FIELD OF THE INVENTION

The present invention relates to multiple radio frequency connectors with a plurality of co axial connections as well as methods for coupling such connectors.

5 BACKGROUND OF THE INVENTION

Multiple radio frequency connectors that allow simultaneous coupling respectively decoupling of several coaxial radio frequency contacts is critical due to the require ments for a save mechanical and electrical coupling of each individual coaxial con nector, taking into account tolerances and misalignment. According to the state ofo the art, rigid mechanical systems of very high stiffness are used in combination with extremely small tolerances in order to address these issues.

It is an overall objective of the present invention to improve the situation regarding the coupling of multiple coaxial radio frequency connectors. Favorably, a radio fre quency connector allows for considerable tolerances and misalignment and is cost-5 efficient in manufacture. Further, the resulting coupling is stable with respect to passive intermodulation ( PI M ) . Further, a compact design is highly desirable. WO201 1088902A1 of the applicant discloses single coaxial board-to board con nectors with a movable intermediate element to compensate for tolerances and misalignment.

SUMMARY OF THE INVENTION The overall objective is solved by the subject matter of the independent claims. Exemplary and favourable embodiments are defined by the dependent claims as well as the disclosure as a whole.

A radio frequency connector may comprise a first connector part and a second connector part, the first connector part and the second connector part being configured for releasable coupling. The first connector part and the second connector part generally form a plug- socket combination.

The first connector part may comprise a first connector part body and the second con nector part may comprise comprises a second connector part body. Further, the first con nector part may comprise a plurality of coaxial first contact inserts and the second con- nector part comprises a corresponding plurality of associated coaxial second contact in serts. Each first contact insert may comprise a first outer conductor, a first inner conductor and a first spacer, the first spacer being radially arranged between the first outer conductor and the first inner conductor. Similarly, each second contact insert may comprise a second outer conductor, a second inner conductor and a second spacer, the second spacer being radially arranged between the second outer conductor and the second inner conductor. Each of the first contact inserts may be arranged and permanently fixed in a corresponding opening, e. g. bore, of the first connector part body. Similarly, each of the second contact inserts may be arranged and permanently fixed in a corresponding opening, e. g. bore, of the second connector part body. Further, each of the first contact inserts and second con tact inserts extends along a longitudinal axis that is, apart from tolerances, parallel with a longitudinal connector axis.

The radio freguency connector may further comprise a plurality of coaxial intermediate contact elements, with each intermediate contact element being associated with a first contact insert and the corresponding second contact insert. Each intermediate contact el ement may comprise an intermediate outer conductor, an intermediate inner conductor and an intermediate spacer, the intermediate spacer being radially arranged between the intermediate outer conductor and the intermediate inner conductor.

The number of first contact inserts, second contact inserts and intermediate contact inserts is generally identical and corresponds to the number of radio freguency connections. In typical embodiments, the number of high freguency connections may, for example, be 4, 5, 8, or 9.

Generally, each first and second outer conductor, inner conductor and spacer are elon gated elements in coaxial arrangement. The same applies for each intermediate contact element with intermediate outer conductor, intermediate inner conductor and intermedi ate spacer. All contact elements are made from radio freguency suited conductive material, while all spacer elements are made from insulating, in particular dielectric material. Each intermediate contact element may be arranged to axially overlap with the associated first contact insert and the associated second contact insert in an engaged configuration of the first connector part and the second connector part, such that each intermediate outer conductor electrically connects the associated first outer conductor with the associ- ated second outer conductor and each intermediate inner conductor separately electrically connects the associated first inner conductor with the associated second inner conductor. The intermediate contact elements are accordingly electrically arranged between the first contact inserts and corresponding second contact inserts.

Further, each intermediate contact element may be arranged in swiveling coupling with the associated first contact insert or second contact insert in a swiveling area to allow swiv eling of the intermediate contact element when coupling the first connector part and the second connector part by a coupling movement along a longitudinal axis. The swiveling area is circumferentially surrounded by the first connector part body or second connector part body, respectively. That is, the swiveling area is located within the first or second con- nector part body. While each first contact insert and corresponding second contact insert are ideally axially, this is generally not the case due to tolerances and limited stiffness. The swiveling of the intermediate contact elements during the coupling individually bridges and compensates for the in particular radial displacement that may be present between indi vidual pairs of first contact inserts and second contact inserts. Such displacement or misa- lignment may be different for each pair of first and second contact insert. Swiveling of the intermediate contact elements is favourable possible in all directions. Further, swiveling is separate and individual for each intermediate contact element. Swiveling of the intermedi ate contact elements is particularly enabled in the uncoupled state of the first connector part and second connector part. Upon coupling, each intermediate connector part moves. by way of the contact with the other of the first and second contact insert, into an orienta tion where it compensates misalignment between the first contact insert and second con tact insert. In the fully coupled state, freedom of the intermediate contact elements to swivel is cancelled. A method for releasably coupling the first connector part and a second connector part of a radio freguency connector may include moving the first connector part and the second connector part towards each other with a coupling movement along a longitudinal axis, thereby establishing a coupling between the first connector part and the second connector part, wherein the establishing of the coupling includes individually swiveling each interme- diate contact element into an orientation where it compensates a misalignment between the first contact insert and second contact insert.

