Modeling and impedance matching for radio frequency driven plasma lamp considering cold and hot states

A new dual-state impedance matching scheme for a microwave driven plasma lamp using a solid-state power amplifier (SSPA) is presented. The impedance of the plasma lamp depends on the amount of input radio frequency (RF) energy, and therefore has very different values for hot and cold states. First, a method for effectively modeling the electrical characteristics of a plasma lamp that depends on RF power has been proposed. Second, a new technique has been proposed to achieve dual-state impedance matching for two state impedances at two very close frequencies using a T-shaped matching network with two section shunt stub and additional transmission line. The proposed method can achieve dual state impedance matching in two frequency bands located very closely when compared to the conventional methods. The accuracy of the proposed model and the effectiveness of the proposed dual-state matching are verified via a plasma lamp system with a 2.45 GHz 300 W GaN SSPA.