Patent Abstract:
A plasma lamp apparatus includes a post structure with a material overlying a surface region of the post structure, which has a first end and a second end. The apparatus also has a helical coil structure configured along the post structure. The apparatus includes a bulb with a fill material capable of emitting electromagnetic radiation. A resonator coupling element configured to feed radio frequency energy to at least the helical coil causes the bulb device to emit electromagnetic radiation.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority from provisional patent application Ser. No. 61/185,556, filed Jun. 9, 2009, entitled Helical Structure and Method for Plasma Lamp, which is incorporated by reference herein for all purposes. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to lighting techniques. In particular, the invention provides a method and device using a plasma lighting device having a shaped resonator assembly including a helical or coil structure, which is coupled to a radio frequency source. Such plasma lamps can be applied to applications such as stadiums, security, parking lots, military and defense, streets, large and small buildings, vehicle headlamps, aircraft landing, bridges, warehouses, uv water treatment, agriculture, architectural lighting, stage lighting, medical illumination, microscopes, projectors and displays, and similar uses. 
     From the early days, human beings have used a variety of techniques for lighting. Early humans relied on fire to light caves during hours of darkness. Fire often consumed wood for fuel. Wood fuel was soon replaced by candles, which were derived from oils and fats. Candles were then replaced, at least in part by lamps. Certain lamps were fueled by oil or other sources of energy. Gas lamps were popular and still remain important for outdoor activities such as camping. In the late 1800, Thomas Edison, who is one of the greatest inventors of all time, conceived the incandescent lamp, which uses a tungsten filament within a bulb, coupled to a pair of electrodes. Many conventional buildings and homes still use the incandescent lamp, commonly called the Edison bulb. Although highly successful, the Edison bulb consumed much energy and was generally inefficient. 
     Fluorescent lighting has replaced incandescent lamps for certain applications. Fluorescent lamps generally consist of a tube containing a gaseous material, which is coupled to a pair of electrodes. The electrodes are coupled to an electronic ballast, which helps ignite the discharge from the fluorescent lighting. Conventional building structures often use fluorescent lighting, rather than the incandescent counterpart. Fluorescent lighting is much more efficient than incandescent lighting, but often has a higher initial cost. 
     Shuji Nakamura pioneered the efficient blue light emitting diode, which is a solid state lamp. The blue light emitting diode forms a basis for the white solid state light, which is often a blue light emitting diode within a bulb coated with a yellow phosphor material. Blue light excites the phosphor material to emit white light. The blue light emitting diode has revolutionized the lighting industry to replace traditional lighting for homes, buildings, and other structures. 
     Another form of lighting is commonly called the electrodeless lamp, which can be used to discharge light for high intensity applications. Frederick M. Espiau was one of the pioneers that developed an improved electrodeless lamp. Such electrodeless lamp relied upon a solid ceramic resonator structure, which was coupled to a fill enclosed in a bulb. The dielectric resonator (dielectric waveguide) coupled the RF energy from an RF source to the bulb fill to cause it to discharge high intensity lighting. Although somewhat successful, the electrodeless lamp still had many limitations. The dielectric material (such as Alumina) used for the dielectric resonator/waveguide must have low losses at RF frequencies resulting in higher material cost. Furthermore, the dielectric resonator/waveguide is difficult to manufacture resulting in an expensive lamp. As an example, electrodeless lamps have not been successfully deployed in high volume for general lighting applications. Additionally, electrodeless lamps are generally difficult to disassemble and assembly leading to inefficient use of such lamps. These and other limitations may be described throughout the present specification and more particularly below. 
     From the above, it is seen that improved techniques for lighting are highly desired. 
     BRIEF SUMMARY OF THE INVENTION 
     According to the present invention, techniques for lighting are provided. In particular, the present invention provides a method and device using an electrodeless plasma lighting device having a shaped resonator assembly including a helical or coil structure, which is coupled to a radio frequency source. Such plasma lamps can be applied to applications such as stadiums, security, parking lots, military and defense, streets, large and small buildings, vehicle headlamps, aircraft landing, bridges, warehouses, uv water treatment, agriculture, architectural lighting, stage lighting, medical illumination, microscopes, projectors and displays, any combination of these, and the like. 
     In a specific embodiment, the present invention provides a plasma lamp apparatus. The apparatus includes a post structure comprising a material overlying a surface region of the post structure, which has a first end and a second end. The apparatus also has a helical coil structure operably configured along one or more portions of the post structure according to a specific embodiment. In a preferred embodiment, the helical coil acts as an inductive coupling structure and also facilitates thermal energy transport. The apparatus has a bulb device configured to the first end of the post structure, which is coupled to the helical coil structure. In a preferred embodiment, the bulb device comprises a gas filled vessel that is filled with an inert gas such as Argon and a fluorophor or light emitter such as Mercury, Sodium, Dysprosium, Sulfur or a metal halide salt such as Indium Bromide, Scandium Bromide, or Cesium Iodide (or it can simultaneously contain multiple fluorophors or light emitters). The gas filled vessel can also include a metal halide, or other metal pieces that will discharge electromagnetic radiation according to a specific embodiment. The device has a resonator coupling element configured to feed radio frequency energy to at least the helical coil structure and to cause the bulb device to emit electromagnetic radiation. In a specific embodiment, the radio frequency energy has a frequency ranging from 1000 MHz to less than about 8 MHz, but can be others. As used herein, the terms “first” and “second” are not intended to imply order and should be interpreted by ordinary meaning. Additionally, such terms may be defined by at least the descriptions provided in the specification as well as by meanings consistent with one of ordinary skill in the art. 