In an embodiment, at least one of the first connector part or the second connector part (3 ) is designed for mounting on a printed circuit board. For this purpose, a connector part may have a generally flat base surface and the corresponding inner and outer conductor may have a corresponding soldering surface.

Further in an embodiment, either the first contact inserts or the second contact inserts are each designed for electrically connecting with an associated coaxial cable. For such em bodiment, either the first or second connector part is accordingly designed to be attached to a cable, the cable again comprising a plurality of individual coaxial cables. In the context of such embodiment, the present invention is particularly suited since each conductor of the cables exerts mechanical forces and/or torgues on the connected contact elements, thereby causing misalignment. In an embodiment, each intermediate contact element is permanently coupled to either the associated first contact insert or the associated second contact insert. Preferably, each intermediate contact element comprises a limited axial clearance in an unengaged config uration of the first connector part and second connector part. In such embodiment, the intermediate contact elements form an integral part of the first or second connector part. When separating the first and second connector part, the intermediate contact elements will accordingly remain coupled with the corresponding connector part. A permanent cou pling with limited axial clearance or movability of the intermediate contact elements may be favourable achieved via corresponding engaging structures, in particular of either the first or second spacer and the intermediate spacer in the swiveling area.

In an embodiment, each intermediate inner conductor comprises an elongated intermedi ate inner conductor body and radial spring projections at axially opposing ends of the in termediate inner conductor body. In an engaged state of the first connector part and the second connector part, one of the radial spring projections is arranged in an axial receiving cavity of the first inner conductor and contacts a circumferential inner surface thereof. The other radial spring projection is arranged in an axial receiving of the second inner conductor and contacts a circumferential inner surface thereof. The contact is favourable a sliding contact that allows axial and angular movement of the intermediate inner contact conduc tor relative to the first and second inner conductor. In an embodiment, the spring projec- tions may be approximately ball-shaped and the spring effect may be achieved by radial slits in the opposing end sections of the intermediate inner conductors. Via the flexibility, the spring projections are biased radially outwards towards the circumferential inner sur face of the first and second inner conductor, respectively. In an embodiment, each intermediate outer conductor comprises an elongated intermedi ate outer conductor body and radial spring projections at axially opposing ends of the in termediate outer conductor body. In an engaged state of the first connector part and the seconds connector part, one of the radial spring projections is arranged radially inside the first outer conductor and contacts a circumferential inner wall thereof. The other of the radial spring projections is arranged radially inside the second outer conductor and con tacts circumferential inner wall thereof. The contact is favourable a sliding contact that al lows axial and angular movement of the intermediate outer conductor relative to the first and second outer conductor. In an embodiment, the spring projections may be achieved by providing a circumferential protrusion at each axial end of an intermediate outer con ductor and further providing a number of radial slits in the opposing end sections of the intermediate outer conductors. Thereby, a number radially elastic thongs is established around the circumference of the intermediate outer conductor that form, in combination, a segmented radial spring projection. Via the flexibility, the spring projections are biased radially outwards towards the circumferential inner surface of the first and second outer conductor, respectively.

In an embodiment, for each intermediate contact element, the intermediate inner conduc tor is permanently connected to the associated intermediate spacer by way of positive lock ing and /or frictional locking and the intermediate spacer is permanently connected to the associated intermediate outer conductor by way of positive locking and/or force locking. For such embodiment, each intermediate contact element is a compact and generally rigid coaxial conductor element that may move and in particular swivel relative to further com ponents only as a whole. BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows a radio frequency connector with a first connector part and a second connector part in accordance with the present invention;

Fig. 2 shows a coaxial first contact insert; Fig. 3 shows a coaxial second contact insert with a coaxial intermediate contact ele ment;

Fig. 4 illustrates the coupling of the first connector part and the second connector part for the connector of Fig. 1 ;

Fig. 5 shows a first contact insert with a corresponding second contact insert and in- termediate contact element in a coupled state;

Fig. 6 shows a variation of the radio frequency connector in a partially sliced view.

