intended to transmit rf power signals

Info

Publication number: WO2014026383A1
Application number: PCT/CN2012/080313
Authority: WO
Inventors: Shan QIN; Zhenhua Yang
Original assignee: Shanghai Radiall Electronics Co., Ltd
Priority date: 2012-08-17
Filing date: 2012-08-17
Publication date: 2014-02-20
Also published as: CN104641516B; CN104641516A

Abstract

A coaxial power connection system comprises: a plug, a socket, and a bayonet-type locking device.The plug and the socket each comprises: a central contact, a ground contact. The bayonet-type locking device is suitable for mechanically locking the plug to the socket, in which the bayonet locking device is suitable for providing and allowing an axial operating play to remain between ground contacts on the axis X. Once the locking is done, the connection between ground contacts is produced by the radial bearing of the ground contact against the interior of the other ground contact.The system also comprises a spring, arranged around the ground contact,and the spring is compressed by the bearing of the other ground contact when the plug is locked to the socket,then maintains compressed once the locking is done so as to keep the plug and the socket locked together with the axial operating play between ground contacts.

Description

A COAXIAL POWER CONNECTION SYSTEM, INTENDED TO TRANSMIT

RF POWER SIGNALS

Technical field

The present invention relates to a coaxial power connection system, intended in particular to transmit radio frequency RF power signals.

The applications particularly targeted by the invention are the connection of telecommunication equipment such as base transceiver stations BTS and RRU/RRH (remote radio unit/remote radio head) units for the wireless communications market.

The invention also relates generally to the connection systems in the medical domain, the industrial domain, the aeronautical or transport domain and the space domain.

The invention more particularly aims to propose a power connection system of coaxial type for which the electrical and mechanical RF performance levels are controlled and stable over time, with, in particular, a low contact resistance and a low intermodulation level. Prior art

The market and the prior art already feature power connectors of coaxial type dedicated to the telecommunications sector for cellular radio telephony infrastructures .

The trend in this market is to minimize the generation of intermodulation products. This is because, although the passive components, such as coaxial connectors and RF leads, were considered to be linear, it has been found that in reality these components were susceptible to behave as intermodulation generators, that is to say generators of unwanted modulation of the RF signals, which can lead to a distortion of the signals output from said components.

Thus, the applicant has already developed, from proven coaxial connectors, coaxial power connectors with high RF performance levels, notably with low intermodulation levels, such as those marketed under the series 7-16 or series N and 4.1/9.5 designation.

Figure 1 shows, in longitudinal cross section, a coaxial power connection system which has been marketed for more than 30 years under the series 7/16 designation and which aimed to ensure power transmission of RF signals with no real demand on the intermodulation level . As shown in Figures 1A, IB and 1C, the socket 3 comprises a central contact 30 and a peripheral contact 31 arranged at the periphery of the central contact, forming a ground contact. Furthermore, an insulator which is not represented is interposed between the central contact and the ground contact, all these elements being housed in a body 32. As illustrated in Figures 1A and IB, the central 30 and ground 31 contacts are each in the form of a slotted sleeve. In order to mechanically lock the mutual connection between plug and socket, a locking cap 4 was provided, to be screwed around both the plug and the socket.

The plug 2 itself comprises a central contact 20 and a peripheral contact 21 arranged at the periphery of the central contact, forming a ground contact. Furthermore, an insulator 23 is interposed between the central contact and the ground contact. The central 20 and ground 21 contacts of the plug are solid contacts, that is to say not slotted.

The development of the base transceiver stations BTS has necessitated the development of interconnection assemblies, in particular of coaxial connectors guaranteeing a low intermodulation level . Now, the applicant then found that a coaxial connection system with the socket 3 represented in Figures 1A, IB, 1C could not in fact guarantee a low intermodulation level.

After study, it was in fact established that the slotted form of the sleeve forming the ground contact 31 of the socket 3, and the radial contact that it induced on the plug 2, associated with the weak axial abutment contact on the longitudinal axis X did not make it possible to obtain a satisfactory intermodulation level. The tightening torque applied to the locking cap 4 was then increased to produce a strong contact in abutment, on the longitudinal axis X of the connection system, of the ground contact of the socket 3 against the ground contact of the plug 2. By convention, hereinafter, the plane P is designated as being the one defined by the longitudinal end of the petals of a pin forming a ground contact in a coaxial connector. Thus, the strong contact in abutment on the plane P generates a low intermodulation level .

