Patent Application
20180138632
The present invention relates to a female connector, of the jack type, for a 4.3-10 coaxial connection system, intended in particular to transmit radio frequency RF signals.
The applications particularly targeted by the invention are the connection of telecommunication equipment such as base transceiver stations BTS, RRU/RRH (remote radio unit/remote radio head) units and distributed antenna system for the wireless communications market.
The invention more particularly aims to propose a solution in order to avoid a destructive connection between a male connector of a connection system, designed under the series 4.1-9.5 standard designation, hereinafter a 4.1-9.5 male connector, and a female connector of a connection system, designed under the series 4.3-10 standard designation, hereinafter a 4.3-10 female connector.
The market and the prior art already feature power connectors of coaxial type for low passive intermodulation and dedicated to the telecommunications sector for cellular radio telephony infrastructures.
The trend in this market is to minimize the generation of passive intermodulation products. This is because, although the passive components, such as coaxial connectors and RF loads, 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 non-linear generators of unwanted modulation of the RF signals, which can lead to a distortion of the signals output from said components.
Thus, the connectors manufacturers, and in particular the applicant, have already developed, from proven coaxial connectors, connectors with high RF performance levels, notably with low intermodulation levels, such as those marketed under the series 4.1-9.5 and 4.3-10 designations which are IEC standards.
More particularly, the RF coaxial connection system of the 4.1-9.5 type is a standard under the reference IEC 60169-11 Ed. 1.0 (1977), which defines an inner diameter of the outer conductor (peripheral contact) of a 9.5 mm (0.374 inch) value with a characteristic impedance of 50 ohms and with a screw coupling as a locking device for mechanical locking the plug to the jack when they are in mutual connection configuration.
The RF coaxial connection system of the 4.3-10 type is a standard project under the reference IEC 61169-54:2016, which defines an inner diameter of the outer conductor (peripheral contact) of a 10 mm (0.394 inch) value with a nominal characteristic impedance of 50 ohms.
The jack 3 comprises a central contact 30 and a peripheral contact 31 arranged at the periphery of the central contact, forming a ground contact.
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. For better contact between the peripheral contact 21 of the plug 2 and the slotted peripheral contact 31 of the jack 3, the slotted peripheral contact 31 is horn shaped as a petal 310 and can withstand the elastic deformation.
In order to mechanically lock the mutual connection between plug and jack, a locking nut 22 is provided, to be screwed on the threads 32, around both the plug and the jack.
In this connection system 1, the electrical and mechanical functions can be separated, and electrical performances shall not be depended on the coupling torque, such that the connection has low intermodulation even mated with a small torque applied, typically on the order of 1 N.m. This allows the operator to mate the connection system conveniently.
The jack 5 comprises a central contact 50 and a peripheral contact 51 arranged at the periphery of the central contact, forming a ground contact.
The plug 6 itself comprises a central contact 60 and a peripheral contact 61 arranged at the periphery of the central contact, forming a ground contact.
In order to mechanically lock the mutual connection between plug and jack, a locking nut 62 is provided, to be screwed on the threads 52, around both the plug and the jack.
In this connection system 4, a low intermodulation can be achieved only if a high fastening torque is applied, typically on the order of 10 N.m.
A 4.1-9.5 connection system 4 and a 4.3-10 connection system 1 are dedicated to the same applications, notably in the field of telecommunications as mentioned above and may be found simultaneously on the same equipment
The threads 22, 32 and 52, 62 to achieve the locking in both 4.1-9.5 and 4.3-10 connection systems 1; 4 are identical, of the M20×1 type.
Moreover, the external size of the connectors 2,3 is the same than for connectors 5,6, and the outer shape of the plug 2 of the 4.3-10 system 1 is similar than the plug 6 of the 4.1-9.5 system 4.
Due to these identical sizes and similar shapes, an operator in charge of making the connection can easily confuse these two connections systems 1 and 4, when manipulating them.
