RELATED TELEMETERING DEVICE

The present invention relates to a connector assembly comprising an antenna, wired to a printed circuit board and adapted to be connected to a transceiver circuit, and an electromagnetic shield. The present invention also relates to a telemetering device, e.g. a device for measuring the consumption of energy and/or of a resource, e.g. electric energy, and/or a fluid, e.g. water, and/or a gas, e.g. a fuel .

It is known that consumer electronic devices, in particular intended for household use, must comply with stringent electromagnetic compatibility requirements.

In those electronic devices which include a transceiver circuit, where signals are transmitted by means of an antenna, the transceiver circuit must be appropriately shielded electromagnetically in order to prevent the transceiver circuit from emitting electromagnetic waves in undesired directions and/or frequency spectra.

In addition, the antenna device must be suitably impedance-coupled to the transceiver circuit for the purpose of obtaining the highest gain in the signal transmission through the antenna itself.

More specifically, it is required that the signal transmission antenna be impedance-coupled correctly, and that the same be proximal to the transceiver circuit, which must be appropriately shielded, e.g. by means of a metallic structure . Some currently known solutions are described in prior document EP3425728A1, which illustrates in detail two different design approaches.

A first approach envisages to mechanically connect the antenna to a printed circuit board or PCB whereon a communication line is connected, the latter being adapted to be connected to the transceiver circuit. Said communication line is impedance-coupled to the antenna. The impedance coupler is at least partly implemented on the PCB.

On the printed circuit board or PCB, which is distinct and separate from said transceiver circuit, at least a pair of clips are also electrically connected, which are adapted to mechanically and electrically connect a shield, made of metallic material, to the printed circuit board, connecting said shield to ground.

Such a solution has proven to be not very reliable, since said clips are prone to losing their shape memory, thus not ensuring the electric contact, and sometimes not even the mechanical connection, with said shield over time. Furthermore, such a solution is costly as far as the assembly process is concerned, because it is necessary to electrically and mechanically connect at least two clips to the PCB in order to at least try to ensure the electronic and mechanical connection with said shield.

The other solution described in the above-mentioned prior-art document consists in constructing said shield, said printed circuit board and part of the antenna coupling circuit as a single element, e.g. made of metallic material. Therefore, multiple elements of the connector assembly are implemented in a single piece. Such a solution, although it simplifies the assembly process and partly reduces the production costs, has shown to suffer from some technical problems as concerns the mechanical strength of the assembly. In fact, this solution is subject to breaking and/or deformation. In particular, since the element is made from metallic material in sheet form, to one end of which an antenna is mechanically coupled, and includes a portion having a reduced cross-section to implement the impedance coupling, mechanical and electronic problems may arise due to breaking and/or deformation.

Therefore, the solutions currently known in the art have some shortcomings that do not permit obtaining an optimal solution as regards both the electronic and the mechanical aspects.

Moreover, the need is increasingly felt for reducing as much as possible the costs incurred for manufacturing such assemblies, while still complying with very stringent mechanical and electronic constraints.

Such technical problems are especially perceived for consumer products to be used in domestic environments, which are subject to more stringent electromagnetic compatibility requirements. In particular, this problem affects measuring devices or meters, e.g. telemetering devices, used for measuring energy consumption, e.g. electric energy consumption .

The present invention aims at solving the above- mentioned technical problems and other problems as well by providing a connector assembly comprising an antenna, a printed circuit board or PCB, and an electromagnetic shield, wherein the electric and mechanical connection between the shield and the printed circuit board or PCB is considerably improved while nevertheless reducing the production costs.

One aspect of the present invention relates to a connector assembly having the features set out in the appended claim 1.

A further aspect of the present invention relates to a telemetering device having the features set out in the appended claim 12.

Auxiliary features of the assembly and device are set out in respective dependent claims.

The features and advantages of the assembly and device will become apparent in the light of the following description of several possible embodiments of the assembly and device, as well as from the annexed drawings, wherein:

• Figure 1 shows an axonometric view of one possible embodiment, provided by way of non-limiting example, of the connector assembly according to the present invention;

• Figures 2A and 2B show two plan views of the connector assembly of Figure 1; in particular, Figure 2A shows the connector assembly in a top view; Figure 2B shows the connector assembly in a bottom view;

• Figure 3 shows a side sectional view relative to the vertical plane 3-3 of the connector assembly of Figure 2A;

• Figure 4 shows a detail of the section shown in Figure 3;

• Figure 5 shows an exploded view of the connector assembly, which also illustrates at least a portion of the transceiver circuit of the telemetering device to be shielded by the shield of the connector assembly according to the present invention. With reference to the above-listed figures, reference numeral 2 designates as a whole the connector assembly comprising an antenna, a printed circuit board and a shield.

