Antenna connection, particularly for surface guided elastic wave transducers
An electrical device adapted to operate at a high operating ambient temperature includes an electrical component mounted inside a casing, a transmission/reception antenna and at least one electrical and mechanical connection between the electrical component and the antenna. The electrical and mechanical connection comprises a metal pad positioned under the casing, the antenna being connected to the pad; an electrical connection tab having a first end connected to the electrical component; and fixing means adapted to secure the pad and a second end of the connection tab of the component. The device is applicable to, for example, temperature sensors of the surface guided elastic wave type.
1. An electrical device suitable for operating at an operating ambient temperature of higher than 300° C., the device comprising:
a casing;
an electrical component mounted inside the casing;
a transmission/reception antenna positioned outside the casing; and
at least one electrical and mechanical connection between the electrical component and a pole of the transmission/reception antenna, the electrical and mechanical connection including:
a metal pad having a connection surface positioned against a surface of the casing, the pole of the transmission/reception antenna being connected to the metal pad;
an electrical connection tab having a first end connected to the electrical component; and
a fixing device securing together the metal pad, the casing, and a second end of the electrical connection tab; and
wherein the metal pad includes a groove extending to a clearance surface of the metal pad, a fastening end of the pole of the transmission/reception antenna disposed in the groove.
2. The electrical device of claim 1 , wherein the metal pad comprises a bearing surface on a side thereof opposite the casing.
3. The electrical device of claim 2 , wherein the bearing surface is covered with an electrically insulating covering.
4. The electrical device of claim 1 , wherein the groove extends into the connection surface of the metal pad.
5. The electrical device of claim 4 , wherein an end of the pole of the transmission/reception antenna comprises an anchoring head having a cross-section size and/or shape different from a cross-section size and/or shape of a remainder of the pole of the transmission/reception antenna.
6. The electrical device of claim 5 , wherein an interference fit is provided between the groove and the pole of the transmission/reception antenna.
7. The electrical device of claim 6 , wherein:
the metal pad comprises a first hole;
the casing includes a second hole axially aligned with the first hole in the metal pad; and
the fixing device comprises a screw that cooperates with the second hole in the casing to electrically and mechanically connect the electrical connection tab and the metal pad to the casing.
8. The electrical device of claim 1 , wherein the metal pad includes a pin extending from the connection surface of the metal pad, a free end of the pin being adapted for:
cooperating with a nut or a retaining pin; or
being crimped to form a rivet.
9. The electrical device of claim 1 , wherein the groove of the metal pad is open on a surface of the metal pad that is distinct from the connection surface and that is distinct from the clearance surface, wherein the metal pad includes a first hole extending to the groove, and the casing includes a second hole axially aligned with the first hole in the metal pad, wherein a distal portion of the pole of the transmission/reception antenna is bent to form a pin, and wherein the pin is adapted to pass through the first hole in the metal pad, to pass through the second hole in the casing, and to extend into the casing when an end of the pole of the transmission/reception antenna is engaged in the groove, a free end of the pin being adapted for:
cooperating with a nut or a retaining pin; or
being crimped to form a rivet.
10. The electrical device of claim 2 , further comprising a second metal pad having a connection surface positioned against a surface of the casing, the second metal pad forming a ground for the transmission/reception antenna or being arranged to be connected to a ground that is external to the electrical device.
11. The electrical device of claim 1 , wherein the transmission/reception antenna includes two poles, and further comprising at least two electrical and mechanical connections, each of which connects the electrical component to one of the poles of the transmission/reception antenna, each electrical and mechanical connection comprising:
a metal pad having a connection surface positioned against a surface of the casing, the associated pole of the transmission/reception antenna being connected to the metal pad, the metal pads of the two electrical and mechanical connections being distinct from each other;
an electrical connection tab having a first end connected to the electrical component; and
a fixing device securing the metal pad and a second end of the electrical connection tab to the casing.
12. The electrical device of claim 11 , wherein the metal pads of the two electrical and mechanical connections are separated by a spacer comprising an electrically insulating material.
13. The electrical device of claim 11 , wherein an inductive or capacitive impedance is connected between the metal pads of the two electrical connections.
14. The electrical device of claim 1 , wherein an end of the pole of the transmission/reception antenna comprises an anchoring head having a cross-section size and/or shape different from a cross-section size and/or shape of a remainder of the pole of the transmission/reception antenna.
15. The electrical device of claim 1 , wherein an interference fit is provided between the groove and the pole of the transmission/reception antenna.
16. The electrical device of claim 1 , wherein:
the metal pad comprises a first hole;
the casing includes a second hole axially aligned with the first hole in the metal pad; and
the fixing device comprises a screw that cooperates with the second hole in the casing to electrically and mechanically connect the electrical connection tab and the metal pad to the casing.