An electronic device and an antenna device of an electronic device are provided. The electronic device includes a wafer, a radio frequency integrated circuit (RFIC) fabricated in the wafer, an antenna interposer disposed on a surface of the wafer, an antenna structure fabricated in the antenna interposer, the antenna structure comprising a first conductive pattern with a first electrical length and a second conductive pattern with a second electrical length, a switch formed in the RFIC and electrically connected to at least one of the first conductive pattern or the second conductive pattern based on a frequency band of a signal being transmitted or received by the RFIC, and a through hole formed in at least part of the wafer or the antenna interposer and electrically connecting the RFIC and the antenna structure.