Reference numeral 1 designates as a whole a telemetering device .

Connector assembly 2 according to the present invention is particularly suitable for application to telemetering devices 1.

Connector assembly 2 according to the present invention comprises: an antenna 3, adapted to be connected to a transceiver circuit 12 through a transmission line 4; a printed circuit board or PCB 5, whereon an electronic circuit 52 is realized, to which said antenna 3 is electronically connected; and a shield 7, made of metallic material, adapted to electromagnet ically shield said transceiver circuit 12, e.g. for the purpose of shielding the electromagnetic waves emitted by said transceiver circuit 12 and/or the electromagnetic waves directed towards the same transceiver circuit 12.

Said printed circuit board or PCB 5 comprises one or more pads 53 of conducting material, e.g. copper, adapted to be connected to a ground point or ground of electronic circuit 52.

Said shield 7 is adapted to be mechanically connected to said printed circuit board or PCB 5 and electronically connected to ground, in particular to the ground of electronic circuit 52.

In the preferred embodiment of connector assembly 2 according to the present invention, said shield 7 comprises one or more connection portions (72, 74, 76), each one adapted to directly interact with said printed circuit board or PCB 5.

At least a connection portion 72 comprises, in turn, a contact element 722 adapted to act upon at least a pad 53, by applying a thrust force on said pad 53, in order to ensure the electric connection to ground, in particular a connection to the ground of electronic circuit 52.

Said one or more connection portions (72, 74, 76) are adapted to ensure a mechanical connection between said shield 7 and said printed circuit board or PCB 5.

In the present embodiment, thanks to said one or more connection portions (72, 74, 76) formed in the structure of shield 7, it is possible to realize the electric and mechanical connection to printed circuit board or PCB 5 while reducing the manufacturing and assembly costs and ensuring an adequate level of durability and reliability over time of the electric and mechanical connections.

In particular, the present solution makes it possible to establish a mechanical constraint between printed circuit board or PCB 5 and said shield 7 for the purpose of keeping them in the correct position, e.g. with respect to said transceiver circuit 12. Preferably, printed circuit board or PCB 5 is mechanically constrained to shield 7.

In a preferred, but non-limiting, embodiment, said printed circuit board 5 and said transceiver circuit 12 are two distinct elements.

In particular, said one or more connection portions (72, 74, 76) are formed directly in shield 7, being integral parts of shield 7 itself, e.g. as a monolithic element; for example, said connection portions cannot be separated from said shield unless the shield is destroyed and functionally impaired .

In a preferred, but non-limiting, embodiment of connector assembly 2 according to the present invention, said shield 7 comprises at least two connection portions (72, 74) . In one possible variant, said shield comprises at least a first connection portion 72 and at least a second connection portion (74, 76) .

Said at least one first connection portion 72 comprises said contact element 722, in order to ensure the electric connection .

Said at least one second connection portion (74, 76) is at least adapted to ensure the mechanical connection between shield 7 and printed circuit board or PCB 5.

Said at least one second connection portion (74, 76) is distinct from said at least one first connection portion 72.

In the present embodiment of shield 7 it is possible to ensure, by means of at least two distinct connection portions, a stable electric and mechanical connection while reducing the costs incurred for manufacturing and assembling connector assembly 2 according to the present invention.

In one possible variant, said at least one second portion (74, 76) can contribute to ensuring the electric connection of shield 7 to ground.

In a further possible variant, said at least one first portion 72 can contribute to ensuring the mechanical connection of shield 7 to printed circuit board or PCB 5.

In an even more preferable, though merely exemplificative and non-limiting, embodiment of connector assembly 2 according to the present invention, a third connection portion 76 is comprised in addition to a second connection portion 74.

In particular, said third connection portion 76 and said second connection portion 74 are two distinct connection portions. Preferably, said third connection portion 76 and said second connection portion 74 are adapted to ensure at least the mechanical connection between shield 7 and printed circuit board or PCB 5.

In the present embodiment multiple connection portions are implemented to ensure the mechanical connection between shield 7 and printed circuit board or PCB 5, for the purpose of making sure that there is a reliable mechanical connection between shield 7 and printed circuit board or PCB 5 and avoid an electric disconnection of shield 7 from ground.

Said third connection portion 76 and said second connection portion 74 may possibly contribute to ensuring the connection to ground by providing shield 7 with a redundancy of ground contact points, e.g. in contact with said pads 53.

