Investigation on efficacy optimization of RF-driven automotive D-lamps

Investigations on driving high-intensity discharge xenon lamps with a 2.45GHz signal show an increase of the efficacy. These lamps are used as automotive headlights, because of their high efficacy and their high luminance. The RF-signal also enables the usage of several optimizing features such as amplitude modulation. By enabling an amplitude modulated envelope an efficacy increase of 17% is measured. The investigation of the optimization of the efficacy is presented using a switched DC lamp, compact coaxial lamp and low loss waveguide and verify the improvement. The results are further analyzed using a photo diode to measure the influence of the modulation.