A method of manufacturing a connector, and a connector
Description
The present invention relates to a method of manufacturing a connector and a
5 connector, and in particular a TNC connector. The connector is designed to
produce very low passive intermodulation distortion.
A TNC (threaded Neill-Concelman) connector is a well know for radio and wired
applications. A TNC connector may be a source of passive intermodulation
10 distortion. Intermodulation distortion is the unwanted modulation of signals
containing two or more different frequencies. Due to a non-linearity in the system,
each frequency component modulates the other components. A TNC connector
may not behave in a linear manner, and hence cause intermodulation, due to
junctions of dissimilar metals or junctions of metals and oxides. These junctions
I5 effectively form diodes, which are non-linear.
In many passive systems, intermodulation distortion is not usually noticeable. In a
satellite system, in particular, a telecommunications satellite, the transmit signal
power is significantly greater than the receive signal power (greater than 120 dB). It
20 is therefore important to minimise passive intermodulation distortion, otherwise
products generated by transmit carriers could fall within the receive band and cause
interference.
The present invention provides, in a first aspect, a method of manufacturing a
25 connector comprising: forming an outer connection element or inner connection
element having fingers, deforming the fingers to an angle to a longitudinal axis; and
heat treating the connection element with the fingers restrained at the angle to the
longitudinal axis such that the fingers are permanently deformed to extend at the
angle to the longitudinal axis.
30
Thus, the connector produces a very low passive intermodulation distortion.
Preferably, the method comprises initially forming the fingers extending
substantially parallel to a longitudinal axis of the connector.
Preferably, the connector is plated following the heat treating of the connector.
5
Preferably, the fingers of the inner connection element are plated while urged apart,
following the heat treating of the inner connection element.
Preferably, the fingers are plated when resiliently urged to extend substantially
10 parallel to the longitudinal axis, following the heat treating of the connector.
Preferably, the inner connection element or outer connection element are formed
from beryllium copper, and plated with silver or gold.
I5 Preferably, the silver is plated to a thickness of between 10pm and 30pm, and more
preferably 15pm + 5pm, or the gold is plated to a thickness of between 2pm and
10pm, and more preferably 5pm + 2pm.
Preferably, a surface of the fingers for contacting a co-operating connector is
20 polished to 1.2pm or better
The present invention provides, in a second aspect, a connector comprising:
an outer connection element and an inner connection element; wherein one of the
outer connection element and inner connection element comprises a plurality of
25 fingers extending at an angle relative to a longitudinal axis of the connector,
wherein the fingers are formed by heat treating when deformed and restrained at the
angle to the longitudinal axis such that the fingers are permanently deformed to
extend at the angle to the longitudinal axis.
30 Thus, the connector produces a very low passive intermodulation distortion.
Preferably, the fingers of the inner connection element are plated while urged apart,
following the heat treating of the inner connection element.
Preferably, the fingers are plated when resiliently urged to extend substantially
parallel to the longitudinal axis, following the heat treating of the connector.
5 Preferably, the inner connection element or outer connection element are formed
from beryllium copper, and plated with silver or gold.
Preferably, the silver is plated to a thickness of between 10pm and 30pm, and more
preferably 15pm + 5pm, or the gold is plated to a thickness of between 2pm and
10 10pm, and more preferably 5pm + 2pm, and/or a surface of the fingers for
contacting a co-operating connector is polished to 1.2pm or better.
The present invention further provides a connector comprising: an outer
connection element and an inner connection element; wherein one of the outer
15 connection element and inner connection element comprises a plurality of fingers
extending at an angle relative to a longitudinal axis of the connector.
Preferably, the connector is a plug, and the fingers form the outer connection
element and diverge at an angle relative to the longitudinal axis.
20
Preferably, each finger has an end comprising a protrusion extending radially
outwardly from the finger.
Preferably, the protrusions have an arcuate profile in a longitudinal direction of the
25 fingers.
Preferably, a distal end of the fingers diverges from the longitudinal axis by a lateral
distance of between 0.5mm and Imm, and preferably 0.7mm and/or the outer
connection element comprises twelve fingers arranged in an annulus.
30
Preferably, the connector is a socket, and the fingers form the inner connection
element and converge at an angle relative to the longitudinal axis.
