A novel single - phase, seven - level inverter with unbalanced coupled inductors is presented in this paper. Only one DC source is required for the proposed inverter and no DC voltage dividers (capacitors) are required. Six Power Electronic (PE) switches form a three - arm power circuit. There must be no DC voltage across the coupled inductors, so switching patterns are very important. Inverter's function in both fundamental frequency switching and PWM switching is simulated and analyzed. According to results, using high frequency switching is inevitable.