RFID devices having multi-layer reactive straps and related systems and methods
View Patent ↗In some embodiments, an RFID device may include a multilayer reactive strap having a first substrate, a first conductor portion, a second conductor portion, and a first connection. The first conductor portion may enclose a first area and may be disposed on a first side of first substrate. A second conductor portion may enclose a second area and may be disposed on a second side of the first substrate. A first connection may couple the first conductor portion and the second conductor portion together, and may thereby form a multiturn coil that includes both the first conductor portion and the second conductor portion.
1. An RFID device comprising:
a multilayer reactive strap having
a first substrate;
a first conductor portion enclosing a first area and being disposed on a first side of first substrate;
a second conductor portion enclosing a second area and being disposed on a second side of the first substrate, and
a first connection coupling the first conductor portion and the second conductor portion together, thereby forming a multiturn coil that includes both the first conductor portion and the second conductor portion, wherein the multiturn coil of the connected first conductor portion and second conductor portion provides more inductance within a given area than a conductor having a single turn enclosing the same area.
2. The RFID device of claim 1 , wherein the first substrate is formed at least in part from a dielectric.
3. The RFID device of claim 1 , further comprising a radio frequency identification (RFID) chip coupled to the first conductor portion.
4. The RFID device of claim 1 , further comprising an antenna configured to be reactively coupled to the multilayer reactive strap.
5. The RFID device of claim 1 , further comprising a device substrate having a first side attached to the multilayer reactive strap and the antenna.
6. The RFID device of claim 1 , further comprising a second connection coupling the first conductor portion and the second conductor portion together.
7. The RFID device of claim 1 , wherein the first connection extends through the first substrate.
8. The RFID device of claim 1 , wherein the first dielectric substrate further comprises a flexible material.
9. The RFID device of claim 1 , wherein at least one of the first conductor portion and second conductor portion comprises a multiturn coil.
10. The RFID device of claim 1 , wherein each of the first conductor portion and second conductor portion comprises a multiturn coil.
11. The RFID device of claim 1 , wherein the first conductor portion and the second conductor portion comprise a different number of turns.
12. The RFID device of claim 1 , wherein a balance of the number of turns between the first conductor portion and second conductor portion and the relative locations of the first conductor portion and second conductor portion affects a near magnetic field of the multilayer reactive strap and coupling of the multilayer strap to an antenna.
13. The RFID device of claim 1 , wherein the number of turns of the first conductor portion and second conductor portion are distributed evenly on the first and second sides of the first dielectric substrate.
14. The RFID device of claim 1 , wherein the first conductor portion is connected to the second conductor portion by one or more of crimping, welding, or creating of plated through holes.
15. The RFID device of claim 1 , wherein the first conductor portion is connected to the second conductor portion by using a coupling capacitance between two areas of metal on either side of the first dielectric substrate.
16. The RFID device of claim 15 , wherein the RFID chip has a capacitance less than the coupling capacitance.
17. The RFID device of claim 1 , further comprising:
a second substrate; and
a third conductor portion,
wherein the second conductor portion includes a first side contacting the second side of the first substrate, and the second conductor portion includes a second side contacting a first side of the second substrate, and
wherein the third conductor portion includes a first side contacting a second side of the second substrate.
18. The RFID device of claim 17 , further comprising:
a third substrate; and
a fourth conductor portion,
wherein the third conductor portion includes a second side contacting a first side of the third substrate, and
wherein the fourth conductor portion includes a first side contacting a second side of the third substrate.
19. The RFID device of claim 18 , further comprising an antenna disposed on a device substrate and configured to be reactively coupled to the multilayer reactive strap.
20. The RFID device of claim 19 , wherein the device substrate forms one of the first substrate, the second substrate, or the third substrate.
21. A method of forming an RFID device comprising:
forming a multilayer reactive strap by
disposing a first conductor portion enclosing a first area on a first side of the first substrate,
disposing a second conductor portion enclosing a second area on a second side of the first substrate,
using a first connection, coupling the first conductor portion and the second conductor portion together, thereby forming a multiturn coil that includes both the first conductor portion and the second conductor portion, wherein the first conductor portion is connected to the second conductor portion by using a coupling capacitance.
22. The method of claim 21 , wherein the first substrate is formed at least in part from a dielectric.
23. The method of claim 21 , further comprising
coupling a radio frequency identification (RFID) chip to the first conductor portion.
24. The method of claim 21 , further comprising
attaching an antenna to a device substrate; and
attaching the multilayer reactive strap to the device substrate,
wherein the antenna is configured to be reactively coupled to the multilayer reactive strap.
25. The method of claim 24 , wherein the multilayer reactive strap and the antenna are both attached to a first side of the device substrate.
26. The method of claim 21 , further comprising
using a second connection, coupling the first conductor portion and the second conductor portion together.
27. The method of claim 21 , wherein at least one of the first conductor portion and second conductor portion comprises a multiturn coil.
28. The method of claim 21 , wherein each of the first conductor portion and second conductor portion comprises a multiturn coil.
29. The method of claim 21 , wherein the first conductor portion and the second conductor portion comprise a different number of turns.
30. The method of claim 21 , wherein the number of turns of the first conductor portion and second conductor portion are distributed evenly on the first and second sides of the first dielectric substrate.
31. The method of claim 21 , wherein the first conductor portion is connected to the second conductor portion by one or more of crimping, welding, or creating of plated through holes.
32. The method of claim 21 , further comprising:
attaching a first side of a second substrate to a second side of the second conductor portion; and
attaching a first side of a third conductor portion to a second side of the second substrate.
33. The method of claim 32 , further comprising:
attaching a first side of a third substrate to a second side of the third conductor portion; and
attaching a first side of a fourth conductor portion to a second side of the third conductor portion.
34. The method of claim 33 , wherein the device substrate forms one of the first substrate, the second substrate, or the third substrate.