     In an alternate embodiment of the present invention, a method for lowering the resonant frequency and improving the heat transfer characteristics of the device is created. The method includes creating a helical shaped RF output coupling-element that is either wrapped around a dielectric material, or simply coiled through air. The presence of a dielectric medium within the helical shaped RF output coupling-element serves to more efficiently absorb thermal energy that is generated by the bulb and subsequently transferred through the RF output coupling-element and the dielectric material. In creating a helical shaped RF output coupling element, the inductance of the resonant structure is increased leading to lower resonant frequencies at which the device operates at without substantially changing the size of the resonant structure. In lowering the operational resonant frequency, amplifiers with higher efficiencies can be used to operate the lamp. Alternatively the lower frequency resonator can be used to couple RF energy to larger bulbs and in conjunction with higher power amplifiers, higher lumens output lamps can be realized. Adding a dielectric material within the helical shaped RF output coupling element, helps in transferring the heat from the bulb to the resonator/lamp body. 
     Still further, the present invention provides an apparatus for a plasma lamp. The apparatus includes a gas filled vessel. The apparatus also includes a first coil structure comprising a first end and a second end. Preferably, the first end is coupled to the gas filled vessel. The apparatus also includes a second coil structure, which is coupled with one or more portions of the first coil structure. 
     Moreover, the present invention provides an alternative plasma lamp apparatus. The apparatus has a support structure having a first end and a second end and a coil structure configured along one or more portions of the support structure according to a specific embodiment. The apparatus also has a bulb device configured to the first end of the support structure according to a specific embodiment. The apparatus has a ground potential coupled to the second end of the support structure and a coupling element configured to feed at least radio frequency energy to at least the coil structure and to cause the bulb device to emit electromagnetic radiation. Still further, the present invention provides a method of improving heat transfer of an electrode-less plasma lamp according to an alternative embodiment. The method includes using a helical shaped element to draw thermal energy from a plasma lamp to a thermal sink region in a specific embodiment. 
     Benefits are achieved over pre-existing techniques using the present invention. In a specific embodiment, the present invention provides a method and device having configurations of input, output, and feedback coupling elements that provide for electromagnetic coupling to the bulb whose power transfer and frequency resonance characteristics that are largely independent of the conventional dielectric resonator, but can also be dependent upon conventional designs. In a preferred embodiment, the present invention provides a method and configurations with an arrangement that provides for improved manufacturability as well as design flexibility. Other embodiments may include integrated assemblies of the output coupling element and bulb that function in a complementary manner with the present coupling element configurations and related methods for street lighting applications. Still further, the present method and device provide for improved heat transfer characteristics, as well as further simplifying manufacturing and/or retrofitting of existing and new street lighting, such as lamps, and the like. In a specific embodiment, the present method and resulting structure are relatively simple and cost effective to manufacture for commercial applications. In a specific embodiment, the present invention includes a helical resonator structure, which increases inductance and therefore reduces the resonating frequency of a device. In a preferred embodiment, the resonating frequency may be about 250 MHz and less or about 100 MHz and less depending upon the type of coil, number of windings, and other parameters. In a specific embodiment, the present method and lamp device has a substantially exposed arc, in contrast to conventional plasma lamps where the arc of the bulb is substantially surrounded by the dielectric resonator/waveguide limiting the ability of the lamp to be used with typical luminaries. Depending upon the embodiment, one or more of these benefits may be achieved. These and other benefits may be described throughout the present specification and more particularly below. 
     The present invention achieves these benefits and others in the context of known process technology. However, a further understanding of the nature and advantages of the present invention may be realized by reference to the latter portions of the specification and attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a generalized schematic of a gas-filled vessel capacitively coupled to an RF source. 
         FIG. 1B  is a generalized schematic of a gas-filled vessel inductively coupled to an RF source. 
         FIG. 2A  is a simplified perspective view of an external resonator electrodeless lamp, including an RF amplifier. 
         FIG. 2B  is a simplified perspective view of an alternate external resonator electrodeless lamp, including an RF source. 
         FIG. 2C  is a simplified perspective view of an alternate external resonator electrodeless lamp. 
         FIG. 3A  is a simplified perspective view of an integrated bulb/output coupling-element without a top coupling-element. 
         FIG. 3B  is a simplified side-cut view of the integrated bulb/output coupling-element assembly shown in  FIG. 3A . 
         FIG. 3C  is a simplified perspective view of an alternate integrated bulb/output coupling-element assembly to the one shown in  FIG. 3A . 
         FIG. 3D  is a simplified side-cut view of the alternate integrated bulb/output coupling element assembly shown in  FIG. 3C . 
         FIG. 4A  is a simplified perspective view of an alternate integrated bulb/output coupling-element that is helically shaped in structure and encompasses air according to an embodiment of the present invention. 
         FIG. 4B  is a simplified perspective view of an alternate integrated bulb/output coupling-element that is helically shaped in structure and encompasses a dielectric material with a metal insert that allows for the tuning of the resonance frequency according to an embodiment of the present invention. 
         FIG. 5A  is a simplified cross section of a coil electrodeless lamp where the output support structure that contains the gas-filled vessel is separated from a grounded support structure by a single metal coil element according to an embodiment of the present invention. It is coupled to a resonator coupling element that is straight and adjacent to the output support structure. 
         FIG. 5B  is a simplified cross section of a coil electrodeless lamp where the output support structure that contains the gas-filled vessel is separated from the grounded support structure by a metal coil element wound tightly to a non-conductive support structure according to an embodiment of the present invention. It is coupled to a resonator coupling element that is straight and adjacent to the output support structure. 
         FIG. 5C  is a simplified cross section of a coil electrodeless lamp where the output support structure that contains the gas-filled vessel is separated from the grounded support structure by a metal coil element wound around but not touching a non-conductive support structure according to an embodiment of the present invention. It is coupled to a resonator coupling element that is straight and adjacent to the output support structure. 
         FIG. 5D  is a simplified cross section of a coil electrodeless lamp where the output support structure that contains the gas-filled vessel is separated from the grounded support structure by a spiral coil strips attached or painted around a non-conductive support structure according to an embodiment of the present invention. It is coupled to a resonator coupling element that is straight and adjacent to the output support structure. 
         FIG. 6A  is a simplified cross section of a coil electrodeless lamp where the output support structure that contains the gas-filled vessel is separated from a grounded support structure by a single metal coil element. It is coupled to a resonator coupling element that is a second coil that surrounds the first coil element according to an embodiment of the present invention. 
