The disclosure relates to a communication technique for merging an IoT technology with a 5th Generation (5G) communication system for supporting a higher data transmission rate than a 4th Generation (4G) system, and a system therefor. The disclosure can be applied to intelligent services (for example, smart homes, smart buildings, smart cities, smart cars or connected cars, healthcare, digital education, retail, security- and safety-related services, and the like) on the basis of 5G communication technologies and IoT-related technologies. An electronic device is provided. The electronic device includes a board, a plurality of antenna arrays arranged on the board, and a plurality of floating radiator arrays arranged on the board to be spaced apart from the plurality of antenna arrays by a predetermined distance. The plurality of floating radiator arrays are electromagnetically coupled to the plurality of antenna arrays.