Preferably, a distal end of the fingers diverges from the longitudinal axis by a lateral
distance of between O.lmm and 0.3mm, and preferably between 0.17mm and
0.22mm, and/or the inner connection element comprises four fingers.
5 Preferably, the connector is a TNC connector and comprises a threaded portion to
mate with a threaded portion of a co-operating TNC connector.
Preferably, the fingers are formed extending parallel to the longitudinal axis, and
deformed during manufacture to the angle to the longitudinal axis
10
Preferably, the inner connection element and outer connection element are plated
with silver, and preferably, the silver plate has a thickness of 15pm + 5pm.
Preferably, the inner connection element and outer connection element are formed
I5 from beryllium copper.
The present invention further provides a pair of connectors comprising a plug as
claimed or described, and a socket as claimed or described.
20 An embodiment of the present invention will now be described, by way of example
only, with respect to the following drawings, in which:
Figure 1 is a side elevation cross-section of a plug according to the present
invention;
25 Figure 2a is a side elevation cross-section of a body forming part of the plug of
Figure 1 ;
Figure 2b is a side elevation cross-section of part of the body of Figure 2a;
Figure 3 is a side elevation cross-section of a dielectric forming part of the plug of
Figure 1 ;
30 Figure 4 is a side elevation cross-section of a pin forming part of the plug of Figure
1;
Figure 5 is a side elevation cross-section of a socket according to the present
invention;
Figure 6 is a side elevation cross-section of a body forming part of the socket of
Figure 5;
Figure 7 is a side elevation cross-section of a sleeve forming part of the socket of
Figure 5;
5 Figure 8a is a side elevation cross-section of a probe forming part of the socket of
Figure 5;
Figure 8b is a front elevation view of the probe of Figure 8a; and
Figure 8c is a side elevation cross-section of part of the probe of Figure 8a, during
manufacture.
10
The present invention relates to TNC connectors, namely a plug and a socket which
are connectable together. Preferably, the plug and socket of the present invention
are used together. The plug and socket of the present invention are of standard
size, and so may be connected to a co-operating known TNC connector.
15
The connectors of the present invention allow passive intermodulation (PIM)
distortion levels of the order of -145dBm 5th order PIM at L- band frequencies (1 to
2 GHz) for two 50W carriers. This distortion compares to typical PIM distortion of
standard TNC connectors which is typically of the order of -80dBm under the same
20 conditions.
Figure 1 shows a plug 10 which is a connector according to the present invention.
The plug 10 may also be termed a plug connector or male connector. The plug 10 is
configured to connect with a co-operating socket. The plug 10 is a TNC connector
25 and comprises an elongate body 20 radially surrounding a dielectric 30. The
dielectric 30 radially surrounds a pin 40. A coupling part 50 having a threaded
section 52 is attached to the body 20. The arrangement of the plug 10 is
substantially the same as a known TNC connector. The plug 10 comprises an inner
connection element formed by the pin 40, and an outer connection element formed
30 by the body 20.
Figure 2a shows the body 20 of the plug 10. The body 20 is substantially annular.
Fingers 22 are formed at a first end of the body 20, forming the outer connection
element and configured to contact inside an outer connection element of the socket
to form an outer electrical connection. The conductive fingers 22 are defined by
slits 24 extending in a longitudinal direction. The slits 24 are preferably between
approximately 0.2mm and 0.3mm, and preferably 0.25mm and 0.275mm in width,
5 and extend between approximately 6.5mm and 7.5mm, and preferably 6.9mm and
7.1. Preferably, there are twelve fingers 22, arranged as an annulus and equally
spaced and dimensioned.
The body further comprises a cavity 26 at a second end, opposite to the first end.
lo The cavity 26 is configured to receive and securely attach to a cable.
Figure 2b shows an enlargement of a distal end of a finger 22, distal from the
remainder of the body. The finger 22 is provided with a profiled end 28. The
profiled end 28 has an enlarged cross-section relative to the remainder of the finger
I5 22. In particular, the profiled end 28 is a protrusion on a radially outer surface of
the fingers 22, and a radially inner surface of the fingers 22 is uniform along the
length of the fingers 22.