         FIG. 6B  is a simplified cross section of a coil electrodeless lamp where the output support structure that contains the gas-filled vessel is separated from the grounded support structure by a metal coil element wound tightly to a non-conductive support structure. It is coupled to a resonator coupling element that is a second coil that surrounds the first coil element according to an embodiment of the present invention. 
         FIG. 6C  is a simplified cross section of a coil electrodeless lamp where the output support structure that contains the gas-filled vessel is separated from the grounded support structure by a metal coil element wound around but not touching a non-conductive support structure. It is coupled to a resonator coupling element that is a second coil that surrounds the first coil element according to an embodiment of the present invention. 
         FIG. 6D  is a simplified cross section of a coil electrodeless lamp where the output support structure that contains the gas-filled vessel is separated from the grounded support structure by a spiral coil strips attached or painted around a non-conductive support structure. It is coupled to a resonator coupling element that is a coil that surrounds the spiral coil strips according to an embodiment of the present invention. 
         FIG. 7A  is a simplified cross section of a coil electrodeless lamp where the resonator coupling element is a coil and is separated by a gap from the output support structure according to an embodiment of the present invention. The output support structure can be any embodiment of the structures described in the preceding figures or it can be a straight metal structure that is grounded on one side. 
         FIG. 7B  is a simplified cross section of a coil electrodeless lamp where the resonator coupling element is a coil and is a separated by a gap from the output support structure that is also in the from of a coil according to an embodiment of the present invention. 
         FIG. 8  is a simplified cross section of a coil electrodeless lamp where the output support structure that contains the gas-filled vessel is separated from a grounded support structure by a single metal coil element. It is coupled to a resonator coupling element that is a second coil that surrounds the first coil element. The second coil is fed from the side of the resonator body according to an embodiment of the present invention. 
         FIG. 9  is a simplified cross section of a coil electrodeless lamp where the output support structure that contains the gas-filled vessel is separated from a grounded support structure by a single metal coil element. It is coupled to a resonator couple element that is straight and adjacent to the output support structure. There is an adjustable metal insert within the coil output support structure that travels along the axis of the coil that allows for adjustment of the operating frequency of the resonator according to an embodiment of the present invention. 
         FIG. 10  is a simplified cross section of a coil electrodeless lamp where the output support structure that contains the gas-filled vessel is connected to the grounded support structure by a dielectric post as well as connected to the grounded support structure through the metal coil according to an embodiment of the present invention. It is coupled to a resonator coupling element that is a second coil that surrounds the first coil element. 
         FIG. 11  is a simplified cross section of a coil electrodeless lamp similar to  FIG. 5A  except that the top section of the resonator around the output support structure is filled with a dielectric material to further lower the resonant frequency of the resonator according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     According to the present invention, techniques for lighting are provided. In particular, the present invention provides a method and device using a plasma lighting device having a shaped resonator assembly including a helical or coil structure, which is coupled to a radio frequency source. Merely by way of example, such plasma lamps can be applied to applications such as stadiums, security, parking lots, military and defense, streets, large and small buildings, vehicle headlamps, aircraft landing, bridges, warehouses, uv water treatment, agriculture, architectural lighting, stage lighting, medical illumination, microscopes, projectors and displays, any combination of these, and the like. 
       FIG. 1A  illustrates a general schematic for efficient energy transfer from an RF source  111  to gas fill vessel  130 . This diagram as well as all of the other diagrams are intended to be illustrative of one implementation, which should not unduly limit the scope of the claims herein. One of ordinary skill in the art will recognize other variations, modifications, and alternatives. Energy from the RF source is directed to an impedance matching network  215  that enables the effective transfer of energy from RF source to resonating structure  220 . An example of such impedance matching network is an E-field or H-field coupling element, but can be others. Another impedance matching network  230 , in turn, enables efficient energy transfer from resonator to gas filled vessel  130  according to an embodiment of the present invention. An example of the impedance matching network is an E-field or H-field coupling element Of course, there can be other variations, modifications, and alternatives. 
     In a specific embodiment, the gas filled vessel is made of a suitable material such as quartz or other transparent or translucent material. The gas filled vessel is filled with an inert gas such as Argon and a fluorophor or light emitter such as Mercury, Sodium, Dysprosium, Sulfur or a metal halide salt such as Indium Bromide, Scandium Bromide, or Cesium Iodide (or it can simultaneously contain multiple fluorophors or light emitters). The gas filled vessel can also include a metal halide, or other metal pieces that will discharge electromagnetic radiation according to a specific embodiment. Of course, there can be other variations, modifications, and alternatives. 
     In a specific embodiment, a capacitive coupling structure  131  is used to deliver RF energy to the gas fill within the bulb  130 . As is well known, a capacitive coupler typically comprises two electrodes of finite extent enclosing a volume and couples energy primarily using at least Electric fields (E-fields). As can be appreciated by one of ordinary skill in the art, the impedance matching networks  215  and  230  and the resonating structure  220 , as depicted in schematic form here, can be interpreted as equivalent-circuit models of the distributed electromagnetic coupling between the RF source and the capacitive coupling structure. The use of impedance matching networks also allows the source to have an impedance other than 50 ohms; this may provide an advantage with respect to RF source performance in the form of reduced heating or power consumption from the RF source. Lowering power consumption and losses from the RF source would enable a greater efficiency for the lamp as a whole. As can also be appreciated by one of ordinary skill in the art, the impedance matching networks  215  and  230  are not necessarily identical. 