At the same time, the ground contact has become not slotted. This is because the pressure applied by the slotted ground contact of the plug 2 on the socket 3 could induce, with the high tightening torque applied to the locking cap, a buckling of the petals 310 of the pin 31 forming the ground contact of the socket. Furthermore, the tightening torque applied could have a tendency to relax over time, and cause the electrical performance levels associated with the connectors to change .

So, to mitigate these drawbacks, and in particular guarantee a low intermodulation level, the applicant had to develop a coaxial-type power connector as shown in Figure 2, and still marketed to this day under the designations series 7/16, series 4.1-9.5 and series N.

This coaxial connection system 1 comprises a plug 3 intended to be mutually connected with a socket 2 for the transmission of the RF signals. The plug 3 comprises a central contact 30 and a peripheral contact 31 arranged at the periphery of the central contact, forming a ground contact. Furthermore, an insulator 33 is interposed between the central contact and the ground contact, all these elements 30, 31 being housed in the body 32. The socket 2 also comprises a central contact 20 and a peripheral contact 21 arranged at the periphery of the central contact, forming a ground contact. Furthermore, an insulator is interposed between the central contact and the ground contact, all these elements 20, 21 being housed in the body 22. The ground contacts 21, 31 of the connectors of Figure 2 are solid contacts, that is to say not slotted.

To guarantee a low intermodulation level, it was then planned to increase the tightening torque of the locking device 4 of screw/nut type. As shown in Figure 2, this device 4 consists of a nut 24 mounted free in rotation around the body 22 of the plug 2 and a screw, the threads 34 of which are produced on the periphery of the body 32 of the socket 3. Thus, by the application of a strong screwing torque on the nut 24 engaged on the threads 34 of the socket 3, the solid ground contact 31 applies pressure on the plane P against the solid ground contact 21. By reaction, a resultant pressure dependent on the tightening torque is obtained on the plane P, this pressure inducing an electrical contact between the two ground contacts 21, 31. Thus, the application of a strong screwing torque makes it possible to reduce to the minimum the contact resistance between the two ground contacts 21, 31, to tend towards an electrical continuum, that is to say as if the two ground contacts 21, 31 were of a single piece. This significantly reduces the intermodulation level in particular.

Thus, a power connection system 1 represented in Figure 2 offers high RF performance levels with, in particular, a low intermodulation level, a low reflection rate, a low loss level.

The drawback of this power connection system of Figure 2 lies essentially in the need to apply a strong screwing torque in order to guarantee a strong contact pressure between ground contacts. This strong screwing torque to be applied is also needed to reduce the risks of unscrewing linked to the effects of thermomechanical relaxation which appear in the lifecycle of the connector subject to temperature differences, vibrations, etc., which can in particular induce the unscrewing of the nut in case of insufficient torque: thus, the screwing torque is stronger than necessary in order to offer the maximum guarantee over time of the contact pressure between ground contacts and, through that, a low intermodulation level .

Thus, in a coaxial power connection system 1 according to Figure 2, it is necessary:

- to engineer robust parts supporting the application of shear forces, such as the threads 34 and the nut 24, pulling forces, such as the body 30, and compression forces, such as the ground contact 31, these forces being generated by the strong screwing torque of the nut 24 on the threads 34,

- to use a bulky torque wrench to apply a significant and controlled screwing torque, typically

30 to 35 N.m for the series 7/16.

There is therefore a need to further improve the RF power connection systems of coaxial type with low intermodulation level.

The invention aims to address all or some of these needs.

Explanation of the invention

The subject of the invention is thus a coaxial power connection system, intended to transmit radio frequency RF power signals, of longitudinal axis X, comprising :

- a first system element forming a plug and a second system element forming a socket, the plug and the socket each comprising:

• a central contact, • a peripheral contact, arranged on the periphery of the central contact, forming a ground contact ,

• an insulator interposed between the central contact and the ground contact,

- a bayonet-type locking device suitable for mechanically locking the plug to the socket when they are in mutual connection configuration.

According to the invention, one of the ground contacts is elastic and comprises a slotted sleeve, whereas the other ground contact is rigid and comprises a rigid body provided with a recess, the slotted sleeve bearing radially against the interior of the rigid body in connection configuration between plug and socket.

