An electronic device comprising: a housing including a first surface and a second surface facing away from the first surface; a coil antenna (530, 610, 810) disposed within the housing and forming a plurality of loops around an axis substantially perpendicular to at least one of the first and second surfaces, the coil antenna including: a feeding coil forming at least one loop; and a resonance coil forming at least one loop, configured to resonate at a specific frequency, physically separated from the feeding coil, and located proximate to the feeding coil to enable electrical coupling therewith; a communication circuit disposed within the housing, electrically connected to the feeding coil, and configured to output an electrical signal at the specific frequency to the feeding coil, wherein the feeding coil and the resonance coil are so configured that the electrical signal output from the communication circuit to the feeding coil induces an electrical current to flow in the resonance coil that correspondingly generates a magnetic field signal for transmitting an electric signal at the specific frequency to an external device; and a processor disposed within the housing and electrically connected to the communication circuit, wherein the feeding coil is configured to resonate at a frequency higher than the specific frequency at which the resonance coil is configured to resonate. a housing including a first surface and a second surface facing away from the first surface; a coil antenna (530, 610, 810) disposed within the housing and forming a plurality of loops around an axis substantially perpendicular to at least one of the first and second surfaces, the coil antenna including: a feeding coil forming at least one loop; and a resonance coil forming at least one loop, configured to resonate at a specific frequency, physically separated from the feeding coil, and located proximate to the feeding coil to enable electrical coupling therewith; a communication circuit disposed within the housing, electrically connected to the feeding coil, and configured to output an electrical signal at the specific frequency to the feeding coil, wherein the feeding coil and the resonance coil are so configured that the electrical signal output from the communication circuit to the feeding coil induces an electrical current to flow in the resonance coil that correspondingly generates a magnetic field signal for transmitting an electric signal at the specific frequency to an external device; and a processor disposed within the housing and electrically connected to the communication circuit, wherein the feeding coil is configured to resonate at a frequency higher than the specific frequency at which the resonance coil is configured to resonate. a feeding coil forming at least one loop; and a resonance coil forming at least one loop, configured to resonate at a specific frequency, physically separated from the feeding coil, and located proximate to the feeding coil to enable electrical coupling therewith; a communication circuit disposed within the housing, electrically connected to the feeding coil, and configured to output an electrical signal at the specific frequency to the feeding coil, wherein the feeding coil and the resonance coil are so configured that the electrical signal output from the communication circuit to the feeding coil induces an electrical current to flow in the resonance coil that correspondingly generates a magnetic field signal for transmitting an electric signal at the specific frequency to an external device; and a processor disposed within the housing and electrically connected to the communication circuit, wherein the feeding coil is configured to resonate at a frequency higher than the specific frequency at which the resonance coil is configured to resonate.