       FIG. 1B  illustrates a general schematic for efficient energy transfer from an RF source  111  to gas filled vessel  130 . Energy from the RF source is directed to an impedance matching network  215  that enables the effective transfer of energy from RF source to resonating structure  220 . Another impedance matching network  230 , in turn, enables efficient energy transfer from the resonator to gas filled vessel  130 . An inductive coupling structure  145  is used to deliver RF energy to the gas fill within the bulb  130 . As is well known, an inductive coupler typically comprises a wire or a coil-like wire of finite extent and couples energy primarily using magnetic fields (H-fields). As can be appreciated by one of ordinary skill in the art, the impedance matching networks  215  and  230  and the resonating structure  220 , as depicted in schematic form here, can be interpreted as equivalent-circuit models of the distributed electromagnetic coupling between the RF source and the inductive coupling structure. The use of impedance matching networks also allows the source to have an impedance other than 50 ohm; this may provide an advantage with respect to RF source performance in the form of reduced heating or power consumption from the RF source. Lowering power consumption and losses from the RF source would enable a greater efficiency for the lamp as a whole. As can also be appreciated by one of ordinary skill in the art, the impedance matching networks  215  and  230  are not necessarily identical. 
       FIG. 2A  is a simplified perspective view of an electrodeless lamp, employing a lamp body  600 , whose outer surface  601  is electrically conductive and is connected to ground. A cylindrical lamp body is depicted, but rectangular or other shapes may be used. This conductivity may be achieved through the application of a conductive veneer, or through the choice of a conductive material. An example embodiment of conductive veneer is silver paint or alternatively the lamp body can be made from sheet of electrically conductive material such as aluminum. An integrated bulb/output coupling-element assembly  100  is closely received by the lamp body  600  through opening  610 . The bulb/output coupling-element assembly  100  contains the bulb  130 , which is a gas-filled vessel that ultimately produces the luminous output. 
     One aspect of the invention is that the bottom of the assembly  100 , output coupling-element  120 , is grounded to the body  600  and its conductive surface  601  at plane  101 . The luminous output from the bulb is collected and directed by an external reflector  670 , which is either electrically conductive or if it is made from a dielectric material has an electrically conductive backing, and which is attached to and in electrical contact with the body  600 . Another aspect of the invention is that the top of the assembly  100 , top coupling-element  125 , is grounded to the body  600  at plane  102  via the ground strap  710  and the reflector  670 . Alternatively, the reflector  670  may not exist, and the ground strap makes direct electrical contact with the body  600 . Reflector  670  is depicted as parabolic in shape with bulb  130  positioned near its focus. Those of ordinary skill in the art will recognize that a wide variety of possible reflector shapes can be designed to satisfy beam-direction requirements. In a specific embodiment, the shapes can be conical, convex, concave, trapezoidal, pyramidal, or any combination of these, and the like. The shorter feedback E-field coupling-element  635  couples a small amount of RF energy from the bulb/output coupling-element assembly  100  and provides feedback to the RF amplifier input  211  of RF amplifier  210 . Feedback coupling-element  635  is closely received by the lamp body  600  through opening  612 , and as such is not in direct DC electrical contact with the conductive surface  601  of the lamp body. The input coupling-element  630  is conductively connected with RF amplifier output  212 . Input coupling-element  630  is closely received by the lamp body  600  through opening  611 , and as such is not in direct DC electrical contact with the conductive surface  601  of the lamp body. However, it is another key aspect of the invention that the top of the input coupling-element is grounded to the body  600  and its conductive surface  601  at plane  631 . 
     RF power is primarily inductively coupled strongly from the input coupling-element  630  to the bulb/output coupling-element assembly  100  through physical proximity, their relative lengths, and the relative arrangement of their ground planes. Surface  637  of bulb/output coupling-element assembly is covered with an electrically conductive veneer or an electrically conductive material and is connected to the body  600  and its conductive surface  601 . Alternatively it can integrated as part of the lamp body  600 . The other surfaces of the bulb/output coupling-element assembly including surfaces  638 ,  639 , and  640  are not covered with a conductive layer. In addition surface  640  is optically transparent or translucent. The coupling between input coupling-element  630  and output coupling-element  120  and lamp assembly  100  is found through electromagnetic simulation, and through direct measurement, to be highly frequency selective and to be primarily inductive. This frequency selectivity provides for a resonant oscillator in the circuit comprising the input coupling-element  630 , the bulb/output coupling-element assembly  100 , the feedback coupling-element  635 , and the amplifier  210 . 
     One of ordinary skill in the art will recognize that the resonant oscillator is the equivalent of the RF source  111  depicted schematically in  FIG. 1A  and  FIG. 1B . A significant advantage of the invention is that the input coupling-element  630  and the bulb/output coupling-element assembly  100  are respectively grounded at planes  631  and  101 , which are coincident with the outer surface of the body  600 . This eliminates the need to fine-tune their depth of insertion into the lamp body—as well as any sensitivity of the RF coupling between them to that depth—simplifying lamp manufacture, as well as improving consistency in lamp brightness yield. 
       FIG. 2B  is a simplified perspective view of an electrodeless lamp that differs from that shown in  FIG. 2A  only in its RF source, which is not a distributed oscillator circuit, but rather a separate oscillator  205  conductively connected with RF amplifier input  211  of the RF amplifier  210 . RF amplifier output  212  is conductively connected with input coupling-element  630 , which delivers RF power to the lamp/output coupling-element assembly  100 . The resonant characteristics of the coupling between the input coupling-element  630  and the output coupling-element in the bulb/output coupling-element assembly  100  are frequency-matched to the RF source to optimize RF power transfer. Of course, there can be other variations, modifications, and alternatives. 
       FIG. 2C  is a simplified perspective view of an electrode-less lamp that is similar to the electrode-less lamp shown in  FIG. 2A  except that it does not have a reflector  670 . The top coupling-element  125  in the bulb assembly is directly connected to the lamp body  600  using ground straps  715 . This diagram is merely an example, which should not unduly limit the scope of the claims herein. One of ordinary skill in the art would recognize other variations, modifications, and alternatives. 