Also according to the invention, the bayonet locking device is suitable for providing and allowing an axial operating play (J) to remain between ground contacts on the axis X, once the locking is done, the connection between ground contacts being produced by the radial bearing of the elastic one against the interior of the rigid one .

The connection system according to the invention also comprises a spring- forming element working in compression mode, arranged around the elastic ground contact; the spring- forming element being compressed by the bearing of the rigid ground contact when the plug is locked to the socket by the locking device, then maintained compressed once the locking is done so as to keep the plug and the socket locked together with the axial operating play (J) between ground contacts.

This spring- forming element exhibits a strong stiffness and a limited travel for satisfactory system performance levels.

The expression "bayonet-type locking device" should be understood to mean a locking device that works by the cooperation of at least one pin (stud) with an opening (slot) and which can be implemented manually without there being any need to use tools to increase the locking force by hand. Such a bayonet locking device is usually known generically as a rapid locking device.

Thus, the invention mainly consists in ensuring, stably and reliably over time, the axial immobilization of the ground contacts while ensuring an axial operating play between ground contacts through a rapid locking system. In other words, the invention consists in definitely doing away with any damaging abutment at the end of ground contacts as with the coaxial connectors according to the prior art, for example those already marketed under the designations series 7- 16, N, 4.1-9.5 by the applicant.

A power connection system according to the invention exhibits high RF performance levels, with in particular a low intermodulation level, a low VSWR (voltage standing wave ratio) reflection rate, low transmission losses, a low rate of RF leaks, that are stable over time.

Unlike the power connection systems according to the prior art, such as the one shown in Figure 2, there is no need to use bulky tools. Thus, a power connection system according to the invention allows for a connection and locking between plug and socket that is faster and more reliable than according to the prior art .

As a corollary, using connection systems according to the invention for an installation on a fixing panel increases the density of the installation compared to connection systems according to the prior art as shown in Figure 2: this is because there is no longer any need to provide additional space for the placement and manipulation of a wrench. In other words, it is possible to install more power connection systems according to the invention than connection systems according to the prior art on one and the same fixing panel surface area. According to an advantageous characteristic, one of the central contacts is a rigid pin whereas the other central contact is a slotted sleeve forming a tulip contact.

According to an advantageous variant, the spring working in compression mode consists of an 0- ring seal made of compressible material. Thus, the seal produces both the fluidtightness with respect to the outside and the spring function for maintaining the locking between plug and socket with the axial operating play according to the invention between ground contacts.

Advantageously, the spring- forming element is substantially at the compressibility limit when the hard point of the locking device is reached when locking the plug to the socket, the hard point being defined as the point of operation of the locking device at which the greatest force has to be applied when locking. The force of the spring is thus optimized according to the locking to be maintained.

According to an advantageous embodiment, the bayonet type locking device comprises:

- at least one locking pin formed at the periphery of the rigid ground contact;

- a locking element, called locking cap, mounted to be at least free in rotation around the elastic ground contact, the locking cap comprising an external portion suitable for manual gripping, and an internal portion provided with at least one locking opening;

each locking pin being suitable for cooperating with a locking opening by translation and rotation of the locking cap around the rigid ground contact, so as to mechanically lock the plug to the socket simultaneously with their mutual connection.

Such a bayonet locking device is simple to produce and reliable over time. According to a variant embodiment, the internal and external portions of the locking cap are distinct parts force fitted into one another.

According to one alternative variant, the internal and external portions of the locking cap constitute one and the same part produced by overmoulding .

Preferably, the locking cap is mounted fixed in translation around the elastic ground contact.

According to an advantageous embodiment, the device also comprises an 0-ring seal arranged at the periphery of the rigid ground contact and bearing against the interior of the locking plug once the locking is done.

Preferably, for the bayonet device, there are provided three locking pins distributed at 120° relative to one another on the periphery of the rigid ground contact, and the locking cap comprises three locking openings of the same form distributed at 120° relative to one another, any of the locking pins being suitable for cooperating with any of the openings.

Preferably, the elastic ground contact is made of or coated with a material chosen from a material based on silver, a tin alloy, copper, zinc or a high- strength bronze.

A power connector which has just been described can exhibit a 3rd order intermodulation level less than -120 dBm for two RF carriers of 20 W ranging from 0 to 7.5 GHz.