The profiled end 28 is curved in a longitudinal direction, in a symmetrical arcuate
20 curve and extends radially outwardly. The profiled ends 28 are uniform across the
width of the fingers 22. The profiled ends 28 preferably have a radius of curvature
of approximately between 0.5mm and Imm, and preferably between 0.57mm and
0.68mm, centred radially inwardly of the radially inner surface of the fingers 22. The
curve of the profiled ends 28 is preferably centred a distance less than the radius of
25 curvature from the distal end of the fingers 22, such that the surface of the profiled
ends comprises an arc extending through less than 180'. The centre of curvature is
between 0.25mm and 0.75mm from the distal end of the fingers, and preferably
between 0.45mm and 0.55mm. All of the fingers 22 are provided with such profiled
ends 28.
30
The body 20 is formed from beryllium copper. Beryllium copper has physical
characteristics which allow the fingers to be resiliently deformable, in particular, the
fingers may readily deformed and return to their original configuration. The
beryllium copper is plated with a layer of copper, preferably between lpm and 5pm,
and more preferably 2pm + lpm in thickness. A layer of silver plate is then applied
onto the copper plate. The silver plate is between 10pm and 30pm, and is
preferably 15pm + 5pm in thickness. The plating may be allowed to have a
5 maximum thickness of 50pm on internal corners. The plating materials and
thicknesses have been selected to provide optimum conductivity. Due to the skin
effect, electric current is substantially carried by the outer silver layer at microwave
frequency (e.g. 1 to 2 GHz).
lo The fingers 22 are initially formed extending substantially longitudinally and parallel
to each other, e.g. by machining, with an internal diameter of between
approximately between 6.8mm and 7.3mm, and preferably between 7.100mm and
7.122mm. After machining, the fingers 22 are then mechanically deformed to
extend at an angle to a longitudinal axis. The fingers 22 are splayed apart so that the
I5 profiled ends 28 contact an internal diameter of between 8.3mm and 8.7mm, and
preferably 8.5mm. A distal end of each finger may diverge from the longitudinal axis
by a perpendicular distance of between 0.5mm and Imm, and preferably 0.7mm
The splayed fingers 22 are restrained in this diverging position, and the mechanical
20 deformation to the diverging position made permanent. The deformation is made
permanent by heat treating the fingers in the restrained position, such that the
fingers permanently extend in the diverging position. Preferably, the fingers 22 are
heat treated for 2 hours at 335°C + 5°C. In particular, the connection elements
with fingers are preferably heat treated for between 2 hours and 2 hours 10 minutes,
25 at between 330°C to 340°C. The fingers 22 are deformed linearly along their length,
such that each finger 22 is straight and orientated at an angle to the longitudinal axis
of the plug. Following this treatment the fingers 22 stay in the diverging position,
until forced radially inwardly by contact with the socket towards extending
longitudinally. Thus, the fingers 22 extend, by being deformed, in a direction
30 opposite to a direction in which they are urged by a co-operating connector.
The surface of the plug 10, and in particular, areas of the plug 10 configured to
contact a socket, have a very uniform surface finish. The fingers 22, and in
particular the profiled ends 28, have a surface finish better than 4pm. More
particularly, the surface finish is approximately, or better than, 1.2pm. The surface
finish is more preferably better than 0.4pm, in particular on the profiled ends 28.
The surface finish is preferably achieved by polishing.
5
The initial diverging position of the fingers 22 and the profiled ends 28 provide a
very high connection pressure with the outer element of the socket. In particular,
the heat treatment of the fingers in the diverging position means that a very large
force is required from a co-operating connector to resiliently deform the fingers
lo when making the connection. The heat treatment determines the mechanical
properties of the fingers, in particular, the heat treated fingers exert a very large
radial force when urged inwardly by the co-operating connector. In particular,
contacting areas of the outer connection element are forced together at a pressure
of at least approximately 70 MPa. This high pressure penetrates any metal oxide
I5 layers present, and so reduces intermodulation distortion.
Figure 3 shows a cross-section through the dielectric 30. The dielectric 30 has a
cylindrical outer surface 32 configured to fit closely within the body 20. The
dielectric 30 has a cylindrical channel 34 for receiving the pin 40.
20
The dielectric material is preferably formed from polytetrafluoroethylene (PTFE).
The dielectric 30 is a very good electrical insulator. The dielectric 30 isolates the
inner and outer connection elements 40.20 of the connector.
