Antenna for radio-frequency identification tag

Abstract

An antenna for a radio frequency identification (RFID) tag includes an antenna radiating element and a loop antenna. The antenna radiating element includes a connecting portion, a first meandering radiating element, and a second meandering radiating element. The connecting portion includes a first end and a second end, and the connecting portion has a length direction. The first meandering radiating element extends from the first end of the connecting portion and has a first meandering axis that is not parallel to the length direction. The second meandering radiating element extends from the second end of the connecting portion and has a second meandering axis that is not parallel to the length direction. The loop antenna is located between the first and second meandering radiating elements, and there is no conductive connection between the loop antenna and the antenna radiating element.

Claims

1. An antenna for a radio frequency identification (RFID) tag, comprising: an antenna radiating element, comprising: a connecting portion including a first end and a second end, and the connecting portion having a length direction; a first meandering radiating element extending from the first end of the connecting portion, the first meandering radiating element having a first meandering axis that is not parallel to the length direction, wherein the first meandering radiating element extends substantially laterally along the first meandering axis; and a second meandering radiating element extending from the second end of the connecting portion, the second meandering radiating element having a second meandering axis that is not parallel to the length direction, wherein the second meandering radiating element extends substantially laterally along the second meandering axis; and a loop antenna located between the first meandering radiating element and the second meandering radiating element, wherein there is no conductive connection between the loop antenna and the antenna radiating element.

2. The antenna for a radio frequency identification tag as claimed in claim 1, wherein the first serpentine strip axis and the second serpentine strip axis are substantially perpendicular to the length direction.

3. The antenna for a radio frequency identification tag as claimed in claim 1, wherein the loop antenna includes a first portion adjacent to the connection portion and a second portion away from the connection portion, the second portion including a first open end and a second open end opposite to each other, and the loop antenna does not include any other open ends other than the first and the second open ends.

4. The antenna for a radio frequency identification tag as claimed in claim 1 or 3, wherein the loop antenna further includes a first meandering portion and a second meandering portion opposite to the first meandering portion.

5. The antenna for a radio frequency identification tag as claimed in claim 4, wherein the loop antenna has an axial length substantially parallel to the length direction, and the width of a bend in each of the first bend and the second bend is less than half the axial length of the loop antenna.

6. The antenna of the RFID tag as claimed in claim 5, wherein the axial length is less than a length of the connector.

7. The antenna for a radio frequency identification tag as claimed in claim 4, wherein a swivel axis of the first swivel portion is substantially parallel to the first swivel axis, and a swivel axis of the second swivel portion is substantially parallel to the second swivel axis.

8. The antenna for a radio frequency identification tag as claimed in claim 1, wherein the antenna radiating element further comprises a first radiating block and a second radiating block, the first radiating block extending from one end of the first meandering radiating element, and the second radiating block extending from one end of the second meandering radiating element.

9. The antenna for a radio frequency identification tag as claimed in claim 8, wherein a length direction of the first radiating block and a length direction of the second radiating block are substantially parallel to the length direction of the connecting portion.

10. The antenna for a radio frequency identification tag as claimed in claim 8, wherein the first radiating element and the second radiating element each have a first radiating band width and a second radiating band width, a length of the first radiating block is greater than or equal to the first radiating band width, a length of the second radiating block is greater than or equal to the second radiating band width, and a distance between the first radiating block and the second radiating block is about 1 mm to about 12 mm.

11. The antenna for a radio frequency identification tag as claimed in claim 1, wherein the first meandering radiating element comprises a plurality of alternating and connected first short segments and a plurality of first long segments, one of the first short segments extending from the first end, each of the first short segments not parallel to each of the first long segments, and the number of the first long segments is even; and wherein the second meandering radiating element comprises a plurality of alternating and connected second short segments and a plurality of second long segments, one of the second short segments extending from the second end, each of the second short segments not parallel to each of the second long segments, and the number of the second long segments is even.

12. The antenna for a radio frequency identification tag as claimed in claim 1, wherein the first meandering radiating element and the second meandering radiating element are mirror images of each other.

13. The antenna of the RFID tag as claimed in claim 1, wherein the distance between the loop antenna and the connection portion is about 0.2 mm to about 1 mm.

14. An antenna for a radio frequency identification (RFID) tag, comprising: an antenna radiating element, comprising: a connecting portion including a first end and a second end, and the connecting portion having a length direction; a first meandering radiating element extending from the first end of the connecting portion, the first meandering radiating element having a first meandering axis, the first meandering axis not parallel to the length direction; and a second meandering radiating element extending from the second end of the connecting portion, the second meandering radiating element having a second meandering axis, the second meandering axis not parallel to the length direction; and a loop antenna located between the first meandering radiating element and the second meandering radiating element, and there is no conductive connection between the loop antenna and the antenna radiating element; The antenna radiating element further includes a first radiating block and a second radiating block. The first radiating block extends from one end of the first meandering radiating element, and the second radiating block extends from one end of the second meandering radiating element. The first meandering radiating element and the second meandering radiating element each have a first meandering band width and a second meandering band width, respectively. The length of the first radiating block is greater than or equal to the first meandering band width, and the length of the second radiating block is greater than or equal to the second meandering band width. The distance between the first radiating block and the second radiating block is approximately 1 mm to approximately 12 mm.

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