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

Abstract

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.

Inventors:
 [1]
  1. Gaithersburg, MD
Issue Date:
Research Org.:
Fusion Lighting, Inc., Rockville, MD (United States)
OSTI Identifier:
872322
Patent Number(s):
5910710
Assignee:
Fusion Lighting, Inc. (Rockville, MD)
Patent Classifications (CPCs):
H - ELECTRICITY H05 - ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR H05B - ELECTRIC HEATING
DOE Contract Number:  
FG01-95EE23796
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
method; apparatus; powering; electrodeless; lamp; reduced; radio; frequency; interference; waveguide; structure; tuned; absorbers; spurious; rf; signals; integral; selective; attenuation; resonant; positioned; absorb; out-of-band; energy; negligible; effect; selected; excite; plasma; embodiment; slabs; lossy; magnetic; material; affixed; sidewalls; approximately; quarter; wavelength; signal; wall; positioning; optimizes; absorption; power; conjunction; band; rejection; filter; elements; third; microstrip; couple; embodiments; significantly; diminish; efficiency; selected frequency; electrodeless lamp; third embodiment; filter elements; rf signal; filter element; radio frequency; rf energy; magnetic material; quarter wavelength; waveguide structure; spurious signal; rf signals; energy efficiency; selective attenuation; frequency interference; quarter wave; reduced radio; lamp waveguide; /315/

Citation Formats

Simpson, James E. Method and apparatus for powering an electrodeless lamp with reduced radio frequency interference. United States: N. p., 1999. Web.
Simpson, James E. Method and apparatus for powering an electrodeless lamp with reduced radio frequency interference. United States.
Simpson, James E. Fri . "Method and apparatus for powering an electrodeless lamp with reduced radio frequency interference". United States. https://www.osti.gov/servlets/purl/872322.
@article{osti_872322,
title = {Method and apparatus for powering an electrodeless lamp with reduced radio frequency interference},
author = {Simpson, James E},
abstractNote = {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.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Jan 01 00:00:00 EST 1999},
month = {Fri Jan 01 00:00:00 EST 1999}
}