An electronic device includes a housing including a front plate and a rear plate disposed opposite the front plate, and a display disposed in a space between the front plate and the rear plate, and disposed at least partially along the front plate. The electronic device further includes a first antenna structure disposed in the space and configured to transmit or receive a first signal in a first frequency band, wherein the first antenna structure includes at least one first conductive pattern. The electronic device also includes a second antenna structure disposed in the space without being overlapped with the first conductive pattern when viewed from above the rear plate, and configured to transmit or receive a second signal in a second frequency band different from the first frequency band. In addition, the electronic device includes a conductive sheet disposed in the space and on the rear plate. The conductive sheet is physically separated from the first conductive pattern, and at least partially overlapped with the first conductive pattern when viewed from above the rear plate.