An accessory unit for an electronic device comprises: an RF transmitter for transmitting the data signal received from the electronic device; a holder for the electronic device, the RF transmitter being coupled to the holder, the holder having a first connector for connecting with the electronic device; a power acquisition unit coupled with the holder and for receiving the electric energy from the outer power supply; and a second connector for connecting the holder to the power acquisition unit and for radiating the RF signal received from the RF transmitter.