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Title: Method and apparatus for powering an electrodeless lamp with reduced radio frequency interference

Patent ·
OSTI ID:6457855

An electrodeless lamp waveguide structure includes tuned absorbers for spurious RF signals. A lamp waveguide with an integral frequency selective attenuation includes resonant absorbers positioned within the waveguide to absorb spurious out-of-band RF energy. The absorbers have a negligible effect on energy at the selected frequency used to excite plasma in the lamp. In a first embodiment, one or more thin slabs of lossy magnetic material are affixed to the sidewalls of the waveguide at approximately one quarter wavelength of the spurious signal from an end wall of the waveguide. The positioning of the lossy material optimizes absorption of power from the spurious signal. In a second embodiment, one or more thin slabs of lossy magnetic material are used in conjunction with band rejection waveguide filter elements. In a third embodiment, one or more microstrip filter elements are tuned to the frequency of the spurious signal and positioned within the waveguide to couple and absorb the spurious signal's energy. All three embodiments absorb negligible energy at the selected frequency and so do not significantly diminish the energy efficiency of the lamp. 18 figs.

Sponsoring Organization:
USDOE; USDOE, Washington, DC (United States)
DOE Contract Number:
FG01-95EE23796
Assignee:
Fusion Lighting, Inc., Rockville, MD (United States)
Patent Number(s):
US 5910710; A
Application Number:
PPN: US 8-754858
OSTI ID:
6457855
Resource Relation:
Patent File Date: 22 Nov 1996
Country of Publication:
United States
Language:
English