Electronic entity with magnetic antenna
An electronic entity ( 2 ) includes an electronic circuit ( 4 ) having connected thereto an antenna. The antenna includes a loop ( 6 ) electrically connected to the electronic circuit ( 4 ) and a resonator ( 8 ) coupled with the loop ( 6 ). The resonator ( 8 ) can be capacitively coupled to the loop. The resonator can be formed from a turn facing the loop ( 6 ) over at least a portion of its perimeter.
1. An electronic entity, comprising:
an electronic circuit to which is connected an antenna, wherein the antenna comprises a loop electrically connected to the electronic circuit and a resonator formed of a conductive winding with free ends coupled to said loop,
the loop being produced in a first plane,
the resonator being produced in a second plane different from the first plane, and
the resonator is in line with the loop.
2. The electronic entity according to claim 1 , wherein the resonator is capacitively coupled to the loop.
3. The electronic entity according to claim 2 , wherein the resonator comprises a turn facing the loop over at least a portion of a perimeter of the loop.
4. The electronic entity according to claim 3 , wherein the turn faces the loop over virtually all the perimeter of the loop.
5. The electronic entity according to claim 3 , wherein the turn and the loop are situated at a distance less than 0.5 mm over said perimeter portion.
6. The electronic entity according to claim 1 , wherein the loop forms a conductive circuit connected at each of its ends to a terminal of the electronic circuit.
7. The electronic entity according to claim 1 , wherein said conductive winding comprises a plurality of turns.
8. The electronic entity according to claim 7 , wherein the turns are separated two by two by a distance less than 0.5 mm.
9. The electronic entity according to claim 1 , wherein a median turn of the resonator is placed in line with the loop.
10. The electronic entity according to claim 1 , wherein a resonant frequency of the resonator alone is at most 10% higher than a communication frequency of the electronic circuit.
11. The electronic entity according to claim 1 , wherein the antenna is a magnetic antenna.
12. The electronic entity according to claim 1 , wherein the electronic circuit operates at a communication frequency below 100 MHz.
13. The electronic entity according to claim 12 , wherein said communication frequency is between 1 MHz and 50 MHz.
14. The electronic entity according to claim 13 , wherein said communication frequency is between 13 MHz and 15 MHz.
15. The electronic entity according to claim 14 , wherein the resonant frequency of the resonator alone is between 13.6 MHz and 17 MHz.
16. The electronic entity according to claim 1 , having exterior dimensions less than 100 mm.
17. The electronic entity according to claim 16 , wherein the resonator comprises more than ten turns.
18. The electronic entity according to claim 16 , wherein said exterior dimensions are less than 30 mm.
19. The electronic entity according to claim 1 , wherein the electronic entity is a pocket electronic entity.
20. The electronic entity according to claim 1 , wherein the electronic entity is a microcircuit card.
21. The electronic entity according to claim 20 , wherein the antenna extends over about half an area of the card.
22. The electronic entity according to claim 1 , wherein the resonator has a Q enabling amplification at a communication frequency of the electronic circuit.