Preferably, said shield 7 is realized as a metallic plate, the thickness of which is much smaller than its other dimensions .

Said shield 7 may be a continuous flat plate or a plate comprising a plurality of holes. In the embodiment comprising said holes, the size of said holes is such that shield 7 is still a continuous flat surface for the wavelength of the electromagnetic signal emitted by said transceiver circuit. Said holes may contribute to the air exchange useful for cooling transceiver circuit 12.

More in general, in a preferred embodiment of connector assembly 2 according to the present invention said contact element 722 is a part of shield 7 suitably shaped to generate a thrust force on said printed circuit board or PCB 5, e.g. on said pads 53, particularly when shield 7 is assembled to printed circuit board or PCB 5.

This solution permits exploiting the elastic characteristics of metallic shield 7 to generate a thrust force that will ensure a reliable and durable contact between shield 7 and pads 53.

In one possible embodiment of said contact element 722, it is a plate cut in shield 7. Said plate is appropriately bent to generate a cantilever. Said plate is such that, when shield 7 is connected to printed circuit board or PCB 5, contact element 722 will deform, thereby generating a thrust force on said pads 53, due to the elastic and shape-memory characteristics of the metallic material employed for making shield 7.

In one possible embodiment, said contact element 722 comprises one or more bending points, so as to generate at least one portion of said contact element 722 that lies in a plane parallel to the plane defined by shield 7, e.g. said contact element 722 comprises at least to bending points, so as to define a surface parallel to the surface defined by shield 7.

Describing now more in detail further construction aspects of connector assembly 2 according to the present invention, said second connection portion 74 comprises at least one catching element 742. Said catching element 742 is adapted to generate a mechanical constraint with said printed circuit board or PCB 5.

In one possible embodiment of the connector assembly 2, said third connection portion 76 comprises at least a retaining element 762, which is adapted to generate a mechanical constraint with said printed circuit board or PCB

5.

In a preferred embodiment of connector assembly 2, said catching element 742 is designed to realize a structure having a C-shaped cross-section. Even more preferably, said retaining element 762 is designed to realize a structure having a C-shaped cross-section.

Said catching element 742 and/or said retaining element 762 are made by appropriately bending a portion of shield 7 to create a structure having a C-shaped cross-section.

More in general, said printed circuit board or PCB 5 can be received between the ends of the structure having a C-shaped cross-section of said catching element 742 and/or said retaining element 762. Said structure having a C-shaped cross-section can also perform a guiding function, permitting the coupling between shield 7 and printed circuit board or PCB 5 by means of a relative sliding movement of the two parts of connector assembly 2 according to the present invention.

Preferably, the structures having a C-shaped cross- section of said catching element 742 and said retaining element 762 face towards and are parallel to each other, thus performing the guiding function.

More in general, said one or more connection portions (72, 74, 76) make it possible to connect said shield 7 to printed circuit board or PCB 5, in order to realize said connector assembly 2, thanks to a relative sliding movement between said shield 7 and said printed circuit board or PCB 5. In a preferred, but non-limiting, embodiment of connector assembly 2 according to the present invention, said printed circuit board or PCB 5 comprises a cut-out 54. Said cut-out 54 forms a through groove. Said cut-out 54 extends perpendicularly from an edge of printed circuit board or PCB 5.

Said cut-out 54 is adapted to receive a retaining or catching element (742, 762) of at least a connection portion (74, 76) of shield 7, particularly for the purpose of ensuring the mechanical connection between said shield 7 and said printed circuit board or PCB 5.

Alternatively, said printed circuit board or PCB 5 comprises a portion suitably shaped to lie between said second connection portion 74 and said third connection portion 76; even more preferably, said portion of printed circuit board or PCB 5 sets itself between the ends of the structures having a C-shaped cross-section of said catching element 742 and said retaining element 762.

As a further alternative, said shield 7 is shaped in a manner such that said second connection portion 74 and said third connection portion 76 act upon two sides, preferably parallel to each other, of the printed circuit board or PCB 5.

Said shield 7 is made of metallic material, preferably brass .

This material has particular mechanical and elasticity characteristics which last over time, featuring a shape memory that ensures a durable and reliable electric and mechanical connection to printed circuit board PCB 5.

Preferably, said shield 7 comprises a coupling edge. Said coupling edge allows said shield 7 to be connected over transceiver circuit 12 of telemetering device 1. Said coupling edge is designed to generate a shape coupling, preferably a releasable one, e.g. by snapping and/or interference, to a containment structure of said transceiver circuit 12.

