Abstract: A reconfigurable ring architecture for RF transport over fibers which eliminates the need for multiple pairs of fibers to serve multiple microcells and the need for backup communications lines as a result of system failure due to a fiber break. The ring architecture has a plurality of remote units which are interconnected to a host unit in a serial fashion. The host unit transmits signals to the plurality of remote units and receives signals from the plurality of remote units. Each of the remote units having photodetectors for receiving the transmitted signals and an antenna/transmitter for receiving other signals from another source; a splitter for splitting the transmitted signals into two parts, one part of the signals being output from the remote unit and the other part of the signals being transferred to adjacent remote units and then back to the host unit; and a transmitter for transferring the other signals from the remote unit to adjacent remote units and then back to the host unit.

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: Apparatus for supporting a group of optical fibers in proper alignment with associated laser devices and rear-facet photodetectors. The photodetectors and grooves for supporting the optical fibers are fabricated in a carrier member of device quality silicon. An array of a row of laser devices is moved laterally along a slot in the carrier member transverse to the grooves so as to align each laser device with a groove and with a photodetector. One or more carrier members may be mounted on a supporting structure adapted to receive them.

Abstract: A high-gain, high-frequency, high-power, push-pull amplifier employing a pair of static induction transistors (SIT's) in common-source configuration. A pair of capacitances each of approximately the same capacitive value as the drain-to-gate parasitic feedback capacitance of each SIT are cross-coupled between the drains and gates of the pair of SIT's to neutralize the drain-to-gate capacitances and provide stable operation.

Abstract: Energy source of a low power high frequency oscillator section driving a high power high gain amplifier section. The amplifier section includes one or more SIT's. The dc operating potential is applied to the drain electrode of one of the SIT's and is supplied to the other through a dc path from the source electrode of the one SIT to the drain electrode of the other. Operating potential from the dc biasing network between the source and gate electrode of an SIT in the amplifier section is conducted through a dc path to a transistor in the oscillator section to provide operating power for the oscillator section. The oscillator output is connected through a high frequency coupling dc blocking path to the amplifier input to provide a drive signal to be amplified and extracted at the amplifier output.

Abstract: A power source consisting of a low power high frequency oscillator section driving a high power high gain amplifier section. The amplifier section includes one or more SIT's. The dc operating potential is applied to the drain electrode of one of the SIT's and is supplied to the other through a dc path from the source electrode of the one SIT to the drain electrode of the other. Operating potential from the dc biasing network between the gate and source electrodes of an SIT in the amplifier section is conducted through a dc path to a transistor in the oscillator section to provide operating power for the oscillator section. The oscillator output is connected through a high frequency coupling dc blocking path to the amplifier input to provide a drive signal to be amplified and extracted at the amplifier output.

Abstract: High voltage, high frequency amplifier employing power transistors. The amplifier provides parallel ac signal amplification paths through each transistor and a single dc power path through the transistors in series. In one embodiment two FET's have their source electrodes connected to an input terminal and their drain electrodes connected to an output terminal so as to provide two parallel ac amplifying paths while blocking dc current flow. The drain electrode of the first FET is connected through an RF choke to source of dc operating potential, and its source electrode is connected through an RF choke to the drain electrode of the second FET. The gate electrode of the second FET is connected to ground. A single dc conductive path is thus provided between the source of operating potential and ground through the two FET's in series.

Abstract: High voltage, high frequency amplifier employing power transistors. The amplifier provides parallel ac signal amplification paths through each transistor and a single dc power path through the transistors in series. In one embodiment two FET's have their gate electrodes connected to an input terminal and their drain electrodes connected to an output terminal so as to provide two parallel ac amplifying paths while blocking dc current flow. The drain electrode of the first FET is connected through an RF choke to a source of dc operating potential, and its source electrode is connected through an RF choke to the drain electrode of the second FET. The source electrode of the second FET is connected to ground through a zener diode. A single dc conductive path is thus provided between the source of operating potential and ground through the two FET's in series.

Abstract: A high frequency amplifier utilizes series-connected transistors to achieve high voltage class C operation. High frequency input power is coupled to the gate of a first FET which is normally biased off. The source of a second FET is coupled to the drain of the first FET. The drain of the second FET, which forms the output of the amplifier, is coupled through a radio frequency choke to a supply voltage. The gate of the second FET is dc biased at about one half of the supply voltage. A capacitor coupled between the gate of the second FET and ground controls the level of high frequency power applied to the second FET. The amplifier can be operated at a dc voltage which is approximately equal to one half the sum of the individual breakdown voltages of the serially connected FET's.