If such an error on the types of connection system arrives, damages occur on the connectors, as shown on
When an operator accidentally makes a mismating between a 4.1-9.5 plug 6 and a 4.3-10 jack 3, the peripheral contact 61 with has a chamfer 63 at the front end of the interface of the plug 6 can easily go into the slotted peripheral contact 31, after tighten the coupling nut 62 with thread 32 even manually. Then, it can occur a plastic deformation of the petals 310 of the peripheral contact 31, as shown in
Additionally, it is possible that during a connexion between a 4.3-10 plug and a 4.3-10 jack, the 4.3-10 plug 2 has a big tilting angle of 15˜25°, due to the short guidance during the connexion operation, such that the petals 310 of the slotted peripheral contact 31 of the 4.3-10 jack 3 may have a big deformation as shown on
Because no mechanical protection is provided, as described above it is possible to permanently deform in a plastic state, the slotted peripheral contact 31, if the material is not enough elastic in order to resist to additional lateral forces, for example, which can he brought from the gravity of the mass of the cable assembly which is linked to the jack 3.
In the same way, such an important deformation may occur during an unmating operation as well. Such deformations would drastically reduce the intermodulation performance of the connexion.
There is therefore a need to further improve the RF coaxial connection systems of the 4.3-10 type, notably in order to prevent any mismating between a 4.1-9.5 male connector and a 4.3-10 female connector.
Additionally, there is a need to increase the robustness of a 4.3-10 connexion, and to achieve a mechanical protection for the slotted peripheral contact of a 4.3-10 female connector during the mating and unmating operations.
The invention aims to address all or some of this (these) need(s).
The subject of the invention is thus a mechanical protective ring, made of a dielectric material, with an external diameter intended to cooperate with the inner diameter of a ground contact of a 4.3-10 female connector, and with an inner diameter adapted such that in case of a mismating of a ground contact of a 4.1-9.5 plug connector into said ring, the front face of ring comes into abutment with said ground contact of a 4.1-9.5 plug connector.
Thus, the invention mainly consists in the use of a supplemental piece, inserted between the center contact and the outer contact which prevents any introduction of a male connector which is not dedicated.
In other words, the protective ring according to the invention avoids the undesired deformation (damage) of the elastic slotted peripheral contact.
A female connector with a protective ring according to the invention meets the requirement of a jack under the series 4.3-10 designation.
A 4.3-10 female connector according to the invention has the following advantages:
According to an advantageous embodiment, the ring is made of a cylindrical piece with longitudinal stiffening ribs, spaced one from the others, extending parallel to the axis of the cylinder.
Preferably, the stiffening ribs extend along the whole length of the ring.
Preferably, the ring comprises peripheral cutouts which are located at the rear end of the ring facing the bottom of the peripheral contact.
The invention concerns also, under another aspect, a female connector of the 4.3-10 jack type for a coaxial connection system, intended to transmit radio frequency RF signals, of longitudinal axis X, the female connector comprising:
According to an advantageous variant, the mechanical protective ring has at least one protrusion on its periphery which is inserted in a slot of the peripheral slotted contact while being in abutment with the bottom of said slot, said ring having at least one surface defining an exterior diameter in interference fit with a diameter of an internal surface of the peripheral contact.
Preferably, the front end of the ring is aligned in the plane (P) defined by the front end of the elastic portions of the peripheral contact.
At last, the invention concerns a coaxial connection system, marketed under the series 4.3-10 standard designation, comprising a male connector of the type plug and a female connector of the jack type such as described above.
Other advantages and features of the invention will become more apparent on reading the detailed description of exemplary implementations of the invention, given as illustrative and non-limiting examples with reference to the following figures in which:
These
In the interests of clarity, the same references designating the same elements of a connection system according to the prior art and of a 4.3-10 connection system according to the invention are used for all the
According to the invention, it is provided a protective ring 7 intended to be inserted and mechanically retained in a 4.3-10 jack
As shown an
The piece 7 is made of a molded plastic material, such as POM or PBT, which has a relatively high mechanical rigidity compare to PTFE, and a low dielectric constant. Moreover, molded plastic material minimizes the cost added to an existing 4.3-10 connection system.
The ring comprises several protrusions 72 distributed regularly on the cylindrical surface 70. The outer diameter of the cylindrical surface 70 of the ring 7 is slightly smaller than the diameter of internal surface of the slotted peripheral contact 31 under working condition (when a 4.3-10 standard plug mated with a 4.3-10 jack), such that there is no supplemental mechanical constraint when a 4.3-10 standard plug 2 is mated with a 4.3-10 jack 3 with a ring 7 according to the invention.
