In this thesis, a single-stage electronic ballast with a high power factor feature for driving HID lamps is proposed. A new frequency-modulation technique is proposed to eliminate the acoustic resonance problem in HID lamps under high frequency operation. The proposed method has the merits of simple circuit and low cost, thus it is suitable for commercial applications. The operating principles and design considerations of the proposed electronic ballast are analyzed and discussed in detail. A 35W laboratory prototype is designed and implemented. The simulation and experimental waveforms are given to verify the feasibility of the proposed method. The results are satisfactory.