Abstract: There is described an EHID lamp that comprises a field applicator, a means for coupling RF power to the field applicator, and a discharge vessel; the discharge vessel being disposed within the field applicator and containing a discharge medium; the field applicator being comprised of a solid, transparent or translucent dielectric material and having an optical control surface and a conductive coating that substantially covers its external surfaces. By combining functions served by otherwise individual components, the EHID lamp of this invention has the potential for reducing parts count, improving RF coupling to the plasma, reducing shadowing, and improving reliability.

Abstract: There is described an EHID lamp that comprises a field applicator, a means for coupling RF power to the field applicator, and a discharge vessel; the discharge vessel being disposed within the field applicator and containing a discharge medium; the field applicator being comprised of a solid, transparent or translucent dielectric material and having an optical control surface and a conductive coating that substantially covers its external surfaces. By combining functions served by otherwise individual components, the EHID lamp of this invention has the potential for reducing parts count, improving RF coupling to the plasma, reducing shadowing, and improving reliability.

Abstract: An arc tube for a high intensity discharge lamp comprising a translucent body defining a discharge space and including spaced-apart electrodes; an arc generating and sustaining medium within the discharge space; and a starting aid contained within the discharge space, the starting aid comprising an electrically conductive stripe formed from a mixture of an electrically conductive material and the high temperature material.

Abstract: A discharge lamp system and method of operating a discharge lamp system in which vertical segregation of vapor phase species is reduced. Lamp power is modulated with an arc-straightening frequency and with a frequency that excites a combination radial plus longitudinal acoustic mode of the lamp. The combination radial plus longitudinal acoustic mode may be a combination first radial mode and nth longitudinal acoustic mode and may be excited with a single power frequency or a swept power frequency range. The two frequencies may be provided at the same time, or separately where the modulation at the arc-straightening frequency is 2 to 16 times longer than a subsequent modulation at the combination radial plus longitudinal acoustic mode.

Abstract: A light source, particularly suited for surgical and other medical illumination applications, includes an electrodeless lamp assembly, a reflector having the electrodeless lamp assembly mounted therein and high frequency power source for supplying high frequency power to the electrodeless lamp assembly. The electrodeless lamp assembly includes an electrodeless high intensity discharge lamp capsule including a light transmissive discharge envelope enclosing a discharge volume containing a mixture of starting gas and chemical dopant material excitable by high frequency power to a state of luminous emission. The luminous emission has a color rendering index greater than 85 and preferably has a color rendering index greater than 90. The luminous emission preferably has low energy in the spectral range of 800 to 1000 nanometers relative to energy in the visible spectral range.

Abstract: An electrodeless high intensity discharge lamp including a sealed light-transmissive envelope, a volatilizable chemical fill and an inert gas or nitrogen within the envelope. The chemical fill includes as a primary active component phosphorus or a volatilizable compound of phosphorus. The inert gas or nitrogen is at a pressure of less than 760 torr at ambient temperature, and assists in starting the lamp. Sufficient mercury may be added to the lamp fill to improve resistive heating, but addition of mercury is not required for emission. Sulfur, a sulfur compound, or a metal halide may be added to the fill as a secondary active component. The lamp envelope is coupled to a high frequency power source to produce a light emitting plasma discharge within the envelope.

Abstract: An electrodeless high intensity discharge lamp includes an electrodeless lamp capsule, first and second electric field applicators positioned so that the lamp capsule is between the electric field applicators, and a planar transmission line. The planar transmission line couples high frequency power from an input to the first and second electric field applicators and has a gap with in which the lamp capsule is positioned. A field symmetrizing conductor, preferably a thin wire, is located in an open side of the gap and is electrically connected to the ground plane of the planar transmission line. The field symmetrizing conductor is positioned such that the electric field in the lamp capsule is substantially symmetrical with respect to the lamp axis and is substantially colinear with the lamp axis.

Abstract: The present invention provides a method for using electrodeless high-intensity discharge (HID) lamps for automotive headlamp and similar applications requiring high/low beam operation (first and second beam orientation) of signaling. The HID lamp is excited with a high-frequency radio frequency (rf) signal. Modulation of the radio frequency signal is used to cause the arc of the HID lamp to selectively operate at an acoustic resonance point. At such a point, the arc undergoes a perturbation and is physically displaced from its quiescent position. When the lamp is placed at a focal or light-gathering point of an optical system having forward gain, displacement of the arc away from the focal point causes discernible changes in the far-field output of the optical system.

Abstract: 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.degree. intervals around the lamp capsule. The high frequency power applied to adjacent applicators is shifted in phase by 90.degree..

Abstract: An assembly includes an electrodeless discharge lamp disposed between a pair of field applicators, and an integral impedance matching structure for matching the impedance of the lamp and field applicators to the impedance of a power source. The structure includes a Tee junction, a transmission line including a first branch connecting a first output of the Tee junction to one of the field applicators. A second branch of the transmission line connects a second output of the Tee junction to the other field applicator. The difference between electrical lengths of the first and second branches are substantially shorter than a half-wavelength. The assembly is less complex and more compact than prior art which utilizes odd mode excitation via a half-wavelength balun transformer.

