Method and apparatus for protecting culinary products
View Patent ↗A microwave-resistant and waterproof security tag for use with food products, especially meat products. The security tag includes a pair of single, open loop conductive traces in between which is disposed a similarly-shaped dielectric layer. This combination is encapsulated within plastic membranes or covers that are sealed at their common edges. The preferred embodiment includes rectangularly-shaped single, open loop conductive traces with rounded corners and with one end of each trace forming a capacitor plate. The width of each trace is at least 1/10 of the length of the security tag.
1. A security element that is microwave-resistant, said security element comprising:
a first conductive trace forming a first single open loop conductor;
a second conductive trace forming a second single open loop conductor;
a dielectric layer forming a single open loop insulator and positioned between said first and second conductive traces;
said first and second conductive traces being electrically-coupled at a location that penetrates said dielectric layer; and
wherein said first conductive trace, said second conductive trace and said dielectric layer are encapsulated within plastic layers.
2. The security element of claim 1 wherein said first and second single open loop conductors and said single open loop insulator each comprise at least three elbows.
3. The security element of claim 2 wherein each of said at least three elbows defines a change in direction of said conductive trace of at least 60 degrees.
4. The security element of claim 2 wherein said first conductive trace and said second conductive trace each comprise four elbows that are rounded and wherein one of said elbows forms a capacitor plate.
5. The security element of claim 4 wherein each of said capacitor plates is approximately 0.2191 square inches.
6. The security tag of claim 4 wherein a ratio of a width of either of said conductive traces to a length of said security tag is at least 1 to 10.
7. The security element of claim 4 wherein each of said four elbows has a radius of curvature of approximately 0.15 inches.
8. The security tag of claim 1 wherein said first and second conductive traces comprise aluminum.
9. The security tag of claim 1 wherein plastic layers comprise:
a first plastic layer adhesively-secured to said first conductive trace;
a second plastic layer adhesively-secured to said second conductive trace; and
wherein said first plastic layer and said second plastic layer each comprise overlap regions that are sealed together.
10. The security tag of claim 1 wherein said first and second conductive traces and said dielectric layer form an electrical circuit that resonates at 8.2 MHz.
11. The security tag of claim 10 wherein said electrical circuit has a quality factor (Q) of approximately 88-90 and provides a detectable response signal strength when said security tag, attached to a food product, is interrogated.
12. The security tag of claim 1 wherein said first and second conductive traces are crimped to form said electrical coupling.
13. The security tag of claim 10 wherein said tag emits a response signal having a power that is approximately 1.7 times the power of a response signal of a security tag having multiple loop conductive traces.
14. The security tag of claim 6 wherein the width of said first conductive trace comprises approximately 0.20 inches.
15. The security tag of claim 6 wherein the width of said second conductive trace comprises approximately 0.26 inches.