US 2010/0164726 A1 · COMMUNICATION ANTENNA, RFID TAG, NON-CONTACT COMMUNICATION DEVICE, AND NON-CONTACT COMMUNICATION METHOD

Abstract

A communication antenna has a rectangular radiating section, and has a structure that emits an electric field of linear polarized waves only in a vicinity of the radiating section of the antenna. An RFID tag has an IC chip and a tag antenna that is long in a predetermined direction. The tag antenna has a main antenna portion that is rectilinear and extends over substantially an entire length in a longitudinal direction of the tag antenna, and folded-over antenna portions at which currents induced by an external electric field offset one another due to portions that extend in mutually different orientations in the longitudinal direction. A parallel interval between the main antenna portion and a first folded-over antenna portion exceeds a width of the radiating section of the communication antenna.

Claims10

Dependent claims

A communication antenna formed in a flat-plate-shape overall, for carrying out communication with an RFID tag, the communication antenna comprising:

a ground layer formed at one surface of the communication antenna over substantially an entire surface;
and
a rectangular radiating section formed in a rectangular shape at another surface of the communication antenna, and having, at about a central portion in a longitudinal direction of the radiating section, a single feed point that passes through the ground layer,
wherein a width of the radiating section in a direction forming a right angle with the longitudinal direction of the radiating section is greater than or equal to 0.3 mm and less than 10 mm, and
an interval between the radiating section and the ground layer is greater than or equal to 1/512 and less than 1/64 of a wavelength of radio waves used in communication.

2 more elements

An RFID tag comprising:

an element for communication;
and
a tag antenna formed by being folded-over a plurality of times in a longitudinal direction of the tag antenna at both sides in the longitudinal direction so as to be symmetrical with respect to the element for communication, the tag antenna having a main antenna portion extending in a rectilinear form over substantially an entire length in the longitudinal direction, and, at portions extending in mutually different orientations of the longitudinal direction, folded-over antenna portions at which currents induced by an external electric field offset one another, the tag antenna being structured such that the main antenna portion and the folded-over antenna portions are parallel in a transverse direction.

Dependencies are inferred from the claim text.

Communication antenna, rfid tag, non-contact communication device, and non-contact communication method

Life of this patent

Communication antenna, rfid tag, non-contact communication device, and non-contact communication method

Life of this patent

Abstract

Claims10