       FIG. 3A  is a simplified perspective view of an alternative design for an integrated bulb/output coupling-element assembly  100 . The assembly does not contain a top coupling-element. The assembly consists of two sections. The bottom section  110  contains the output coupling-element  120  which consists of a dielectric post  122  made from a material such as alumina with its outer surface coated with a conductive veneer such as silver. The top section consists of the bulb (gas-fill vessel)  130  which is made from a material that is transparent to visible light such as quartz or translucent alumina. It is a key aspect of the invention that dielectric post of the output coupling-element  120  is bored to closely receive bulb  130 , such that heat transfer through its dielectric center and RF coupling through its conductive outer coating take place simultaneously. The area of the dielectric post of the output coupling-element that come in contact with the bulb is not covered with a conductive veneer. Using this bulb assembly approach the high RF fields is kept away from the end of bulb resulting in a more reliable lamp. It is also a key aspect of this invention that output coupling-element  120  makes ground contact at plane  121  with the lamp body  600  depicted in  FIGS. 2A ,  2 B, and  2 C. 
     The portion of body  110  that is received by the lamp body  600  as depicted in  FIGS. 2A ,  2 B, and  2 C (and overlaps with the length of input coupling-element  630 ) and is shown in  FIG. 3A  as being below the dashed line  140 ; is not coated with a conductive layer. The portion of body  110  that is above the lamp body  600  but substantially below the bulb  130  is depicted schematically as the area between  140  and  141 ; this portion may be coated with a conductive veneer  117 . The purpose of the conductive coatings is to shield against unwanted electromagnetic radiation. An example embodiment of conductive veneer  117  is silver paint. Alternatively, instead of a conductive veneer, portion of the body  110  between  140  and  141  can be covered by a metal ring  650  as part of the extension of the lamp body  600 . 
       FIG. 3B  is a simplified side-cut view of an integrated bulb/output coupling-element assembly  100  shown in  FIG. 3A . 
       FIG. 3C  is a perspective view of an alternative design for an integrated bulb/output coupling-element assembly  100  which is the same as the output support structure depicted in  FIG. 7A . The assembly is made using a solid conductor (metal post)  120  and is recessed at the top to closely receive one end of the gas-filled vessel  130 . The other end of metal post  121  is grounded to the lamp body. A thin layer of dielectric material or refractory metal such as molybdenum can be used as interface between the bulb and the metal post. Alternatively the top part of the metal post or all of the metal post can be made from a refractory metal with its outer surface covered with a layer of metal with high electrical conductivity such as silver or copper. The metal post can also be hollow inside or filled with a different metal with higher thermal conductivity. The assembly has no top coupling element. 
       FIG. 3D  is a side-cut view of an integrated bulb/output coupling-element assembly  100  shown in  FIG. 3C . The bulb/output coupling-element is similar to  FIG. 3B  except the post is made from a solid conductor instead of a dielectric material covered with conductive layer. This diagram is merely an example, which should not unduly limit the scope of the claims herein. One of ordinary skill in the art would recognize other variations, modifications, and alternatives. 
       FIG. 4A  is a simplified perspective view of an embodiment of the present invention including an RF output coupling-element that is helical in structure and encompasses air. The helical structure  507  can have anywhere from 2 to 30 windings. In other embodiments, the windings can be more than one winding, including portions, and may be greater than thirty windings. In still other embodiments, the windings can be a portion of one winding. The output coupling-element includes a conductive metal and is attached to the metal post structure  505  that holds the bulb  130  in place. The metal used in the output coupling-element can be but is not limited to aluminum, brass, copper, gold, or silver. the other end of the RF output coupling-element  506  is grounded to the outer conductive surface of the lamp body as illustrated in  FIG. 5A . Thus the design serves as an effective means of coupling the RF energy to the gas filled vessel created by the RF source that flows into the resonating structure. 
     An advantage of the present embodiment is that the post and helical structure RF output-coupling element serve as a more effective means of dissipating heat from the bulb within the resonating structure thus creating improved device heat transfer characteristics. That is, the post structure draws a substantial portion of the thermal energy generated from the bulb away through the material or coatings of the post structure, while maintaining the helical structure at a desirable temperature. Such desirable temperature leads to desirable conductive characteristics of the helical structure to maintain the performance (e.g., efficiency) of the plasma apparatus according to a specific embodiment. During the creation of a plasma, a great amount of heat is generated. The particles in the plasmas generated by such devices typically are at a temperature on the order of one thousand degree or of several thousand degrees Celsius. In order to prevent damage to the lamp and for the overall safety of the device, an effective means of dissipating the heat generated by the bulb is necessary. As the helical RF output coupling-element is coupled directly to the metal base which holds the bulb, the generated heat is conducted into the RF output coupling-element. The use of a helical shaped RF output coupling-element creates a structure with a larger surface area in which the heat can dissipate into the air. By creating a larger surface area in which the surrounding air comes into contact with, a greater amount of heat is dissipated from the bulb and out through the RF output-coupling element. The improved heat transfer characteristics of the lamp, leads to improved reliability and safety. 
     Another advantage of the present embodiment is that the use of a helical RF output coupling-element lowers the resonant frequency of the device, thereby allowing the device to operate at lower RF frequencies. Specifically, in creating a helical shaped RF output coupling-element structure, creates a large amount of magnetic flux within the structure, in turn leading to increased inductance levels of between 50% to about 1000% of that of the resonator structure according to one or more embodiments. In one or more preferred embodiments, the inductance increases from about 1.1 to 10 6  and greater. That is, the operating resonating frequency may be 50 kHz and greater, e.g., 10 MHz. The resonance frequency of the device is inversely related to the inductance, therefore at higher inductance levels, the resonance frequency is decreased. In decreasing the resonance frequency in the range of 8 MHz to about 1000 MHz, the device is capable of operating at lower RF frequencies, in turn becoming more efficient. Of course, there can be other variations, modifications, and alternatives. 
       FIG. 4B  is a simplified perspective view of an alternate embodiment of the present invention consisting of an RF output coupling-element that is helical in structure  907  and encompasses a dielectric material  908  with a metal insert  909  that allows for the tuning of the resonance frequency of the resonator. As with the previous embodiment, the RF output coupling-element of the present embodiment is connected to the metal post structure  905  that is used to support the bulb  130 . The other end of the output coupling-element  906  is grounded to the outer surface of the conductive lamp body as illustrated in  FIG. 9 . 
