Electrodeless high intensity discharge lamp energized by a rotating electric field

摘要

An electrodeless high intensity discharge lamp includes a lamp capsule containing a fill material for emitting radiation upon excitation by high frequency electromagnetic energy, a plurality of applicators spaced around a lamp capsule for nonresonant coupling of high frequency energy to the lamp capsule, a high frequency source for supplying high frequency power, and a power splitter and phase shifter for coupling high frequency power from the source to the applicators such that an electric field applied to the lamp capsule rotates at the frequency of the source. The applied high frequency energy is distributed over the lamp capsule so that the tendency for lamp envelope hot spots is reduced. Preferably, four helical couplers are spaced at 90° intervals around the lamp capsule. The high frequency power applied to adjacent applicators is shifted in phase by 90°.