Detailed description

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

- Figure 1 is a longitudinal cross-sectional view of a coaxial power connection system according to the prior art, the plug and the socket being in mutual connection and locking configuration;

- Figures 1A to 1C are views respectively in perspective, in longitudinal cross section and from the side of a socket of a coaxial power connection system according to the prior art and used in the connection system of Figure 1 ;

- Figure 2 is a longitudinal cross-sectional view of another coaxial power connection system according to the prior art, the plug and the socket being in mutual connection and locking configuration;

- Figure 3 is a longitudinal cross-sectional view of a coaxial power connection system according to the invention, the plug and the socket being in mutual connection and locking configuration;

- Figure 3A is an enlarged view of the interface of Figure 3 ;

- Figures 4A to 4C are longitudinal cross- sectional views of a coaxial power connection system according to the invention, showing the plug and the socket respectively in disconnected configuration, during connection and in mutual connection and locking configuration;

- Figures 5A to 5C are perspective views of a coaxial power connection system according to the invention, corresponding to the configurations of Figures 4A to 4C;

- Figures 6A and 6B are schematic cross- sectional views showing the positions respectively during the locking and once the locking is completed of the elements of the locking device of a coaxial power connection system according to the invention;

- Figures 7A and 7B are perspective views respectively showing a plug and a socket of a coaxial power connection system according to the invention.

Figures 1, 1A to 1C and 2 relate to two different examples of coaxial power connection systems according to the prior art. These Figures 1, 1A to 1C and 2 have already been commented on in the preamble and will not therefore be commented on further hereinbelow .

Hereinafter, the invention is described with reference to an RF line of 7/16 type and with a bayonet-type rapid locking device by way of example and illustration. However, the invention can be applied to any type of power RF line.

Figures 3 and 3A represent an example of a coaxial power connection system 1, according to the invention, the plug 2 and the socket 3 in mutual connection and locking configuration. In this configuration, the connection system 1 extends along a longitudinal axis X. This connection system 1 comprises, respectively, a plug 2, a socket 3 and a manual locking device 4 suitable for mechanically locking the plug 2 to the socket 3 when they are in mutual connection configuration (Figures 3, 3A, 4C, 5C) .

The plug 2 comprises a central contact 20, a peripheral contact 21 arranged on the periphery of the central contact. The peripheral contact 21 is elastic and forms a ground contact. An electrical insulator 23 is interposed between the central contact 20 and the ground contact 21. In the embodiments illustrated, the contact 20 is a slotted sleeve forming a tulip contact, the petals of which are mutually close together. The ground contact 21 is also a slotted sleeve. It is advantageously formed of, or coated by a coating based on, silver or an alloy of tin, copper, zinc or a high- strength bronze. The tip of the slotted sleeve 21 of the ground contact defines a plane P.

The socket 3 comprises a central contact 30, a peripheral contact 31 arranged on the periphery of the central contact. The peripheral contact 31 is rigid and forms a ground contact. As illustrated, this rigid ground contact 31 comprises a body provided with a recess. An insulator 33 is interposed between the central contact 30 and the ground contact 31. In the embodiments illustrated, the central contact 30 is a pin. The rigid ground contact 31 is in the form of a hollow cylinder with walls that are continuous, that is to say not slotted. In other words, the rigid ground contact 31 is a contact that can be qualified as solid.

According to the invention, the locking device 4 is suitable for providing and allowing an axial operating play J to remain between ground contacts 21, 31 on the axis X, once the locking is done (Figures 3, 3A, 4C) . The connection between ground contacts 21, 31 is thus produced only by the radial bearing of the elastic ground contact 21 against the interior of the recess of the rigid ground contact 31.

Thus, by virtue of the invention, there is an assurance that there is no longitudinal abutment of the ground contact 21 against the shoulder of the ground contact 31, that is to say no contact at the longitudinal end of the ground contact 21. To express it in another way, there is no contact of the plane P of the slotted sleeve 21 with the rigid ground contact 31. By engineering the radial pressure exerted by the elastic ground contact 21 against the rigid one 31 and because of the very good electrical conductivity between these ground contacts 21, 31, a low intermodulation level is guaranteed.

As an example, the axial operating play J may advantageously be between 0.05 mm and 0.6 mm.

To guarantee that the operating play is maintained over time and the radial contact between ground contacts 21, 31 is maintained over time and therefore that high RF performance levels are maintained over time with, in particular, a low intermodulation level, a spring- forming element 5, working in compression mode, is provided, arranged around the elastic ground contact 21.