Describing now more in depth the construction details of connector assembly 2 according to the present invention, said antenna 3 comprises connection elements 32 for electrically connecting antenna 3 to electronic circuit 52 realized on printed circuit board or PCB 5.

Said electronic circuit 52 comprises a connection portion 522 to which said transmission line 4 is connected. An impedance adapter 55 is also connected to said connection portion 522 of the electronic circuit. Said impedance adapter 55 is adapted to adapt the impedance between antenna 3 and transmission line 4.

In one possible embodiment, said impedance adapter 55 is provided as a stub, whether in series or in parallel.

Said impedance adapter 55 may be realized directly in said electronic circuit 52 of printed circuit board or PCB 5, e.g. as a copper track of the printed circuit board, or may be a discrete component electronically and mechanically connected to electronic circuit 52.

In one possible embodiment, said transmission line 4 comprises, at one end thereof, a connector 44 adapted to be connected to said transceiver circuit 12. At the opposite end of transmission line 4 there is a ground connection 42 and a connection to electronic circuit 52 of printed circuit board or PCB 5, in particular to connection portion 522. Said transmission line 4 is realized, for example, as a coaxial cable. In a preferred, but non-limiting, embodiment, said antenna 3 is a helical antenna.

More in general, the type of electric and mechanical connection of shield 7 implemented in connector assembly 2 according to the present invention is also applicable to other assemblies with different types of antenna 3, transmission line 4 and electronic circuit 52 realized on said printed circuit board or PCB 5.

Connector assembly 2 according to the present invention is particularly suitable for use in telemetering devices 1, or in other electronic devices comprising an antenna and a transceiver circuit to be conveniently shielded.

In particular, said telemetering device 1 is adapted to measure a physical quantity, e.g. a device for metering the consumption of energy and/or of a resource, e.g. electric energy, and/or a fluid, e.g. water, and/or a gas, e.g. a fuel .

Preferably, said telemetering device 1 comprises a transceiver circuit 12 adapted to generate a signal for transmitting data relating to measurements of said physical quantity .

Preferably, said transceiver circuit 12 can transmit in the 169MHz and/or 868MHz bands or other free and/or ISM frequencies .

Said telemetering device 1 comprises a connector assembly 2 according to the present invention, which comprises a shield 7 adapted to shield the electromagnetic waves emitted by said transceiver circuit 12. Said shield 7 comprises one or more connection portions (72, 74, 76) adapted to ensure an electric and mechanical connection between said shield 7 and said printed circuit board or PCB

5.

In one possible embodiment, said telemetering device 1 is assembled by executing the following steps, preferably in succession, preferably for assembling connector assembly 2 to transceiver circuit 12:

- electrically connecting said transceiver circuit 12 onto a support, e.g. a printed circuit board;

- positioning said shield 7 over said transceiver circuit 12, preferably by fixing a coupling edge of shield 7 on top of said transceiver circuit 12;

- electrically connecting said antenna 3 to the printed circuit board or PCB 5;

- mechanically connecting said printed circuit board or PCB 5 to the shield 7.

Preferably, the step of connecting said printed circuit board or PCB 5 to shield 7 is carried out by sliding printed circuit or PCB 5 towards said shield 7, the latter being already fastened to said transceiver circuit 12, so as to effect the mechanical and electric connection as previously specified .

Figure 5 shows an exploded view of connector assembly 2, illustrating also at least one portion of transceiver circuit 12 of a telemetering device 1. Said transceiver circuit 12 is adapted to be electromagnetically shielded by shield 7 of connector assembly 2 according to the present invention .

In the illustrated embodiment, said shield 7 has such a shape as to substantially cover said transceiver circuit 12, except for a portion where connector 44 of transmission line 4 is adapted to be electronically connected to transceiver circuit 12.

Figure 5 clearly illustrates one possible embodiment of the first connection portion 72, the second connection portion 74 and the third connection portion 76 comprised in shield 7.

In Figure 5 it is possible to see that said contact element 722 of the first connection portion 72 is suitably bent to lie in a plane other than the plane defined by the surface of shield 7. Furthermore, Figure 5 shows one possible "C" conformation of catching element 742 of the second connection portion 74 and of retaining element 762 of the third connection portion 76.

Figure 5 also shows one possible embodiment of pad 53 of electronic circuit 52, which will be acted upon by contact element 722 of the first connection portion 72 of shield 7.

In Figure 5 it is also possible to see one possible embodiment of cut-out 54, which is adapted to receive said third connection portion 76 when shield 7 is assembled to printed circuit board or PCB 5.