25 Figure 4 is a cross-section of the pin 40. The pin 40 comprises a first section 42,
which is cylindrical and configured to fit closely within the cavity 34 of the
dielectric 30. The pin 40 further comprises a second section 44, which is configured
to engage with the inner connection element of the socket. The second section 44 is
cylindrical adjacent the first section 42, with a diameter of between 1.2 and 1.5mm,
30 and preferably between 1.32mm and 1.37mm for a length of approximately 2.3mm.
The second section 44 has a circular cross section. The second section 44 has a
first tapered section 46, which tapers at between 1.5" and 3.5", and preferably at
approximately 2.5". A distal end of the second section 44 comprises a second
tapered section 48, which tapers at between 45" and 75", and preferably at
approximately 60" to a longitudinal axis. The second tapered section 48 terminates
in a planar distal end 49, extending perpendicular to the longitudinal axis. The
planar distal end 49 has a diameter of between 0.3 and 0.7mm, and preferably
5 0.44mm and 0.64mm.
The pin 40 is formed from beryllium copper. The beryllium copper is plated with a
layer of copper plate, preferably between lpm and 5pm, and more preferably 2pm +
lpm in thickness. A layer of silver plate is then applied onto the copper plate. The
lo silver plate is between 10pm and 30pm, and is preferably 15pm + 5pm in thickness.
The plating may be allowed to have a maximum thickness of 50pm on internal
corners. The plating materials and thicknesses have been selected to provide
optimum conductivity. Due the skin effect, electric current is substantially carried
by the outer silver layer.
15
The exterior surface, and in particular, areas of the pin 40 configured to contact a
socket, have a very uniform surface finish. The pin, and in particular, the second
section 44 has a surface finish better than 4pm. More particularly, the surface finish
is approximately or better than 1.2pm. The surface finish is more preferably less
20 than 0.4pm, in particular on the second section 44. The surface finish is preferably
achieved by polishing.
Figure 5 shows a socket 60 which is a connector according to the present invention.
The socket 60 may also be termed a jack receptacle or female connector. The
25 socket 60 is configured to connect with a co-operating plug. The socket 60 is a
TNC connector and comprises a body 70, a sleeve 80 and a probe 90. A restraining
material 71 prevents longitudinal movement between the body 70 and sleeve 80.
The body 70, sleeve 80 and probe 90 are of standard size, and so may be connected
to a co-operating plug shown in Figures 1 to 4, or to a co-operating known TNC
30 connector. The socket 60 comprises an inner connection element formed by probe
90, and an outer connection element formed by body 70.
Figure 6 shows the body 70 of the socket 60. The body 70 has a substantially
annular receptacle 72 at a first end. The receptacle 72 is configured to receive the
fingers 22 of the plug 10. An interior surface 76 of the receptacle 72 is dimensioned
to engage with the profiled ends 28 of the fingers 22. The receptacle 72 tapers
5 inwardly from an open end to a closed end. Preferably, the receptacle 72 tapers
smoothly from an interior diameter of between 8.31mm and 8.46mm to between
8.10mm and 8.15mm.
The body 70 comprises a threaded section 74 on an exterior surface of the
lo receptacle 72. The threaded section 74 is configured to mate with the threaded
section 52 of the plug 10.
The body 70 has a cavity 78 for receiving the dielectric 80. The cavity 78 is open to
the receptacle 72, along a longitudinal axis of the body 70. The cavity 78 comprises
I5 an annular recess 75. The annular recess 75 has a larger interior diameter than the
surrounding cavity 78. The cavity 78 is further provided with a stepped crosssectional
area 77 adjacent to the receptacle 72. The body 70 further comprises a
flange 79 surrounding the cavity 78. The flange is preferably substantially square
when viewed along the longitudinal axis of the body. Alternatively, the flange may
20 have any shape, for example, square, circular or hexagonal.
The body 70 is formed from an aluminium alloy. Preferably, the aluminium alloy
may comprise as % by weight: Si 0.50-0.90, Fe 0.5 max, Cu 3.9-5.0, Mn0.4-1.2, Cr
0.1, Mg 0.2-0.8, Ni O.lmax, Zn 0.25max, Ti & Zr 0.2max. The body 70 is preferably
25 formed from aluminium because the body is not required to resiliently deform, and
the use of aluminium reduces weight. Alternatively, the body may be formed from
stainless steel if weight is not critical. The aluminium alloy is plated with a layer of
nickel, preferably between 2pm and 10pm, and more preferably 5pm + lpm in
thickness. A layer of silver plate is then applied onto the nickel plate. The silver
30 plate is between 10pm and 30pm, and is preferably 15pm + 5pm in thickness. The
plating may be allowed to have a maximum thickness of 50pm on internal corners.