     The present embodiment incorporates a dielectric material within the helical RF output coupling-element. Such dielectric material can be but is not limited to Alumina or any other suitable dielectric or ceramic material. The dielectric material does not conduct the current that is generated from the RF source and flows through the RF output-coupling element, however, the dielectric material does absorb the heat from the helical coils of the RF output coupling-element and the heat from the bulb through the top of the coupling element  905 . Since dielectric materials are capable of absorbing large amounts of heat while providing electrical isolation, the use of a dielectric within the RF output coupling-element further improves the heat transfer characteristics of the lamp. Using a helical output coupling-element increases the inductance of the resonator reducing the resonance frequency of the resonator, thereby allowing for operation the lamp at lower RF frequencies. 
     The present embodiment also incorporates a metal insert  909  between the dielectric material and the helical RF output coupling-element. The metal insert makes contact at one end with the helical RF output coupling element and at the other end makes contact with the base  906  of the output coupling-element. The length of the metal insert is less than the length of the entire helical RF output coupling-element. However, the length of the metal insert can be adjusted such that it can make contact at different positions along the length of the helical RF output coupling element. One method of adjusting the length of the metal insert is by using screw threads along the length of the metal insert and turning the metal insert into the base of the output coupling element to adjust its length. Of course other methods of adjusting the length of the metal insert are possible. As the length of the metal insert is adjusted such that it makes contact with the helical output coupling-element at different positions, the inductance of the output coupling-element changes resulting in changes in the resonant frequency of the resonator. The metal insert can be used to tune the resonant frequency of the resonator to optimize the performance of the lamp and improve manufacturing yield. 
       FIG. 5A  illustrates the cross-section for a coil electrodeless plasma lamp according to an embodiment of the present invention. Energy from an RF source is directed to the input port  502  of the resonator enclosure  501 . RF Energy is coupled into the resonator enclosure  501  through a standard RF connector  503 . A straight resonator coupling element  504  that has one end connected to the RF connector and the other end grounded, directs the RF energy inside the resonator and couples the energy to the output support structure comprised of elements  505 ,  506 , and  507 . The output support structure is comprised of three elements. The conductive grounded support base  506  provides a physical and electrical connection to the resonator on one end and a connection to the coil element  507  on the other end. The coil element is an electrically conductive material configured into a helical structure to extend through the resonator enclosure to support and connect to the output support structure  505 . The output support structure  505  can be made of any electrically conductive or non-conductive material (ceramic) but must have its surface covered with an electrically conductive layer. The output support structure directs the RF energy that is coupled to it from the resonator coupling element  504  into the gas-filled vessel  130  where light is produced. 
       FIG. 5B  illustrates the cross-section for a coil electrodeless plasma lamp according to an embodiment of the present invention. Energy from an RF source is directed to the input port  502  of the resonator enclosure  501 . RF Energy is coupled into the resonator enclosure  501  through a standard RF connector  503 . A straight resonator coupling element  504  that has one end connected to the RF connector and the other end grounded, directs the RF energy inside the resonator and couples the energy to the output support structure comprised of elements  505 ,  506 ,  507 , and  508 . The output support structure is comprised of four elements. The conductive grounded support base  506  provides a physical and electrical connection to the resonator on one end and a connection to the coil element  507  on the other end. The coil element is an electrically conductive material configured into a helical structure to extend through the resonator enclosure. A non-conductive (ceramic) support structure  508  is used to physically support the coil element  507  and output support structure  505  and facilitate heat transfer from the gas-filled vessel  130  to the rest of the resonator. It is directly attached to the output support structure  505 . The output support structure can be made of any electrically conductive or non-conductive material (ceramic) but must have its surface covered with an electrically conductive layer. The output support structure directs the RF energy that is coupled to it from the resonator coupling element  504  into the gas-filled vessel  130  where light is produced. 
       FIG. 5C  illustrates the cross-section for a coil electrodeless plasma lamp according to an embodiment of the present invention. Energy from an RF source is directed to the input port  502  of the resonator enclosure  501 . RF Energy is coupled into the resonator enclosure  501  through a standard RF connector  503 . A straight resonator coupling element  504  that has one end connected to the RF connector and the other end grounded, directs the RF energy inside the resonator and couples the energy to the output support structure comprised of elements  505 ,  506 ,  507 , and  509 . The output support structure is comprised of four elements. The conductive grounded support base  506  provides a physical and electrical connection to the resonator on one end and a connection to the coil element  507  on the other end. The coil element is an electrically conductive material configured into a helical structure to extend through the resonator enclosure. A non-conductive (ceramic) support structure  509  is used to physically support the output support structure  505  and facilitate heat transfer from the gas-filled vessel  130  to the rest of the resonator. It is directly attached to the output support structure  505 . The output support structure can be made of any electrically conductive or non-conductive material (ceramic) but must have its surface covered with an electrically conductive layer. The output support structure directs the RF energy that is coupled to it from the resonator coupling element  504  into the gas-filled vessel  130  where light is produced. 
       FIG. 5D  illustrates the cross-section for a coil electrodeless plasma lamp according to an embodiment of the present invention. Energy from an RF source is directed to the input port  502  of the resonator enclosure  501 . RF Energy is coupled into the resonator enclosure  501  through a standard RF connector  503 . A straight resonator coupling element  504  that has one end connected to the RF connector and the other end grounded, directs the RF energy inside the resonator and couples the energy to the output support structure comprised of elements  505 ,  506 ,  508 , and  510 . The output support structure is comprised of four elements. The conductive grounded support base  506  provides a physical and electrical connection to the resonator on one end and a connection to the coil element  510  on the other end. The coil element is an electrically conductive material configured in the shape of conductive stripes onto the non-conductive (ceramic) support structure  508  and provides an electrical connection to the output support structure  505 . The non-conductive support structure  508  is used to physically support the output support structure  505  and facilitate heat transfer from the gas-filled vessel  130  to the rest of the resonator. It is directly attached to the output support structure  505 . The output support structure can be made of any conductive or non-conductive material (ceramic) but must have its surface covered with an electrically conductive layer. The output support structure directs the RF energy that is coupled to it from the resonator coupling element  504  into the gas-filled vessel  130  where light is produced. 
