A transmitting assembly (114, 214, 334) configured to transmit electric power in a universal wireless charging device (102, 200, 302) is presented. The transmitting assembly (114, 214, 334) includes a first coil (116, 216, 316) embedded in a printed circuit board (220) and configured to transmit a first AC voltage signal having a first frequency. Also, the transmitting assembly (114, 214, 334) includes a second coil (118, 218, 318) disposed on the printed circuit board (220) and configured to transmit a second AC voltage signal having a second frequency, wherein the second frequency is different from the first frequency, and wherein the first AC voltage signal having the first frequency and the second AC voltage signal having the second frequency are used to wirelessly charge a plurality of receiver devices (104, 106) having different frequency standards.