An electronic device , comprising: a frame structure , wherein the frame structure comprises: an outer metallic portion comprising a first metallic material and forming at least a portion of an outer surface of the electronic device ; an inner metallic portion comprising a second metallic material different from the first metallic material and laterally surrounded by the outer metallic portion ; and a first inner polymeric portion isolated from the inner metallic portion and at least partially laterally surrounded by the outer metallic portion ; an organic layer between the outer metallic portion and the first inner polymeric portion ; a metallic layer that comprises a third metallic material different from the first and second metallic materials and is interposed between the outer metallic portion and the inner metallic portion ; and wherein the outer metallic portion further comprises a portion that is disposed between the inner metallic portion and the first inner polymeric portion and physically isolates the inner metallic portion and the first inner polymeric portion ; and wherein the electronic device comprises a wireless communication circuit electrically connected to a portion of the outer metallic portion . a frame structure , wherein the frame structure comprises: an outer metallic portion comprising a first metallic material and forming at least a portion of an outer surface of the electronic device ; an inner metallic portion comprising a second metallic material different from the first metallic material and laterally surrounded by the outer metallic portion ; and a first inner polymeric portion isolated from the inner metallic portion and at least partially laterally surrounded by the outer metallic portion ; an organic layer between the outer metallic portion and the first inner polymeric portion ; a metallic layer that comprises a third metallic material different from the first and second metallic materials and is interposed between the outer metallic portion and the inner metallic portion ; and wherein the outer metallic portion further comprises a portion that is disposed between the inner metallic portion and the first inner polymeric portion and physically isolates the inner metallic portion and the first inner polymeric portion ; and wherein the electronic device comprises a wireless communication circuit electrically connected to a portion of the outer metallic portion . an outer metallic portion comprising a first metallic material and forming at least a portion of an outer surface of the electronic device ; an inner metallic portion comprising a second metallic material different from the first metallic material and laterally surrounded by the outer metallic portion ; and a first inner polymeric portion isolated from the inner metallic portion and at least partially laterally surrounded by the outer metallic portion ; an organic layer between the outer metallic portion and the first inner polymeric portion ; a metallic layer that comprises a third metallic material different from the first and second metallic materials and is interposed between the outer metallic portion and the inner metallic portion ; and wherein the outer metallic portion further comprises a portion that is disposed between the inner metallic portion and the first inner polymeric portion and physically isolates the inner metallic portion and the first inner polymeric portion ; and wherein the electronic device comprises a wireless communication circuit electrically connected to a portion of the outer metallic portion . <EOS>