DESCRIPTION OF THE EMBODIMENTS

Figure 1 shows an embodiment of a radio frequency connector 1 in a schematic perspec tive and partial sectional view. The connector 1 comprises a first connector part 2 and a second connector part 3 that are shown in an uncoupled state and spaced apart from each other, but in relative orientation that corresponds to the orientation for coupling. Coupling is achieved by moving the first connector part 2 relative to the second connector part 3 in a linear movement as indicated by arrow D, while it is to be understood that only the rela- tive movement is decisive. Figure 4 shows the first connector part 2 and the second con nector part 3 spaced apart and further tilted with respect to each other for clarity reasons. Figure 6 shows a variation of the radio frequency connector 1 in a similar view.

The first connector part comprises a first connector part body 201 and the second con- nector part 3 comprises a second connector part body 301 , both of which are generally made from insulating materials. Either or both of the first connector part body 201 and the second connector part body 301 may be made of multi single components for manufac turing and assembly purposes. In this example, the first connector part body 201 is made from stacked elements (not individually referenced) that are connected via screws 203. In the shown embodiment, the second connector part body 301 comprises a circumferen tial skirt 303 and a recessed front 302 surface from which a plurality of intermediate con tact elements 40 project, while the associated second contact inserts are arranged within the second connector part body 301 . The first connector part body 201 of the first con nector part 2 comprises a plurality of first contact inserts 20 that in this embodiment do not project beyond a front surface 202 of the first connector part body 201 but are flush with or sands back behind front surface 202. A chamfer (not referenced ) is provided in the front surface 202 around each first contact insert to guide associated intermediate contact element during the coupling respectively mating. In a coupled state, the front surfaces 202, 302 face towards each other and about each other or with some clearance. Further in this embodiment, the first connector part 2 comprises an optional circumferential seal ing 204 that seals, in a connected stated, against an inner circumferential surface (not referenced ) of skirt 303. Further in the shown embodiment, each first contact insert 20 is designed for electrically connecting with a corresponding coaxial cable 5. The second connector part 3 is designed for mounting on a printed circuit board by way of surface mounted technology (SMT). As schematically shown in Figure 5, each coaxial cable 5 comprises a jacket 51 , an outer cable conductor 52 that is electrically connected with the first outer conductor 21 , an interme diate insulating dielectric 53 , and an inner cable conductor 54 that is electrically connected with the first inner conductor 22 of a first contact insert 20 (see Figure 5).

It is noted that the intermediate contact elements 40 may alternatively also be arranged at the first connector part 2, or the intermediate contact elements may be partly arranged at the first connector part 2 and partly at the second connector part 3.

Figure 2 shows the design of a first contact insert 20 in more detail in a perspective sec tional view. The first contact insert 20 comprises pin-shaped first outer conductor 21 and tubular first inner conductor 22, with tubular first spacer 23 being radially arranged be tween them, thereby mechanically coupling and electrically insulating them from each other. The first spacer 23 is mounted inside the first outer conductor 21 by way of positive locking and/or force locking, with the first outer conductor 21 exemplarily comprising a locking structure 21 a on its circumferential inner surface and the first spacer 23 comprising a corresponding locking structure 23a on its circumferential outer surface. Similarly, first inner conductor 22 is mounted inside the first spacer 23 by way of positive locking and /or force locking, with the first inner conductor 22 exemplarily comprising a locking structure 22b on its circumferential outer surface and the first spacer 23 comprising a corresponding locking structure 23 b on its circumferential inner surface. Further exemplarily, the first spacer 23 comprises an outwards directed radial protrusion 23c that abuts an inwards di rected radial shoulder 21 c of the first outer conductor 21 , thereby defining an axial stop and strain relief. Each first contact insert 20 is arranged in a corresponding axial opening of the first connector part body 201 . The arrangement of the first outer conductor 21 , the first inner conductor 23 and the first spacer 23 is coaxial.

Figure 3 shows the design of a second contact insert 30 and an associated intermediate contact element 40 in more detail in a perspective sectional view, while Figure 5 shows the cooperation with the associated first contact insert 20 in the coupled state in a per spective sectional view. The second contact insert 30 comprises tubular second outer con ductor 31 and an inner conductor 32 with tubular second spacer 33 being radially ar ranged between them, thereby mechanically coupling and electrically insulating them from each other. The arrangement of the second outer conductor 31 , the second inner conduc tor 32 and the second spacer 33 is coaxial.