       FIG. 6A  illustrates the cross-section for a coil electrodeless plasma lamp according to an embodiment of the present invention. Energy from an RF source is directed to the input port  602  of the resonator enclosure  601 . RF Energy is coupled into the resonator enclosure  601  through a standard RF connector  603 . A coil resonator coupling element  604  that has one end connected to the RF connector and the other end grounded surrounds the center support structure assembly and directs the RF energy inside the resonator to couple the energy to the output support structure comprised of elements  605 ,  606 , and  607 . The output support structure is comprised of three elements. The conductive grounded support base  606  provides a physical and electrical connection to the resonator on one end and a connection to the coil element  607  on the other end. The coil element is an electrically conductive material configured into a helical structure to extend through the resonator enclosure to support and connect to the output support structure  605 . The output support structure  605  can be made of any electrically conductive or non-conductive material (ceramic) but must have its surface covered with an electrically conductive layer. The output support structure directs the RF energy that is coupled to it from the resonator coupling element  604  into the gas-filled vessel  130  where light is produced. 
       FIG. 6B  illustrates the cross-section for a coil electrodeless plasma lamp according to an embodiment of the present invention. Energy from an RF source is directed to the input port  602  of the resonator enclosure  601 . RF Energy is coupled into the resonator enclosure  601  through a standard RF connector  603 . A coil resonator coupling element  604  that has one end connected to the RF connector and the other end grounded surrounds the center support structure assembly and directs the RF energy inside the resonator to couple the energy to the output support structure comprised of elements  605 ,  606 ,  607 , and  608 . The output support structure is comprised of four elements. The conductive grounded support base  606  provides a physical and electrical connection to the resonator on one end and a connection to the coil element  607  on the other end. The coil element is an electrically conductive material configured into a helical structure to extend through the resonator enclosure. A non-conductive (ceramic) support structure  608  is used to physically support the coil element  607  and output support structure  605  and facilitate heat transfer from the gas-filled vessel  130  to the rest of the resonator. It is directly attached to the output support structure  605 . The output support structure can be made of any electrically conductive or non-conductive material (ceramic) but must have its surface covered with an electrically conductive layer. The output support structure directs the RF energy that is coupled to it from the resonator coupling element  604  into the gas-filled vessel  130  where light is produced. 
       FIG. 6C  illustrates the cross-section for a coil electrodeless plasma lamp according to an embodiment of the present invention. RF Energy is coupled into the resonator enclosure  601  through a standard RF connector  603 . A coil resonator coupling element  604  that has one end connected to the RF connector and the other end grounded surrounds the center support structure assembly and directs the RF energy inside the resonator to couple energy to the output support structure comprised of elements  605 ,  606 ,  607 , and  609 . The output support structure is comprised of four elements. The conductive grounded support base  606  provides a physical and electrical connection to the resonator on one end and a connection to the coil element  607  on the other end. The coil element is an electrically conductive material configured into a helical structure to extend through the resonator enclosure. A non-conductive (ceramic) support structure  609  is used to physically support the output support structure  605  and facilitate heat transfer from the gas-filled vessel  130  to the rest of the resonator. It is directly attached to the output support structure  605 . The output support structure can be made of any electrically conductive or non-conductive material (ceramic) but must have its surface covered with an electrically conductive layer. The output support structure directs the RF energy that is coupled to it from the resonator coupling element  604  into the gas-filled vessel  130  where light is produced. 
       FIG. 6D  illustrates the cross-section for a coil electrodeless plasma lamp according to an embodiment of the present invention. RF Energy is coupled into the resonator enclosure  601  through a standard RF connector  603 . A coil resonator coupling element  604  that has one end connected to the RF connector and the other end grounded surrounds the center support structure assembly and directs the RF energy inside the resonator to couple energy to the output support structure comprised of elements  605 ,  606 ,  608 , and  610 . The output support structure is comprised of four elements. The conductive grounded support base  606  provides a physical and electrical connection to the resonator on one end and a connection to the coil element  610  on the other end. The coil element is an electrically conductive material configured in the shape of conductive stripes onto the non-conductive (ceramic) support structure  608  and provides an electrical connection to the output support structure  605 . The non-conductive support structure  608  is used to physically support the output support structure  605  and facilitate heat transfer from the gas-filled vessel  130  to the rest of the resonator. It is directly attached to the output support structure  605 . The output support structure can be made of any electrically conductive or non-conductive material (ceramic) but must have its surface covered with an electrically conductive layer. The output support structure directs the RF energy that is coupled to it from the resonator coupling element  604  into the gas-filled vessel  130  where light is produced. 
       FIG. 7A  illustrates the cross-section for an electrodeless plasma lamp with a coil resonator coupling element according to an embodiment of the present invention. Energy is coupled into the resonator enclosure  701  through a standard RF connector  703 . A coil resonator coupling element  704  that has one end connected to the RF connector and the other end grounded is situated from the connector to the opposite end of the resonator without encircling the output support structure  705 . The output support structure is connected to the gas-filled vessel  130  at one end and connected to ground (resonator enclosure) at the other end. The output support structure  705  is used to physically support and facilitate heat transfer from the gas-filled vessel  130  to the rest of the resonator. The output support structure can be made of any electrically conductive or non-conductive material (ceramic) but must have its surface covered with an electrically conductive layer. The output support structure directs the RF energy that is coupled to it from the resonator coupling element  704  into the gas-filled vessel  130  where light is produced. 