The plating materials and thicknesses have been selected to provide optimum
conductivity. Due the skin effect, electric current is substantially carried by the
outer silver layer.
The surface of the body 70, and in particular, areas of the body 70 configured to
5 contact a plug, have a very uniform surface finish. The body, and in particular, the
interior surface 76 of the receptacle 72 has a surface finish better than 4pm. More
particularly, the surface finish is approximately or better than 1.2 pm, 0.4 pm. The
surface finish is preferably achieved by polishing.
lo Figure 7 is a cross-sectional view of the dielectric 80. The dielectric 80 is located
within the body 70, and extends through the cavity 78 and into the receptacle 72.
The dielectric 80 comprises an annular sleeve 82 at a first end, locatable within the
receptacle 72 of the body 70. The sleeve 82 comprises a substantially cylindrical
channel 88 extending the length of the dielectric 80. The channel 88 receives the
I5 probe 90. The channel has an enlarged section 89 of larger diameter than the
remainder of the channel 88.
An outer surface of the dielectric 80 is configured to fit closely within the body 70.
The outer surface comprises a ring 84 of larger diameter than the surrounding
20 dielectric 80. The ring 84 is engagable in stepped cross-sectional area 77 of the body
70.
The outer surface of the dielectric 80 also comprises an annular recess 86. The
recess 86 in the dielectric 80 is aligned with matching annular recess 75 in the body
25 70. The aligned recesses 75,86 are keyed together with the restraining material 71 to
prevent relative longitudinal movement between the body 70 and dielectric 80.
Preferably, the restraining material 71 is a hardening adhesive. The aligned recesses
75,86 are filled with the adhesive. The adhesive may be injected as a liquid, and
harden within the aligned recesses 75,86 to a solid.
30
The dielectric 80 is formed as a split, matched pair of elements 82a,82b. The
dielectric 80 is split along a split line 87 to form the two elements 82a,82b. The
separable halves of the dielectric 80 allow the probe 90 to be located within the
channel 88.
The dielectric 80 is preferably formed from polytetrafluoroethylene (PTFE). The
5 dielectric 80 is a very good electrical insulator.
Figures 8a to 8c show the probe 90 forming the inner connection element of the
socket. The probe 90 is configured to fit in the channel 88 of the dielectric 80. The
probe 90 comprises fingers 92 at a first end of the probe, for contact around the pin
lo 40 of the plug 10, to form the inner electrical connection of the male connector. A
socket 94 is defined between the conductive fingers 92, the socket 94 configured to
receive the pin 40. The socket 94 has a cavity which is between 4.5mm and 6mm in
length, and is preferably 5.2mm in length.
I5 The fingers 92 are curved and arranged in an annulus, separated by slits 95. The
fingers 92 have a uniform cross-section along their length. Preferably, there are four
fingers 92, which are equally spaced and dimensioned.
The probe 90 comprises a collar 96. The collar 96 is configured to engage in the
20 enlarged section 89 of the dielectric 80, to prevent longitudinal movement of the
probe 90 within the dielectric 80.
The probe 90 is formed from beryllium copper. The beryllium copper is plated with
a layer of copper plate, preferably between lpm and 5pm, and more preferably 2pm
25 + lpm in thickness. A layer of silver plate is then applied onto the copper plate.
The silver plate is between 10pm and 30pm, and is preferably 15pm + 5pm in
thickness. The plating materials and thicknesses have been selected to provide
optimum conductivity. Due to the skin effect, electric current is substantially
carried by the outer silver layer.
30
The exterior surface, and in particular, areas of the probe 90 configured to contact
the plug, have a very uniform surface finish. The probe, and in particular, the
fingers have a surface finish better than 4pm. More particularly, the surface finish is
approximately or better than 1.2pm. The surface finish may be less than 0.4pm, in
particular on the interior surface of the fingers 92. The surface finish is preferably
achieved by polishing.
5 The probe 90 is formed with the fingers 92 orientated substantially parallel to a
longitudinal axis of the probe 90, e.g. by machining, as shown in Figures 8a and 8b.