A the bottom side, the second outer conductor 31 and the second inner conductor 32 comprise soldering structures 31 d, 32d, respectively. The second inner conductor 32 is mounted inside the second spacer 33 by way of force locking and/or positive locking, e. g. with a press fit. The second contact insert 30 and part of the intermediate contact ele ment 40 are arranged in a bore 301 a of the second connector part body 301 .

The intermediate contact element 40 comprises tubular intermediate outer conductor 41 and intermediate inner conductor 42, with tubular intermediate spacer 43 radially ar ranged between them, thereby mechanically coupling and electrically insulating them from each other. A the bottom side the second outer conductor 31 and the second inner con ductor 32 comprise soldering structures 31 d, 32d, respectively. The intermediate inner conductor is in this example substantially pin-shaped and substantially solid. The interme diate inner conductor 42 comprises an elongated body 421 with approximately ball- shaped radial spring projections 422a, 422b at both axial ends. The intermediate inner conductor 42 is mounted and fixed in intermediate spacer 43 by way of a waist section 42a of its body 421 that engages with a radial inward protrusion 43a of intermediate spacer 43. Further intermediate spacer 43 is mounted inside intermediate outer conductor 41 by way of force locking and/or positive locking, e. g. with a press fit.

One of the end sections of the intermediate inner conductor 42 carrying the radial spring projection 422b is received in a corresponding axial receiving cavity 322 of the second inner conductor 32, such that radial spring projection 422b contacts the circumferential inner wall 321 of the receiving cavity 322. The other end section of the intermediate inner conductor 42 carrying the other radial spring projection 422a is, in a connected state of the first connector part 2 and the second connector part 3, received in a corresponding axial receiving cavity 222 of the first inner conductor 22, such that radial spring projection 422a contacts the circumferential inner wall 221 of the receiving cavity 222.

The intermediate outer conductor 41 comprises an elongated intermediate outer conduc- tor body 41 1 with radial spring projections 41 2a, 41 2b at both axial ends. At best seen in Fig. 3, the intermediate outer conductor body 41 1 comprises for this purpose a number of slits in its axial end sections, thereby producing a number of radially elastic segments around the circumference of the intermediate outer conductor that form, in combination a radial spring projection 41 2a, 41 2b. The radial spring projections 41 2a, 41 2b are ac- cordingly circumferentially segmented.

One of the end sections of the intermediate outer conductor 41 with a radial spring pro jection 41 2b is received radially inside the second outer conductor 31 and the segments of the radial spring projection 41 2b contact the circumferential inner wall 31 1 thereof. The other end section of the intermediate outer conductor 42 with the other radial spring pro jection 41 2a is, in a connected state of the first connector part 2 and the second connector part 3, received radially inside the first outer conductor 21 and the segments of the radial spring projection 41 2a contact a circumferential inner wall 21 1 thereof. The first spacer 33 further comprises a circumferential protrusion 33b that engages a cir cumferential inner recess 43b of the intermediate spacer 43. The circumferential protru sion 33 b and the circumferential recess 43b are in an axial area of the first spacer 33 and the intermediate spacer 43 that lies within the second connector part body 301 . Further the circumferential recess 43b is axially longer as compared to the circumferential protru- sion 33b, thereby providing for a limited axial clearance of the intermediate spacer 43. Also, the contact of the radial spring projection 422b of the intermediate inner conductor 42 with the circumferential inner wall 321 of the receiving cavity 322 as well as the contact of the radial spring projection 41 2b of the intermediate outer conductor 41 with the cir cumferential inner wall 31 1 of the second outer conductor 31 lies within the second con- nector part body 301 . From Fig. 3 and Fig. 5 it can further be seen that the second contact element 30 is arranged within the second connector part body 301 , while the intermediate contact element 40 is partly arranged within the second connector part body 301 , but projects beyond the front surface 302 of the second connector part body 301 .

Further it can be seen from Fig. 3 that a radial clearance is present between the circumfer- ential walls of the bore 301 a of the second connector part body 301 and the intermediate outer conductor 41 as radially outmost element of the intermediate contact element 40. In conseguence, the intermediate contact element 40 is enabled to swivel respectively tilt as a whole with respect to the second contact insert 30. When swiveling, the radial spring projection 41 2b of the intermediate outer conductor 41 slides on the circumferential inner wall 3 1 1 of the second outer conductor 31 and the radial spring projection 422b of the intermediate inner conductor 42 slides on circumferential inner wall 321 of receiving cavity 322, while maintaining electrical and mechanical contact.

When coupling the first connector part 2 and the second connector part 3, the chamfers around the first contact inserts 20 in the front surface 202 of the first connector part 2 will first come into contact with the associated radial spring projections 41 2a, thereby guiding the intermediate contact elements 40.

