A built-in antenna for an electronic device, the antenna comprising: a substrate having a conductive area and a non-conductive area; a 1st antenna radiator with at least a first radiating portion and a second radiating portion arranged within the non-conductive area of the substrate, wherein the 1st antenna radiator is fed by an Radio Frequency, RF, end of the substrate and is connected to the conductive area; a 2nd antenna radiator comprising two main portions that run parallel to the second radiation portion, the 2nd antenna radiator being configured to operate at a band different from an operating band of the at least first radiating portion and second radiating portion of the 1st antenna radiator, and fed by the RF end in a position adjacent to the 1st antenna radiator; wherein the first radiation portion is formed in an L-shape connected to a U-shape and the second radiation portion is formed in a straight line parallel to an end portion of the U-shape, wherein the main portions of the 2nd antenna radiator are arranged in a position to achieve coupling with at least second radiating portion of the 1st antenna radiator; and a switching means switching to selectively feed the 1st antenna radiator and the 2nd antenna radiator, wherein, when the 1st antenna radiator is connected to the RF end by the switching means, the 2nd antenna radiator is electromagnetically coupled with the 1st antenna radiator and is used as a floating dummy pattern, wherein the coupling is sufficient to expand an operating bandwidth of the 1st antenna radiator, wherein when the 1st antenna radiator is disconnected to the RF end by the switching means, only the 2nd antenna radiator is operated. a substrate having a conductive area and a non-conductive area; a 1st antenna radiator with at least a first radiating portion and a second radiating portion arranged within the non-conductive area of the substrate, wherein the 1st antenna radiator is fed by an Radio Frequency, RF, end of the substrate and is connected to the conductive area; a 2nd antenna radiator comprising two main portions that run parallel to the second radiation portion, the 2nd antenna radiator being configured to operate at a band different from an operating band of the at least first radiating portion and second radiating portion of the 1st antenna radiator, and fed by the RF end in a position adjacent to the 1st antenna radiator; wherein the first radiation portion is formed in an L-shape connected to a U-shape and the second radiation portion is formed in a straight line parallel to an end portion of the U-shape, wherein the main portions of the 2nd antenna radiator are arranged in a position to achieve coupling with at least second radiating portion of the 1st antenna radiator; and a switching means switching to selectively feed the 1st antenna radiator and the 2nd antenna radiator, wherein, when the 1st antenna radiator is connected to the RF end by the switching means, the 2nd antenna radiator is electromagnetically coupled with the 1st antenna radiator and is used as a floating dummy pattern, wherein the coupling is sufficient to expand an operating bandwidth of the 1st antenna radiator, wherein when the 1st antenna radiator is disconnected to the RF end by the switching means, only the 2nd antenna radiator is operated.