The fingers 92 are formed with the socket 95 having an internal diameter of
between 1.3 and 1.5mm, and preferably between 1.39mm and 1.43mm. The slits 95
having a uniform width of between approximately 0.2mm and 0.3mm, preferably
lo between 0.250mm and 0.275mm. The slits 95 have a length of between 3.5mm and
4.5mm, and preferably 4mm.
Figure 8c shows part of the probe 90 during manufacture. The fingers 92 are
mechanically deformed together so that the distal ends of the fingers 92 are brought
15 into contact with each other. The slits 95 are closed at the distal ends of the fingers
92. A distal end of each finger may diverge from the longitudinal axis by a
perpendicular distance of between O.lmm and 0.3mm, and preferably between
0.17mm and 0.22mm.
20 The fingers 92 are restrained in this converging position and treated such that the
deformation to the converging position is made permanent. The mechanical
deformation is made permanent by heat treating the fingers in the restrained
position, such that the fingers permanently extend in the converging position.
Preferably, the fingers 92 are heat treated for 2 hours at 335°C + 5°C. In particular,
25 the connection elements with fingers are preferably heat treated for between 2
hours and 2 hours 10 minutes, at between 330°C to 340°C. The fingers 92 are
deformed linearly along their length, such that each finger 92 is straight and
orientated at an angle to the longitudinal axis of the socket. Following this
treatment, the fingers 92 stay in the converging position, until forced radially
30 outwardly by contact with the pin 40. Thus, the fingers 92 extend, by being
deformed, in a direction opposite to a direction in which they are urged by a cooperating
connector.
The initial converging position provides a very high connection pressure with the
inner connection element of the plug. In particular, the heat treatment of the
fingers in the converging position means that a very large force is required from a
co-operating connector to resiliently deform the fingers when making the
5 connection. The heat treatment determines the mechanical properties of the fingers,
in particular, the heat treated fingers exert a very large radial force when urged
outwardly by the co-operating connector. In particular the contacting areas are
forced together at a pressure of approximately 70 MPa. This high pressure
penetrates any metal oxide layers present, and so reduces intermodulation
10 distortion.
The fingers 92 are plated after the heat treatment has made the deformation
permanent. In order to plate all surfaces of the fingers 92, the fingers 92 are
resiliently urged apart during plating. The separation of the fingers 92 is such that
I5 the plating does not cover the slits. Preferably, the fingers 92 are urged into
extending approximately parallel to the longitudinal axis to be plated. The fingers 92
may preferably be held apart using wires or shims adjacent their deformed end, i.e.
close to an end opposite to the open end of the socket.
20 The present invention provides a method of manufacture of a connector. A
connector is formed having an outer connection element or inner connection
element having fingers, as described above. The fingers 22,92 are preferably formed
extending parallel to a longitudinal axis of the connector, for example, by
machining. The machining is preferably done with the material in a half hard
25 condition.
The fingers are mechanically deformed to a pre-determined angle to the longitudinal
axis of the plug or connector. The fingers are restrained at the pre-determined angle
to the longitudinal axis The fingers are then permanently deformed to the angle to
30 the longitudinal axis at which they are restrained. The deformation of the fingers
22,92 is made permanent by being heat treated, preferably for approximately two
hours at 335°C + 5°C. In particular, the connection elements with fingers are
preferably heat treated for between 2 hours and 2 hours 10 minutes, at between
330°C to 340°C.
The heat treatment causes the mechanical deformation of the fingers 22,92, to the
5 respective pre-determined angle to the longitudinal axis, to be permanent. The heat
treatment does not cause the deformation, the deformation is achieved mechanically
by restraining the fingers 22,92 in a deformed position. The subsequent heat
treatment results in a change in temper of the fingers 22,92 which makes the angle
permanent.
10
The amount of deformation and the stiffness of the fingers is sufficient to generate
high surface contact pressure with the mating parts. The contact pressure is
sufficient to substantially prevent the generation of intermodulation components
when the male and female halves of the connector are assembled. In particular,
15 contacting areas of the outer and inner connection elements are forced together at a
pressure of at least approximately 70 MPa. This high pressure penetrates any metal
oxide layers present, and so reduces intermodulation distortion to a very low level.
