A wireless charging device (102) includes a driver unit (110) configured to generate one of a first AC voltage signal having a first frequency and a second AC voltage signal having a second frequency. Also, the wireless charging device (102) includes a transmitting unit (114) having a first coil (130) and a first capacitor (132) and configured to transmit the first AC voltage signal. Further, the transmitting unit (114) includes a second coil (134) and a second capacitor (136) and configured to transmit the second AC voltage signal. Additionally, the wireless charging device (102) includes a control unit (112) configured to detect a first receiver device (104) operating at the first frequency based on a change in a first voltage in the transmitting unit (114), and detect a second receiver device (106) operating at the second frequency based on a change in a second voltage in the transmitting unit (114).