In the embodiments illustrated, the spring working in compression mode consists of an 0-ring seal made of compressible material . Both the desired spring function and the tightness to fluids outside the connector 1 are thus provided. As can be better seen in Figure 3A, the O-ring seal 5 is compressed by the bearing of the body of the rigid ground contact 31 during locking by the locking device 4, then it is kept compressed once the locking is done so as to keep the plug 2 and the socket 3 locked together with the axial operating play between ground contacts.

Advantageously, the seal 5 is substantially at the compressibility limit when the hard point of the locking device 4 is reached when locking the plug to the socket, the hard point being defined as the point of operation of the locking device 4 at which the greatest force has to be applied when locking.

In the embodiments illustrated, the manual locking device 4 is a bayonet- type device. It thus comprises one or more locking pins 35, formed on the periphery of the rigid ground contact 31. This (these) locking pin(s) 35 is (are), in the examples considered, made of a single part with the ground contact 31. Preferably, three locking pins 35 are distributed at 120° relative to one another. The device 4 also comprises a locking cap 40, 41, mounted free in rotation around the elastic ground contact 21 but fixed in translation on the axis X. This cap comprises an external portion 40 suitable for manual gripping, and an internal portion 41 provided with one or more locking openings 42. Preferably, three identical openings 42 are distributed at 120° relative to one another.

As can be better seen in Figures 6A and 6B, to produce the bayonet fixing, each locking pin 35 is suitable for cooperating with a locking opening 42 that works by translation and rotation of the locking plug 40, 41 around the rigid ground contact 31, so as to mechanically lock the plug 2 to the socket 3 simultaneously with their mutual connection. An O-ring seal 6 is preferably arranged at the periphery of the rigid ground contact 31. This seal 6 bears against the interior of the locking cap 40, 41 once the locking is done (Figures 3, 3A, 4C) .

Another O-ring seal 7 is also preferably arranged between the locking cap 41 and the elastic ground contact 21 which supports it.

With the duly provided seals 5, 6, 7, a power connection system 1 according to the invention is perfectly suited to a use in an outdoor environment, even in extreme temperature and humidity conditions.

Figures 4A to 6B show the various manual steps of mutual connection and locking between the plug 2 and the socket 3 in a power connection system 1 according to the invention, with a bayonet device 4 which has just been described, the locking cap 40, 41 being assembled with the plug 2 beforehand. All these steps can be performed simply by gripping the locking cap 4 in one hand.

Figures 4A and 5A illustrate the placing of the plug 2 and the socket 3 facing one another with alignment on the axis X.

Figures 4B and 5B illustrate the start of the connection and the locking between plug 2 and socket 3. In this step, the locking cap 40 is made to slide over the rigid ground contact 31. In this step, the elastic ground contact 21 bears radially against the interior of the recess of the rigid ground contact 31, the central contacts 20, 30 themselves being apart from one another. Simultaneously, each locking pin 35 begins to penetrate into an opening 42.

Figures 4C and 5C illustrate the end of the connection and locking between plug 2 and socket 3. First, once the preceding step is completed, the sliding of the locking cap 4 is continued and, simultaneously, it is rotated around the axis X in order to produce the complete locking. In Figure 4C, it can be seen that, in accordance with the invention, the ground contact 21 bears only radially against the interior of the recess of the rigid ground contact 31 with an axial operating play J which is therefore gauged and kept constant over time by the locking device 4.

Figures 6A and 6B more specifically illustrate the completion of the locking by the sliding then blocking of a locking pin 35 in a locking opening 42. When the rigid ground contact 31 has compressed the compressible seal 5 to the point where the latter is at the compression limit, then each pin 35 passes the hard locking point, that is to say, the point of the opening 42 in which it slides which is the furthest away from the inlet (Figure 6A) . Once this hard point is passed by the pin 35, the seal 5, by its spring effect, holds each pin 35 in its corresponding opening (Figure 6B) , that is to say the connected configuration with the plug 2 on the socket 3.

The advantages of a coaxial power connection system 1 according to the invention, which has just been described, are numerous compared to a coaxial power connection system according to the prior art, such as the one marketed under the designation series 7/16 :

- high RF power signal transmission performance levels maintained, even increased, with in particular a low intermodulation level;

- stability over time of said high performance levels ;

- absence of the need to apply a strong tightening torque with, as a corollary, the absence of a need for a bulky and costly torque wrench;

- increased installation density on a panel: in practice, because of the rapid locking, simply by hand, there is no need to provide a greater free space dedicated to the placement and manipulation of tools such as a torque wrench. Other variants and enhancements can be provided without in any way departing from the framework of the invention .

