A power supply device for an internal antenna of a display is provided. The power supply device includes at least two coils configured to be separated by a predetermined interval and a power supply terminal of the at least two coils to connect the at least two coils in parallel. An integrated circuit (IC) includes the power supply terminal of the at least two coils connects the at least two coils in parallel and supplies a current to the at least two coils through the included power supply terminal. Phases of the current flowing in the at least two coils are the same due to the current supplied by the IC.