Figure 5 also shows one possible embodiment of connection portion 522 of electronic circuit 52 to which said transmission line 4 is connected, including ground connection 42 of the same transmission line 4.

Figure 5 additionally shows, by way of example, an antenna 3 of the helical type, covered by a protective layer.

In Figure 5 one can also identify the coupling edge through which the shield can be secured over said transceiver circuit 12. Figure 1 shows an axonometric view of one possible embodiment, provided herein by way of non-limiting example, of connector assembly 2 according to the present invention.

In particular, Figure 1 shows connector assembly 2 of Figure 5 in the assembled condition.

In Figure 1 it is possible to see how said shield 7, and in particular said connection portions (72, 74), act upon said printed circuit board or PCB 5 to ensure the electric and mechanical connection.

From Figure 1 one can also infer one possible relative position between printed circuit board 5 and the connection portions (72, 74), and where said contact element 722 will act upon printed circuit board or PCB 5.

In Figure 1 one can identify the position where transmission line 4 will be connected to a transceiver circuit 12 through said connector 44.

In Figure 1 one can also identify a part of electronic circuit 52 comprised in printed circuit board or PCB 5, such as, for example, impedance adapter 55.

Figure 2A shows a top view of connector assembly 2, where it is possible to see one possible disposition of the first connection portion 72 and of contact element 722 in shield 7.

In the illustrated embodiment, contact element 722 has a substantially rectangular shape, realized in the surface of shield 7.

Figure 2A also shows one possible embodiment of printed circuit board or PCB 5 comprising a cut-out 54, in which a part of shield 7 can be housed when shield 7 is assembled to printed circuit board or PCB 5, e.g. by making a linear sliding movement. Figure 2A also shows one possible embodiment of ground connection 42 of transmission line 4 and of connection portion 522 of electronic circuit 52 and impedance adapter 55.

Although not visible in Figure 2A, at least one pad 53 of electronic circuit 52, connected to ground, is present in printed circuit board or PCB 5, where catching element 742 of the second connection portion 74 comes to be located when the shield is assembled to printed circuit board or PCB 5.

Figure 2B shows a bottom view of connector assembly 2, wherein it is possible to see one possible arrangement of the second connection portion 74, with the respective catching element 742, and of the third connection portion 76, with the respective retaining element 762, in shield 7.

From Figure 2B it is possible to understand how said third connection portion 76 is housed within cut-out 54 formed in said printed circuit board or PCB 5.

Figure 3 shows a side sectional view relative to a vertical plane 3-3 of connector assembly 2 of Figure 2A. In this figure one can see the substantially planar structure of shield 7, and the relative positioning of said first connection portion 72 and said third connection portion 76 with respect to both shield 7 and printed circuit board or PCB 5, when shield 7 is assembled to printed circuit board or PCB 5.

This figure also shows an embodiment of antenna 3, in particular a helical antenna, connection elements 32 of which are conveniently connected to electronic circuit 52 of printed circuit board or PCB 5. Figure 4 shows a part of the section shown in Figure 3, wherein further details of the section shown in Figure 3 are visible .

This figure clearly shows the shape assumed by contact element 722 of the first connection portion 72, which acts upon a pad 53 of electronic circuit 52 realized on printed circuit board or PCB 5, when shield 7 is assembled to printed circuit board or PCB 5. Said transmission line 4 is also conveniently connected to said electronic circuit 52.

From Figure 4 it is also possible to infer one possible conformation of retaining element 762 of the third connection portion 76, which surrounds part of the edge of cut-out 54 formed in said printed circuit board or PCB 5.

Figure 4, just like the previously described Figure 3 and Figure 5, shows the presence of a coupling edge useful for placing the shield over transceiver circuit 12.

Connector assembly 2 according to the present invention no longer requires the use of additional connection elements, e.g. clips, for connecting the shield to the printed circuit board, since the connection portions are directly comprised and realized in shield 7.

Any alternative embodiments or variants which have not been described herein in detail, but which can be easily inferred by a person skilled in the art in light of the present description and the annexed drawings, shall be considered to fall within the technical contents of the present invention.

REFERENCE NUMERALS

Telemetering device 1 Transceiver circuit 12

Connector assembly 2

Antenna 3

Connection elements 32 Transmission line 4

Ground connection 42

Connector 44

Printed circuit board or PCB 5

Electronic circuit 52 Connection portion 522

Pads 53

Cut-out 54

Impedance adapter 55

Shield 7 First connection portion 72

Contact element 722

Second connection portion 74

Catching element 742

Third connection portion 76 Retaining element 762