       FIG. 7B  is a simplified cross section of a coil electrodeless plasma lamp with a coil resonator coupling element according to an embodiment of the present invention. Energy is coupled into the resonator enclosure  701  through a standard RF connector  703 . A coil resonator coupling element  704  that has one end connected to the RF connector and the other end grounded is situated from the connector to the opposite end of the resonator without encircling the output support structure that is also in the form of a coil similar to  FIG. 5A . The output support structure is comprised of three elements,  705 ,  706 , and  707 . The conductive grounded support base  706  provides a physical and electrical connection to the resonator on one end and a connection to the coil element  707  on the other end. The coil element is an electrically conductive material configured into a helical structure to extend through the resonator enclosure to support and connect to the output support structure  705 . The output support structure  705  can be made of any electrically conductive or non-conductive material (ceramic) but must have its surface covered with an electrically conductive layer. The output support structure directs the RF energy that is coupled to it from the resonator coupling element  704  into the gas-filled vessel  130  where light is produced. 
       FIG. 8  illustrates the cross-section for a coil electrodeless plasma lamp according to another embodiment of the present invention. Energy from an RF source is directed to the input port  802  of the resonator enclosure  801 . In this case, the input is situated on the side of the resonator. RF Energy is coupled into the resonator enclosure  801  through a standard RF connector  803 . A coil resonator coupling element  804  that has one end connected to the RF connector and the other end grounded surrounds the output support structure assembly and directs the RF energy inside the resonator to couple the energy to the output support structure comprised of elements  805 ,  806 ,  808 , and  810 . The output support structure is comprised of four elements. The electrically conductive grounded support base  806  provides a physical and electrical connection to the resonator on one end and a connection to the coil element  810  on the other end. The coil element, made from an electrically conductive material, is configured into a helical structure to extend through the resonator enclosure. A non-conductive (ceramic) support structure  808  is used to physically support the coil element  810  and output support structure  805  and facilitate heat transfer from the gas-filled vessel  130  to the rest of the resonator. It is directly attached to the output support structure  805 . The output support structure can be made of any electrically conductive or non-conductive material (ceramic) but must have its surface covered with an electrically conductive layer. The output support structure directs the RF energy that is coupled to it from the resonator coupling element  804  into the gas-filled vessel  130  where light is produced. 
       FIG. 9  illustrates the cross-section for a coil electrodeless plasma lamp according to an embodiment of the present invention. Energy from an RF source is directed to the input port  902  of the resonator enclosure  901 . Energy is coupled into the resonator enclosure  901  through a standard RF connector  903 . A straight resonator coupling element  904  that has one end connected to the RF connector and the other end grounded, directs the RF energy inside the resonator and couples the energy to the output support structure comprised of elements  905 ,  906 ,  907 ,  908 , and  909 . The output support structure is comprised of five elements and is similar to the structure illustrated in  FIG. 4B . The conductive grounded support base  906  provides a physical and electrical connection to the resonator on one end and a connection to the coil element  907  on the other end. The coil element, made from an electrically conductive material, is configured into a helical structure to extend through the resonator enclosure to support and connect to the output support structure  905 . The output support structure  905  is connected to gas-filled vessel  130  at one end and to the coil element  907  and a support post  908  made from a non-conductive material (ceramic) at the other end. The output support structure  905  can be made of any electrically conductive or non-conductive material (ceramic) but must have its surface covered with an electrically conductive layer. An electrically conductive adjustable element  909  is used to tune the resonant frequency by traveling up and down the coil element. The adjustable element must be in electrical contact with the coil element  907 . The output support structure directs the RF energy that is coupled to it from the resonator coupling element  904  into the gas-filled vessel  130  where light is produced. 
       FIG. 10  illustrates the cross-section for a coil electrodeless plasma lamp according to an embodiment of the present invention. Energy from an RF source is directed to the input port  1002  of the resonator enclosure  1001 . Energy is coupled into the resonator enclosure  1001  through a standard RF connector  1003 . A coil resonator coupling element  1004  that has one end connected to the RF connector and the other end grounded surrounds the center support structure assembly and directs the RF energy inside the resonator to couple energy to the output support structure comprised of elements  1005 ,  1006 ,  1007 , and  1009 . The output support structure is comprised of four elements. The conductive grounded support base  1006  provides a physical and electrical connection to the resonator on one end and a connection to the coil element  1007  and a non-conductive (ceramic) support structure  1009  on the other end. The coil element is an electrically conductive material configured into a helical structure to extend through the resonator enclosure and is connected at the other end to the top portion of the output support structure  1005 . The non-conductive (ceramic) support structure  1009  is used to physically support the output support structure  1005 , which in this case has an extended post to the lower portion of the resonator, and to facilitate heat transfer from the gas-filled vessel  130  to the rest of the resonator while providing a DC block. The output support structure can be made of any electrically conductive or non-conductive material (ceramic) but must have its surface covered with an electrically conductive layer. The output support structure directs the RF energy that is coupled to it from the resonator coupling element  1004  into the gas-filled vessel  130  where light is produced. 
       FIG. 11  illustrates the cross-section for a coil electrodeless plasma lamp according to an embodiment of the present invention. This embodiment is similar to the one shown in  FIG. 5A  except that around the output support structure  505 , at the top section of the resonator enclosure  501 , is filled with a dielectric material  511  (for example quartz or alumina) to further lower the resonant frequency of the resonator. It is also possible to partially or completely fill the bottom portion of enclosure  501  with a dielectric material as well. 
     While the above is a full description of the specific embodiments, various modifications, alternative constructions and equivalents may be used. As used herein, the term “coil” may include regularly spaced windings or irregularly spaced windings, as well as spiral, rectangular, helical, annular, polygon, or any combination of these, and others that would be understood by one of ordinary skill in the art. Additionally, the terms “input coupling” and “output coupling” have been used in the above embodiments, but such terms can be described more generally as a resonator coupling element, an RF coupling element, or such terms as support structure(s) and combinations, as well as other well known ordinary meanings. Therefore, the above description and illustrations should not be taken as limiting the scope of the present invention which is defined by the appended claims.

Technology Classification (CPC): 7