The variation of the radio freguency connector 1 according to Figure 6 in principle corre sponds to the variation shown in Figure 1 to Figure 5. It comprises a first connector part 2 and a second connector part 3 being configured for releasable coupling. The first and the second connector part 2, 3 are shown separated from each other. Mating of the two con nector parts 2, 3 is schematically indicated by dotted lines. The first connector part 2 com prises a first connector part body 201 and the second connector part 3 comprises a second connector part body 301 . The first connector part 2 comprises a plurality of coaxial first contact inserts 20 and the second connector part 3 comprises a corresponding plurality of associated coaxial second contact inserts 30. As visible in the Figure 1 through Figure 5 and described herein above, each first contact insert 20 comprises a first outer conductor 21 , a first inner conductor 22 and a first spacer 23. The first spacer 23 being radially ar ranged between the first outer conductor 21 and the first inner conductor 22. Each second contact insert 30 comprises a second outer conductor 31 , a second inner conductor 32 and a second spacer 33, the second spacer 33 being radially arranged between the second outer conductor 31 and the second inner conductor 32. The radio freguency connector 1 further comprises a plurality of coaxial intermediate contact elements 40 as described above, with each intermediate contact element (when engaged) being associated with a first contact insert 20 and the corresponding second contact insert 30. Each intermediate contact element 40 is arranged to axially overlap with the associated first contact insert 20 and the associated second contact insert 30 in an engaged configuration of the first con nector part 2 and the second connector part 3, such that each intermediate outer conduc- tor 41 electrically connects the associated first outer conductor 21 with the associated sec ond outer conductor 31 . Each intermediate inner conductor 42 electrically connects the associated first inner conductor 22 with the associated second inner conductor 32. Each intermediate contact element 40 is arranged in swiveling coupling with the associated first contact insert 20 or second contact insert 30 in a swiveling area to allow swiveling of the intermediate contact element 40 when coupling the first connector part 2 and the second connector part 3 by a coupling movement along a longitudinal axis. The swiveling area can be circumferentially surrounded by the first connector part body 201 or second connector part body 301 , respectively. The first connector part body 201 and the second connector part body 301 of the shown variation are both cable based, i.e. interconnected to the co- axial cables 5. In a mated position they are lockable with respect to each other by a locking screw 304 and a locking thread 205. The first and the second contact inserts 20, 30 are arranged around the locking screw 304, respectively the locking thread 205. In the shown variation, the locking screw 304 is accessible from the side.

LIST OF DESIGNATIONS

1 Radio Frequency ( RF) connector

2 First connector part

5 201 First connector part body

202 Front surface (of first connector part body 201 )

203 Screw

204 Sealing

205 Locking thread

0

3 Second connector part

301 Second connector part body

301 a Bore (of second connector part body 301 )

302 Front surface (of second connector part body 301 )5 303 Skirt

304 Locking screw

20 First contact insert

21 First outer conductor

0 21 a Locking structure (of first outer conductor 21 )

21 c Radial shoulder (of first outer conductor 21 )

21 1 Circumferential inner wall (of first outer conductor 21 )

22 First inner conductor

22b Locking structure (of first inner conductor 22)5 221 Circumferential inner wall (of receiving cavity 222) 222 Receiving cavity (of first inner conductor 22)

23 First spacer

23a Locking structure (of first spacer 23 )

23b Locking structure (of first spacer 23 )

5 23c Radial protrusion (of first spacer 23 )

30 Second contact insert

31 Second outer conductor

31 d Soldering structure (of second outer conductor 3 1 )

0 32 Second inner conductor

32d Soldering structure (of second inner conductor 23 )

33 Second spacer

33b Circumferential protrusion (of second spacer 33 )

31 1 Circumferential inner wall (of second outer conductor 31 )

5 321 Circumferential inner wall (of receiving cavity 322)

322 Receiving cavity (of second inner conductor 32)

40 Intermediate contact element

41 Intermediate outer conductor

0 41 1 Intermediate outer conductor body

41 2a, 41 2b Radial spring projections (of intermediate outer conductor 41 )

42 Intermediate inner conductor

42a Waist section (of intermediate inner conductor)

421 Intermediate inner conductor body

5 422a, 422b Radial spring projections (of intermediate inner conductor 42)

43 Intermediate spacer 43a Circumferential protrusion (of intermediate spacer 43 ) 43b Circumferential recess (of intermediate spacer 43 )

5 Coaxial cable

51 Jacket

52 Outer cable conductor

53 Dielectric

54 Inner cable conductor C Clearance

D Direction for coupling first and second connector part.