Abstract: An electromagnetic discharge apparatus including a solid state supply or lamp ballast for energizing an electrodeless high intensity discharge (HID) lamp in a dual-ended fashion. A low power signal from a high frequency oscillator is split into two separate signals with definite phase relationship which are coupled to separate power amplifiers. In one embodiment, the signal from the high frequency oscillator is mixed with a signal from a modulation oscillator to AM, FM or pulse-width (PWM) modulate the power delivered to the lamp. This technique permits better control over the balance of power delivered to the ends of the lamp.

Abstract: An electrodeless HID lamp formed with a power balanced coupling structure is disclosed. Microwave transmission to the discharge capsule is divided into two channels having an electrical length differential of about a half wave length. A balancing strap line is coupled between the two transmission lines where they deliver power to the field applicators for the discharge capsule. The strap line balances the power delivery between the two ends of the discharge tube.

Abstract: An improved apparatus for delivering energy to two field applicators includes a power divider electrically coupled to a planar transmission line connecting the two field applicators. The power divider receives an input microwave signal and delivers a first power signal to an applicator along a first leg of the line, and delivers a second power signal to the other applicator along a second leg of the line. The power divider is coupled to the transmission line at a point which is remote from the applicators such that the power signals will encounter substantially identical discontinuities as the signals are coupled into their respective applicators.

Abstract: A high frequency applicator for energizing electrodeless lamps is described. The applicators are end cups electrically attached to the ends of phased feed points of a planar transmission line, and facing each other so as to form a gap between the end cups. The end cups each have a concave surface facing the gap which forces an electric field concentration in the vicinity of the end cups and in the gap between the opposing end cups. Such a field configuration is useful for energizing a lamp capsule placed within the gaps formed by the end cups. The end cups can be made of metal or metallized ceramic.

Abstract: The present invention describes an electrodeless HID lamp fixture which utilizes conventional microwave printed circuit material to provide both coupling and impedance matching functions. The fixture provides a steady state input impedance of a predetermined (e.g. 50 .OMEGA. or 75 .OMEGA.) value allowing direct connection to a RF power supply. Microwave power is applied at the input of the impedance matching network/balun which transforms the steady-state impedance of the lamp to the predetermined value. The network include a quarter wave transformer having a shunt capacitor coupled to balun-applicator which supplies microwave power to the lamp. In a preferred embodiment, the quarter wave transformer, shunt capacitor and balun are all manufactured on a microstrip.

Abstract: A high frequency applicator for energizing electrodeless lamps is described. The applicators are made of two loops of wire electrically attached to the ends of phased feed points of a planar transmission line. The loops are face each other and are positioned so as to form a gap in which a lamp capsule is placed. Each loop is made of three partial turns, the first and second turns being parallel to each other, each partial turn having a first and second end and the third partial turn is attached to the second end of each partial turn and positioned orthogonal the first and second turns. The plane formed by the third turn makes a dihedral angle between 9.degree. and 135.degree. with the planar transmission line.

Abstract: A re-entrant radio frequency cavity geometry for a low-pressure microwave electrodeless lamp such as a compact fluorescent lamp is described. The re-entrant cavity makes use of the properties of a re-entrant coaxial cavity resonator. The electrodeless lamp may be fabricated to have a constant input impedance in both the on and off states. In addition, the lamp starts at a lower drive power than present high efficacy, compact fluorescent lamps.

Abstract: A power amplifier circuit utilizes vertical power transistors, such as static induction transistors, field effect transistors, or bipolar junction transistors, in a configuration where an ungrounded terminal serves as a common node while a separate reference terminal is connected directly to ground. A transformer of appropriate bandwidth couples an rf input signal to the input terminals of the transistor such that the input terminals are floating relative to ground. The novel amplifier circuit establishes separate electrical paths between the common terminal and the input circuit and between the common terminal and the output circuit. Thus, negative feedback is not present in the common lead, thereby improving gain, power output, and efficiency. Moreover, the circuit, in either a BJT, FET, or SIT configuration, can be fabricated on thinned semiconductor chips to form a transistor package in which the chips are bonded directly to the package heatsink.

Abstract: Ignition of high intensity discharge (HID) lamps can be enhanced by the application of ultrahigh frequency (UHF) electric fields at modest power levels. The implementation of UHF power assisted starting offers considerable advantage over known prior art lower frequency power starting methods. Solid state circuits and coupled means can be utilized as described therein.

Abstract: A low resistivity N-type layer is formed at the surface of a high resistivity N-type epitaxial layer which has been grown on a low resistivity N-type substrate of silicon. Parallel grooves are etched through the low resistivity N-type layer into the high resistivity N-type layer forming interposed ridges of silicon. When fabricating junction gate devices, P-type zones are formed at the end walls of the grooves by ion implantation. A layer of silicon oxide is formed on the side walls of the grooves exposing the silicon at the end walls of the grooves and at the surfaces of the ridges. A layer of a silicide-forming metal, specifically cobalt, is deposited. A rapid thermal annealing treatment is performed which causes the cobalt to react with the silicon and form cobalt silicide at the cobalt-silicon interfaces. The cobalt does not react with the silicon oxide at the side walls of the grooves. The unreacted cobalt is removed by an etching solution which does not attack the cobalt silicide.