Thus, while the invention has been described with reference to an RF line of type 7/16, it can equally be applied to any type of power RF line.

Although, in the embodiments illustrated, the external 40 and internal 41 portions of the locking cap 4 are made of distinct parts force fitted into one another, it is possible, as an alternative variant, to provide for these portions to be of a single part produced by overmoulding .

Moreover, the outer gripping portion of the locking cap 4 can be solid, that is to say without openings 42 or other openings as shown in Figures 3 to 5C, or can directly incorporate the locking openings 42 as shown in Figure 7A, the sealing of the RF line being ensured by the seal 5.

The expression "comprising a" should be understood to be synonymous with "comprising at least one", unless otherwise specified.

Claims

1. Coaxial power connection system (1), intended to transmit radio frequency RF power signals, of longitudinal axis X, comprising:

- a first system element forming a plug (2) and a second system element forming a socket (3) , the plug and the socket each comprising:

• a central contact (20; 30),

• a peripheral contact (21; 31), arranged on the periphery of the central contact, forming a ground contact ,

• an insulator (23; 33) interposed between the central contact and the ground contact,

- a bayonet-type locking device (4) suitable for mechanically locking the plug to the socket when they are in mutual connection configuration;

in which one of the ground contacts (21) is elastic and comprises a slotted sleeve, whereas the other ground contact (31) is rigid and comprises a rigid body provided with a recess, the slotted sleeve bearing radially against the interior of the rigid body in connection configuration between plug and socket;

and in which the bayonet locking device (4) is suitable for providing and allowing an axial operating play (J) to remain between ground contacts on the axis X, once the locking is done, the connection between ground contacts being produced by the radial bearing of the elastic one (21) against the interior of the rigid one (31) ; the system (1) also comprising a spring- forming element (5) working in compression mode, arranged around the elastic ground contact (21) , the spring- forming element being compressed by the bearing of the rigid ground contact (31) when the plug is locked to the socket by the locking device (4) , then maintained compressed once the locking is done so as to keep the plug and the socket locked together with the axial operating play (J) between ground contacts (21, 31) .

2. Coaxial power connection system according to Claim 1, in which the spring working in compression mode consists of an 0-ring seal made of compressible material .

3. Coaxial power connection system according to one of Claims 1 or 2 , in which the spring- forming element is substantially at the compressibility limit when the hard point of the locking device is reached when locking the plug to the socket, the hard point being defined as the point of operation of the locking device at which the greatest force has to be applied when locking.

4. Coaxial power connection system according to one of the preceding claims, the locking device (4), of bayonet type, comprising:

- at least one locking pin (35) formed at the periphery of the rigid ground contact (31) ;

- a locking element (40, 41), called locking cap, mounted to be at least free in rotation around the elastic ground contact, the locking cap comprising an external portion (40) suitable for manual gripping, and an internal portion (41) provided with at least one locking opening (42);

each locking pin (35) being suitable for cooperating with a locking opening (42) by translation and rotation of the locking plug around the rigid ground contact, so as to mechanically lock the plug to the socket simultaneously with their mutual connection.

5. Coaxial power connection system according to Claim 4, in which the locking cap is mounted fixed in translation around the elastic ground contact.

6. Coaxial power connection system according to Claim 4 or 5, also comprising an 0-ring seal (6) arranged at the periphery of the rigid ground contact (31) and bearing against the interior of the locking cap (40) once the locking is done.

7. Coaxial power connection system according to one of Claims 4 to 6 , comprising three locking pins (35) distributed at 120° relative to one another on the periphery of the rigid ground contact, and in which the locking cap comprises three locking openings (42) of the same form distributed at 120° relative to one another, any of the locking pins being suitable for cooperating with any of the openings.

8. Coaxial power connection system according to one of the preceding claims, in which the elastic ground contact (21) is made of or coated with a material chosen from a material based on silver, a tin alloy, copper, zinc or a high- strength bronze.

9. Coaxial power connection system according to any one of the preceding claims, exhibiting a 3rd order intermodulation level less than -120 dBm for two RF carriers of 20 W and ranging from 0 to 7.5 GHz.