Abstract: Energy-saving circuitry for a rapid-start fluorescent lighting system includes a reactance-modifying capacitor coupled in series with first and second fluorescent lamps and includes a filament switch which is operative to conduct filament heating current during starting of the first lamp. The filament switch is coupled between filaments at opposite ends of the first fluorescent lamp and triggers to a low impedance state in response to the lamp starting voltage. A capacitor bypass switch can be coupled in parallel with the reactance-modifying capacitor to reduce the impedance of the series circuit during lamp starting.

Abstract: A light source includes a high pressure discharge lamp and incandescent filaments which provide illumination during the warm-up and hot restart periods associated with the discharge lamp. A current regulator, which provides dc power to the discharge lamp, draws sufficient current through one filament to energize the filament only during discharge lamp warm-up. A second filament provides illumination during the period after the occurrence of a momentary power failure or power transient which is required by the discharge lamp to cool down to its maximum starting temperature. A bimetal switch permits current flow through the second filament when the discharge lamp is above the maximum starting temperature. An electronic switch permits current flow through the second filament when a current sensing resistor senses a lack of current through the discharge lamp.

Abstract: An electromagnetic discharge apparatus has a power coupling fixture which couples power to both ends of an electrodeless discharge vessel and produces a substantially uniform arc. Power can be coupled to the fixture from two high frequency power sources or can be coupled from a single high frequency power source by using a power divider. If power is coupled to the electrodeless discharge vessel from a single source, power transfer to the vessel is optimized when the electrical length of the circuit is an integral number of wavelengths. In an alternative embodiment, a second coupler is utilized in a conventional electrodeless light source to shape the electric fields and produce a more uniform arc.

Abstract: Radioactive materials are used to assist in starting a discharge in an electrodeless light source. The radioactive emissions predispose on the inner surface of the lamp envelope loosely bound charges which thereafter assist in initiating discharge. The radioactive material can be enclosed within the lamp envelope in gaseous or non-gaseous form. Preferred materials are krypton 85 and americium 241. In addition, the radioactive material can be dispersed in the lamp envelope material or can be a pellet imbedded in the envelope material. Finally, the radioactive material can be located in the termination fixture. Sources of alpha particles, beta particles, or gamma rays are suitable. Because charges accumulate with time on the inner surface of the lamp envelope, activity levels as low as 10.sup.-8 curie are effective as starting aids.

Abstract: An electrodeless light source having a termination fixture adapted for connection to a high frequency power source has an electrodeless lamp with a self-contained ultraviolet excitation source and a means for coupling power to the electrodeless lamp. The electrodeless lamp includes a main lamp cavity and an exciter lamp cavity within a single envelope. When power is applied to the fixture, the exciter lamp cavity emits ultraviolet radiation which assists starting of the arc discharge in the main lamp cavity.

Abstract: 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.

Abstract: A solid state microwave power source for providing microwave power to excite an electrodeless lamp is designed so as to provide an acceptable impedance matching characteristic during lamp warm-up when the lamp impedance is high and changing with temperature to provide sufficient power to the lamp during the running state when the lamp impedance is matched to the source. The microwave power source includes a dc power source providing power at variable levels, a microwave oscillator receiving the dc power to produce a microwave signal, and a microwave power amplifier. The oscillator has a transistor in a common base configuration, a microstrip capacitive feedback element to sustain oscillations, and an output impedance matching arrangement formed from microstrip. The microwave signal is amplified in the solid state power amplifier having a power transistor in a common base configuration.

Abstract: 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. An electronic circuit is provided which continuously decreases the DC current through the UV source and increases the DC voltage for the microwave power source in relation to the amount of light generated by the electrodeless lamp. More specifically, the emitter and collector of a transistor are coupled across the UV source to provide a shunt path and the potential of the base of the transistor is controlled by a photosensitive resistor which senses the amount of light from the lamp. As the lamp generates increased light, the transistor becomes more conductive, thereby continuously decreasing current to the UV source and increasing voltage to the microwave power source.

Abstract: 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.

Abstract: 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.