An RFID tag for use in an RFID card, the RFID tag comprising: an electronic circuit attached to a main antenna body, the main antenna body defining a center through which a first imaginary axis and a second imaginary axis intersect, the first imaginary axis is perpendicular to the second imaginary axis, the main antenna comprising: two opposite side portions, wherein a first of the side portions is substantially symmetrical with a second of the side portions about the second imaginary axis; an elongate first slot that extends from the center of the main antenna body substantially along the second imaginary axis; and a second slot substantially perpendicular to and intersecting the inner portion of the elongate first slot proximate the center of the main antenna body wherein the electronic circuit is attached proximate the intersection of the first and second slots; wherein the RFID tag is characterized in that: each of the side portions extends outwardly from the first imaginary axis along the second imaginary axis to form a generally side-oriented v-shape; and the elongate first slot comprises: a first side slot portion defining a side slot height; a second side slot portion; and an inner slot portion between the first side slot portion and the second side slot portion, the inner slot portion defining an inner portion slot height that is less than the side slot height. an electronic circuit attached to a main antenna body, the main antenna body defining a center through which a first imaginary axis and a second imaginary axis intersect, the first imaginary axis is perpendicular to the second imaginary axis, the main antenna comprising: two opposite side portions, wherein a first of the side portions is substantially symmetrical with a second of the side portions about the second imaginary axis; an elongate first slot that extends from the center of the main antenna body substantially along the second imaginary axis; and a second slot substantially perpendicular to and intersecting the inner portion of the elongate first slot proximate the center of the main antenna body wherein the electronic circuit is attached proximate the intersection of the first and second slots; wherein the RFID tag is characterized in that: two opposite side portions, wherein a first of the side portions is substantially symmetrical with a second of the side portions about the second imaginary axis; an elongate first slot that extends from the center of the main antenna body substantially along the second imaginary axis; and a second slot substantially perpendicular to and intersecting the inner portion of the elongate first slot proximate the center of the main antenna body wherein the electronic circuit is attached proximate the intersection of the first and second slots; a second slot substantially perpendicular to and intersecting the inner portion of the elongate first slot proximate the center of the main antenna body wherein the electronic circuit is attached proximate the intersection of the first and second slots; each of the side portions extends outwardly from the first imaginary axis along the second imaginary axis to form a generally side-oriented v-shape; and the elongate first slot comprises: a first side slot portion defining a side slot height; a second side slot portion; and an inner slot portion between the first side slot portion and the second side slot portion, the inner slot portion defining an inner portion slot height that is less than the side slot height. a first side slot portion defining a side slot height; a second side slot portion; and an inner slot portion between the first side slot portion and the second side slot portion, the inner slot portion defining an inner portion slot height that is less than the side slot height.