Gte Laboratories Incorporated

Joseph Martin Lech

Paul O Haugsjaa

Robert J Regan

William H McNeill

An apparatus for combining outputs of serially connected high frequency power sources includes a number of input ports, an output port, and a power combination structure. The power combination structure includes two outer conductive layers which extend from the input ports to the output port and one or more intermediate conductive layers which extend from the input ports to a power combination region. High frequency power from the input ports propagates to the power combination region and therein combines vectorially. The sum of the individual input power levels then propagates to the output port. The power combiner can be reversed and used as a power divider operating into serially connected loads. A preferred embodiment, including two copper clad dielectric members and an aluminum base, operates at about 915 MHz. The power combiner can be constructed in a coaxial configuration.

High frequency power combiner or power divider

A light source includes an electrodeless lamp having a generally cylindrically shaped envelope made of a light transmitting substance. A volatile fill material, enclosed within the envelope, emits light upon breakdown and excitation. A termination fixture has an outer conductor disposed around its inner conductor, both conductors having a first end which couples power to the lamp and a second end coupled to an alternating current power source. A first end of conductive means is coupled to the first end of the inner conductor, a second end of the conductive means being open-circuited. The conductive means has an electrical length whereby axial electric field maxima and minima occur thereon. The envelope is oriented centrally and axially within the conductive means so that an axial, non-toroidal arc occurs within the envelope, but does not attach to its interior walls, thereby enhancing the life of the lamp. The conductive means can be formed in a helical or spiral configuration. The spiral configuration can take various forms, such as constant or continuously varying. A small spherical conductor can be affixed to the second end of a helical conductive means to inhibit electrical breakdown from an otherwise sharp end. A power source operates at a frequency having a wavelength .lambda..sub.o. The discharge is contained in an envelope (having an internal length substantially n halves of an axial wavelength .lambda..sub.z) centrally located within the spiral conductive means. Axial electric field minima occur distances 2n.lambda..sub.z /4 from the open circuited end of the conductive means (i.e., at the ends of the envelope) and an axial non-toroidal arc occurs within the envelope but does not attach to its interior wall. If the outer conductor circumferentially surrounds the spiral conductive means and the envelope therewithin to form a cylinder having a radius b, and the spiral conductive means includes a coil having a radius a and a constant pitch p then ##EQU1## With certain designs, a plurality of arcs can occur within the envelope. An electrodeless lamp having a generally cylindrically shaped envelope with an internal length n.lambda./2 (wherein n is a positive integer) can be excited by providing an electric field consisting of a voltage standing wave with points of axial electric field minima separated from each other by a distance .lambda./2, and orienting the lamp with respect to the field so that the opposed ends of the lamp are aligned with different points of the axial electric field minima, so that an axial, non-toroidal arc occurs within the envelope but does not attach to its interior wall.

Methods of and apparatus for electrodeless discharge excitation

A starting assist control circuit for an electrodeless light source in which a UV source for assisting in starting an electrodeless lamp is coupled in series with the dc supply for a microwave power source for the lamp so that a reduced dc voltage is supplied to the microwave power source at lamp starting. At staring, a capacitive impedance element is coupled across the inner and outer conductors of the fixture to provide an additional starting assist by creating a condition of resonance in the fixture. A heat responsive bimetallic switch element associated with both the capacitor and the UV source automatically shorts out the UV source and decouples the capacitor after the lamp has started thereby permitting full dc power to the microwave power source during the operating condition of the lamp.

Automatic starting system for solid state powered electrodeless lamps

In a light source excited with power at a high frequency, an electrodeless lamp is located in a termination fixture comprising an inner and outer conductor, the lamp being located at the end of the inner conductor. An internal tuning element is located within the fixture for creating a resonant condition when the lamp is to be started to create a maximum electric field for initiating breakdown and excitation of the fill material within the lamp. The tuner may comprise a variable capacitance coupled in parallel across the conductors at the power input end of the fixture or a variable inductance connected across the conductors at the lamp end of the fixture.

Internal match starter for termination fixture lamps

A light source includes a source of high frequency power, an electrodelsss lamp and a termination fixture for coupling power to the lamp, the fixture having an outer conductor and an inner conductor whose length is adjustable for providing dynamic matching of the impedance of the lamp during the operating mode to the output impedance of the source. Variations in the power level from the source, such as is desirable in providing lamp brightness selectivity, vary both the real and imaginary components of the lamp impedance, and corresponding adjustments of the inner conductor length provide a tuning technique to compensate for these variations.

Adjustable length center conductor for termination fixtures for

A termination fixture for use in an electrodeless light source has an input impedance which is matched to the output impedance of a high frequency power source, even though the lamp which forms the termination for the fixture has a complex impedance when the lamp is in an excited state. The fixture has a pair of coaxial conductors of at least a quarter wavelength, the conductors being coupled to the source at one end and to the lamp at the other end. The conductors are shaped to create an impedance which matches the real component of the lamp impedance to the source impedance. A capacitor is formed across the inner and outer conductors at the source coupled end to compensate for the series capacitive reactance part of the lamp impedance at the lamp coupled end of the conductors.

Electrodeless light source utilizing a lamp termination fixture having

A termination fixture for exciting an electrodeless lamp with high frequency power matches a capacitive complex impedance of the lamp in an excited state to the output impedance of the high frequency source coupled to the fixture. The fixture has a pair of coaxial conductors which have a length of one quarter wavelength and which have a ratio of diameters effective to match the real impedance of the lamp to the impedance of the source. A helical coil couples the end of the inner conductor to the lamp. The purpose of the coil is to make the impedance of the lamp, as viewed, electrically, from the end of the inner conductor appear as having only the real component. The quarter wave fixture then matches the real impedance to the source impedance.

Helical coupler for use in an electrodeless light source

An improved termination fixture for an electrodeless light source matches the complex impedance of an electrodeless lamp during excitation to the output impedance of a high frequency power source coupled to the fixture. The inner conductor of the fixture has a first and a second section. The dimensions of the first section are such as to produce an input impedance whose reactive impedance part is much smaller than the reactive impedance part of the lamp impedance. The dimensions of the second section are such as to match the input impedance to the source output impedance.

Termination fixture for an electrodeless lamp

An electrodeless lamp is excited in a termination fixture by high frequency power, the lamp being located within the fixture at the end of an inner conductor whose end is shaped such as to inhibit the arc of the lamp from attaching to the lamp envelope. In one embodiment, the inner conductor end is shaped as a hollow helical coil which generates an axial and azimuthal electric field component to create a torodial arc within the lamp. In another embodiment the inner conductor end is cup-shaped to provide a field shielding effect which distributes the field strength more uniformly across the end of the inner conductor.

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Westford, MA, United States of America

Joseph Martin Lech