The fingers 22,92 are plated, preferably by electroplating, after the fingers 22,92
20 have been permanently deformed. In particular, the fingers are plated after the heat
treatment has made the deformation permanent. In order to plate all surfaces of the
fingers 92, the fingers 92 are resiliently urged apart during plating. Preferably, the
fingers 92 are urged into extending approximately parallel to the longitudinal axis to
be plated. The fingers 92 may preferably be held apart using wires or shims adjacent
25 their deformed end, i.e. close to an end opposite to the open end of the socket.
The whole of the plug body and socket probe are plated simultaneously with the
integral fingers 22,92.
During plating, the fingers 92 are held apart using wires or shims located in the slits
30 95 separating the fingers 92. The wires or shims only contact the fingers 92 on side
surfaces facing the slits 95. The wires or shims do not contact the inner curved
surfaces of the fingers 92. The areas of the fingers 92 in contact with the wires or
shims are not plated. This location of the wires or shims ensures that the curved
inner surfaces of the fingers 92, which define the socket and contact the pin 40, are
fully plated. The only areas which are not plated are on the side surfaces of the
fingers 92 defining the slits 95, which do not provide a contact surface of the
connector.
5
The wires or shims are preferably inserted into the slits 95 when the fingers are in a
permanently deformed position following heat treatment, as shown in Figure 8c.
The wires or shims are preferably inserted adjacent an end of the slit 95 distal from
the open end of the socket 94, i.e. on the right side of the slits 95 as shown in
lo Figure 8c. The slits 95 are widest towards this root end. For example, a first wire
may be inserted laterally into two diametrically opposite slits 95, i.e. extending
horizontally as shown in Figure 8b. A second wire may be inserted laterally into the
other two opposite diametrically opposite slits 95, i.e. extending vertically as shown
in Figure 8b.
15
After insertion in the slits 95, the wires or shims are moved toward the open end of
the socket 94, i.e. to the left as shown in Figure 8c. The wires or shims urge apart
the fingers 92, by movement of the wires or shims when in contact with both
adjacent fingers 92. The fingers 92 are then plated, and the wires or shims
20 withdrawn. The fingers 92 resiliently return to their original deformed orientation,
as shown in Figure 8c.
In use, a plug and socket according to the present invention are connected together
by engaging the threaded sections 52,74. Relative rotation between the plug and
25 socket causes the plug and socket to move longitudinally together. The fingers 22 of
the plug 10 are forced inwardly by contact with an interior surface of the receptacle
72 of the socket. The fingers 92 of the probe 90 are forced outwardly by contact
with the pin 40. Thus, the fingers 22,92 are configured to be urged towards the
longitudinal axis when fitted to a co-operating connector. A high pressure contact is
30 made between the inner connection elements 92,40 and the radially outer
connection elements 22,72, which provides for low passive intermodulation.
The electrically conducting parts of the plug and socket have been described as
plated with silver. Alternatively, the electrically conducting parts of the plug and
socket may be plated with gold. Preferably, both the plug and socket are plated with
the same metal to avoid distortion caused by dissimilar metal interfaces. A gold
5 layer has the advantage of being resistant to tarnishing. The gold layer is preferably
between 2pm and 10pm, and more preferably approximately 5pm thick, and is
plated on a layer of nickel, between 4pm and 15pm, and preferably of approximately
8pm thickness.
lo The base material for the conducting parts of the plug and the socket probe has
been described as beryllium copper. Alternatively, the base material for any of these
conducting parts, except for the connection elements 20,90 having resiliently
deformable fingers, may be aluminium or an aluminium alloy. The base material for
the socket body has been described as an aluminium alloy. Alternatively, the base
I5 material of the socket body may be beryllium copper. The base material may be
coated with any suitable first layer (e.g. copper, nickel) to allow a further conducting
layer (e.g. silver, gold) to affix to the base material.
The plug and socket connectors described are preferably used together in a
20 connector pair to minimise passive intermodulation distortion. Alternatively, one of
the plug or socket may be used with a standard TNC connector. The distortion
produced using a connector according to the present invention with a standard
TNC connector will be lower than when using two standard TNC connectors.
25 The fingers 22,92 have been described as extending at an angle to the longitudinal
axis of the plug or socket. Alternatively, the fingers 22,92 may extend substantially
parallel to the longitudinal axis. The low PIM may be provided by the profiled ends
of the fingers 22, and/or the surface finish, and/or any of the features described
above.
