Fastening element for magnetically fastening an electronic module, set comprising such a fastening element and an electronic module

1. A fastening element for magnetically fastening an electronic module, the fastening element being configured to be fixed to a support, the support having a recess, the electronic module including a radioelectric antenna and a display screen, the radioelectric antenna having a characteristic wavelength, the display screen being visible through the recess when the fastening element is fixed to the support and fastened to the electronic module,

the fastening element being configured to be fixed around the recess,

wherein the fastening element comprises several portions, at least some portions being separate from each other by a respective gap for emission and/or reception of radio waves by the radioelectric antenna, and

wherein at least one portion has a length depending on the characteristic wavelength.

2. The fastening element according to claim 1 , wherein several portions of the fastening element have a respective length depending on the characteristic wavelength.

3. The fastening element according to claim 1 , wherein the length depending on the characteristic wavelength is the greatest length of the corresponding portion.

4. The fastening element according to claim 1 , wherein the length depending on the characteristic wavelength is substantially equal to a quarter of the characteristic wavelength of the radio antenna.

5. The fastening element according to claim 1 , wherein each portion with a length depending on the characteristic wavelength has a rectangular shape.

6. The fastening element according to claim 1 , wherein the measure of each gap between two successive portions is comprised between 1 mm and 3 mm.

7. The fastening element according to claim 1 , wherein the fastening element is a metallic element.

8. The fastening element according to claim 7 , wherein the metallic element is a metallic yarn element.

9. A set comprising:

a fastening element configured to be fixed to a support, the support having a recess;

an electronic module magnetically fastened to the fastening element, the electronic module including a radioelectric antenna and a display screen, the radioelectric antenna having a characteristic wavelength, the display screen being visible through the recess,

wherein the fastening element is according to claim 1 .

10. The set according to claim 9 , wherein the portion(s) with a length depending on the characteristic wavelength is (are) the portion(s) closest to the radioelectric antenna.

11. The set according to claim 9 , wherein the portions of the fastening element are disposed around at least two sides of the recess.

12. The set according to claim 9 , wherein the electronic module is substantially planar and the length depending on the characteristic wavelength is the greatest length of the corresponding portion in a plane substantially parallel to the electronic module.

13. The set according to claim 9 , wherein the electronic module includes a magnetic frame for being magnetically fastened to the fastening element, the magnetic frame generating a magnetic field, and

wherein the fastening element is substantially perpendicular to the magnetic field generated by the magnetic frame.

14. The set according to claim 9 , wherein the set further comprises the support having the recess.

15. The set according to claim 14 , wherein the support is a yarn support.

16. The set according to claim 14 , wherein the support is a wearable article of clothing.