When there are additional lateral forces during an unmating operation, the ring 7 protects the slotted peripheral contact 31 by the cylindrical surface 70, due to its great rigidity material and stiffening ribs, in order to avoid any deformation of the petals 310 of the peripheral contact 31.
As explained hereafter, each protrusion 72 has a width which is slightly smaller than the width of a slot 311 which separates two adjacent petals 310 of a peripheral contact 31 of a female connector (jack) 3.
Inside the ring 7, several stiffening ribs 73 are spaced one from the others, extending parallel to the axis of the cylinder, along the whole length of the ring 7. The thickness of the stiffening ribs is comprised between 0.1 and 0.5 mm.
It must be understood that these dimensions are optimized with a plain material and that they are not restrictive. The main feature to he respected is the mechanical rigidity of the piece according to the invention. A foam or honeycomb structures for example may be used as well with various associated thickness. And the design of the ring has to be optimized with the global dielectric constant and the requested RF performances.
At the rear end of the ring 7, there are some surfaces 74, two adjacent surfaces 74 being separated by a cutout 75. The diameter defined by the surfaces 74 is the biggest diameter of the ring 7, except for the protrusions 72.
The mounting of the protective ring 7 in a 4.3-10 known female connector is now described by reference to
Firstly, the ring 7 is brought in front of and centered with the 4.3-10 jack 3 with the rear end, i.e. the surfaces 74 and the cutouts 75 facing the space between the center contact 30 and the peripheral contact 31.
The protrusions 72 are aligned individually to the direction of a slot 311 of the slotted peripheral contact 31, such that each protrusion 72 can be inserted easily into a corresponding slot 311 (
Then, the ring 7 is pushed into the 4.3-10 jack 3, being guided by the sliding of the protrusions 72 into the slots 311 (
The ring 7 is pushed until that its rear end, i.e. the ends 720 of the protrusions 72 are in abutment against the bottom 33 of the slots 311 of the slotted peripheral contact 31 (
While attaining this abutment, it occurs an interference fit between the surfaces 74 of the ring 7 and the internal surface of outer contact 31. This interference fit allows the mechanical retention of the ring 7 into the 4.3-10 jack 3. Typically, the tolerance of the interference fit between the ring 7 and the peripheral contact is at least 0.02 mm.
In the mounted configuration, the front end 71 of the ring 7 is aligned with the front end of the petals 310 of the peripheral contact 31 in the same plane P. Of course, due to the tolerances, it has to understood that the expression “same plane” has to understood as in the same plane, to within the tolerances.
The cutouts 75, the thin-walled structure 70 and a low dielectric constant of material allows the ring 7 to minimize its influence on the RF electrical performance of the connection system 1. The typical thickness of the cylindrical piece of the ring 7 is between 0.3 to 0.8 mm. Due to very slight influence on the RF electrical performances and no influence for intermodulation, the protective ring can be directly inserted and maintained in an existing 4.3-10 female connector with no change for the structure and dimensions.
There may be a possible tilting angle between 4.3-10 plug and 4.3-10 jack due to the short guidance because there are additional lateral forces during an unmating operation. The ring 7 protects the slotted peripheral contact 31 by the cylindrical surface 70, due to its great rigid material and with internal stiffening ribs of ring, in order to avoid the worse intermodulation level or failure from any undesired deformation of the petals 310 of the peripheral contact 31.
If an operator would mistakenly try to mate a 4.1-9.5 plug 6 with a 4.3-10 jack 3 including a protective ring 7 according to the invention, then this latter will avoid it by creating a physical barrier.
This situation is shown on
The ring 7 thus avoids the risk of accidental damages of the peripheral contact 31 due to an undesired intrusion of a 4.1-9.5 plug 6 by mismating.
Other variants and enhancements can be provided without in any way departing from the framework of the invention.
The expression “comprising a” should be understood to be synonymous with “comprising at least one”, unless otherwise specified.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2016/105519 | 11/11/2016 | WO | 00 |