30
The plug and socket are described having dimensions within particular ranges. A
selection of dimension in one of the plug and socket may require a particular
dimension in the other of the plug and socket to allow co-operation.
The connectors have been described as TNC connectors, which may be joined by
threaded sections. Alternatively, the connectors may be BNC (Bayonet Neill-
Concelman) joined by bayonet mounts. Alternatively, the connectors may be any
other type of connector utilising a plurality of fingers to engage with a co-operating
5 part.
Any details not described may be the same as on a standard TNC connector. All
dimensions are stated including plating. Any of the features described may be used
on any embodiment, and in particular, may be used on either the socket or plug.

Claims
1. A method of manufacturing a connector comprising:
forming an outer connection element or inner connection element having
5 fingers,
deforming the fingers to an angle to a longitudinal axis; and
heat treating the connection element with the fingers restrained at the angle
to the longitudinal axis such that the fingers are permanently deformed to extend at
the angle to the longitudinal axis.
10
2. The method as claimed in claim 1 comprising initially forming the fingers
extending substantially parallel to a longitudinal axis of the connector.
3. The method as claimed in claim 1 or 2, wherein the connection element is
I5 plated following the heat treating of the connection element.
4. The method as claimed in any one of the preceding claims wherein the inner
connection element or outer connection element are formed from beryllium copper,
and/or plated with silver or gold.
20
5. The method as claimed in claim 4 wherein the silver is plated to a thickness
of between 10pm and 30pm, and more preferably 15pm + 5pm, or the gold is
plated to a thickness of between 2pm and 10pm, and more preferably 5pm + 2pm.
25 6. The method as claimed in any one of the preceding claims wherein a surface
of the fingers for contacting a co-operating connector is polished to 1.2pm or better
7. The method as claimed in any one of the preceding claims wherein the
connector is a plug, and the fingers form the outer connection element, wherein the
30 method comprises deforming and heat treating the fingers to diverge at an angle
relative to the longitudinal axis.
8. The method as claimed in claim 7 wherein a distal end of the fingers diverges
from the longitudinal axis by a lateral distance of between 0.5mm and Imm, and
preferably 0.7mm, and/or the outer connection element comprises twelve fingers
arranged in an annulus.
5
9. The method as claimed in any one of claims 1 to 6 wherein the connector is
a socket, and the fingers form the inner connection element, wherein the method
comprises restraining and heat treating the fingers to converge at an angle relative
to the longitudinal axis.
10
10. The method as claimed in claim 9 wherein the fingers are plated while urged
apart, following the heat treating of the inner connection element.
11. The method as claimed in claim 9 or 10 wherein a distal end of the fingers
I5 converges from the longitudinal axis by a lateral distance of between O.lmm and
0.3mm, and preferably between 0.17mm and 0.22mm, and/or the inner connection
element comprises four fingers.
12. The method as claimed in any one of the preceding claims wherein the
20 connector is a TNC connector and comprises a threaded portion to mate with a
threaded portion of a co-operating TNC connector.
13. A connector comprising:
an outer connection element and an inner connection element;
25 wherein one of the outer connection element and inner connection element
comprises a plurality of fingers extending at an angle relative to a longitudinal axis
of the connector,
wherein the fingers are formed by heat treating when deformed and
restrained at the angle to the longitudinal axis such that the fingers are permanently
30 deformed to extend at the angle to the longitudinal axis.
14. The connector as claimed in claim 13 wherein the fingers of the inner
connection element are plated while urged apart, following the heat treating of the
inner connection element.
5 15. The connector as claimed in claim 13 or 14 wherein the inner connection
element or outer connection element are formed from beryllium copper, and plated
with silver or gold.
16. The connector as claimed in claim 15 wherein the silver is plated to a
lo thickness of between 10pm and 30pm, and more preferably 15pm + 5pm, or the
gold is plated to a thickness of between 2pm and 10pm, and more preferably
5pm+2pm, and/or a surface of the fingers for contacting a co-operating connector
is polished to 1.2pm or better.
15 17. The connector as claimed in any one of claims 13 to 16 wherein contacting
areas of the inner connection element and/or outer connection element exert a
pressure of at least 70 MPa.