Abstract: A pulse signal generator apparatus for producing an ultrafast, high-voltage pulser using a circumferentially illuminated, laser-switched radial transmission line transformer. The apparatus includes a radial transmission line transformer having a circular plate structure which can be coupled to a voltage source that becomes conductive upon the application thereto of a predetermined type of light energy. A laser switching device which is integral with the radial transmission line transformer and surrounds the circular plate structure, operates to switch an input electrical pulse of a predetermined peak voltage, injected at a circumferential edge of the circular plate structure onto a peripheral surface of the circular plate structure, to produce an output electrical pulse having a substantially higher peak voltage than the predetermined peak voltage of the input electrical pulse, at a center of the circular plate structure of the transmission line transformer.

Abstract: A photon triggered RF radiator having separate sections to perform the eny storage and the energy radiation functions. The energy storage function is performed by at least one charging electrode positioned on the upper surface of a photoconductive dielectric substrate, whereas the energy radiation function is performed by a charging electrode positioned adjacent to the charging electrode on the upper surface of the substrate. The charging electrode and the radiating electrode are separated by a predetermined gap distance that is large enough to insure there is no surface flashover between the electrodes and small enough to insure the efficiency of energy discharge from the charging pad to the spiral antenna is maximized.

Abstract: A monolithic photoconductive pulsar utilizing a radial transmission line structure to store energy and a unique optical pulse illumination means to trigger the radial transmission line to radiate extremely, high voltage gain, narrow bipolar pulses. By achieving a higher voltage gain, the bipolar RF pulses are desirable in that they substantially improve the efficiency and lifetime of the device over the prior art.

Abstract: A photoconductive switch coupled to an energy storage device wherein the tch is comprised of photoconductive semiconductor material while the energy storage device comprises two spiral metalized arms that make up a spiral antenna. The photoconductive switch is electrically connected to the storage device to facilitate fast discharge of the stored energy through a load. A variation comprises a storage device comprising two separate pieces of substrate material each having a spiral metalized arm. The separate pieces being connected by highly dielectric material to form a spiral antenna ultra wideband radiator.

Abstract: A photoconductive ultra-wideband impulse generating device utilizing pulse harpening techniques to further increase its radiation frequency well above the gigahertz range while also substantially improving radiation efficiency. Such pulse sharpening provides for a radiator having a wider range of applications.

Abstract: An electronically controlled frequency agile impulse source utilizing pulse sharpening techniques to increase its versatility in radiating impulse energy at a variety of center frequencies and bandwidths in the megahertz to the gigahertz range. Such pulse sharpening provides for a radiator having a wider range of applications.

Abstract: The present invention comprises a semi-insulating layer of GaAs with p+ and layers of aluminum gallium arsenide AlGaAs grown on one side of the semi-insulating GaAs and with p and n+ layers of AlGaAs grown on the other side of the semi-insulating GaAs. Ohmic contacts are grown on both sides of the thyristor as well as low temperature GaAs to provide for surface passivity.

Abstract: A photoconductive switch coupled to an energy storage device wherein the tch is comprised of photoconductive semiconductor material while the energy storage device comprises two discrete dielectric mediums. Each medium having a conductive electrode on the top and bottom surfaces to essentially form parallel capacitors wherein the parallel capacitors are separated by a predetermined gap distance. A photoconductive switch electrically connected to each medium such that the switches are located on the opposite sides of their respective mediums. The predetermined gap distance (between the electrodes) and the photoconductive switches (on opposite sides of the storage devices) provide suppression of surface flashover between very high voltage, charged electrodes. Such flashover suppression allowing for very high power pulse generation.

Abstract: The combination of a photoconductive switch coupled to an energy storage ice wherein the switch is comprised of photoconductive semiconductor switch while the energy storage device comprises a tapered radio transmission line. A photoconductive semiconductor gallium arsenide switch is embedded in a circular disc of dielectric material having a thickness dimension which reduces linearly outward from the center, with upper and lower layers of continuous radial metallization configured in a circular pattern located thereon. The upper layer of metallization includes an apertured grid adjacent one surface of the switch, while the outer conductor of a coaxial output signal line is connected to the metallization layer on the opposite side with the inner conductor thereof passing through the dielectric layer to the undersurface of the semiconductor switch.

Abstract: Bulk gallium arsenide having a high hold-off voltage is optically activated by a laser resulting in high power output. A high voltage input is applied to a semi-insulating gallium arsenide material. The gallium arsenide material is activated by laser light, thereby resulting in large current conduction. An external oscillating signal is superimposed on the high current resulting in a high power output.

Abstract: A device for generating pulses of radio frequency energy in response to pulses of laser light in which a circular wafer of GaAs has metallized annular layers ohmically bonded to the wafer by epitaxial GaAs layers, and an epitaxial layer of AlGaAs in the center of one of the annular epitaxial layers through which laser light is to be directed, there being a plurality of apertures in the metallized layer in contact with the AlGaAs epitaxial layer. In addition, an AlGaAs epitaxial layer may be formed opposite the first AlGaAs layer and an optical fiber is brought into contact with it so that laser light can be introduced at both sides of the wafer.

Abstract: The present invention describes a method of explosively vaporizing a piece f semiconductor material in a plasma formed by a fast, high voltage current pulse. The semiconductor material may be formed from crystalline, polycrystalline, or amorphous forms of semiconductor material. After the semiconductor material is vaporized, it coalesces as the plasma begins to cool and is deposited in a collection system. The size and composition of the microparticles formed by this process can be controlled by conditioning the plasma in predetermined manners. In particular, impurities can be introduced either in the target material, in gas introduced in the plasma, or in the gas through which the coalescing microparticles travel prior to deposition.

Abstract: A photoconductive switch coupled to an energy storage device wherein the tch is comprised of photoconductive semiconductor material while the energy storage device comprises two quasi-radial transmission line including a different material, i.e. a dielectric storage medium. The photoconductive semiconductor gallium arsenide switch is electrically connected to two quasi-radial transmission lines formed in part by layers of metallization configured in a quasi-radially shaped pattern upon the energy storage device. A variation comprises a photoconductive semiconductor gallium arsenide wafer sandwiched between two quasi-radial transmission lines so that the semiconductor gallium arsenide wafer serves as substrate, energy storage medium, and photoconductive switch.

Abstract: A high voltage sub-nanosecond pulser and radiator including a radial transsion line consisting of a dielectric member sandwiched between two patterned layers of metallization, one of which comprises a plurality of radiating elements. A photoconductive semiconductor gallium arsenide switch is embedded in the dielectric member which has a constant thickness. The other layer of metallization includes an apertured grid adjacent one surface of the switch for application of an energization pulse of laser light.

Abstract: The combination of a photoconductive switch coupled to an energy storage ice wherein the switch is comprised of photoconductive semiconductor material while the energy storage device comprises a radio transmission line including a different material, i.e. a dielectric storage medium. A photoconductive semiconductor gallium arsenide switch is embedded in a circular disc of dielectric material with upper and lower layers of continuous radial metallization configured in a circular pattern located thereon. The upper layer of metallization includes an apertured grid adjacent one surface of the switch, while the outer conductor of a coaxial output signal line is connected to the metallization layer on the opposite side with the inner conductor thereof passing through the dielectric layer to the undersurface of the semiconductor switch.

Abstract: A high power, solid state burst generator for producing RF pulses includes a plurality of transmission lines, such as coaxial cables, having one end connected across a load via a plurality of photoconductive switches, one for each line. The other end of the transmission lines are terminated in open ends and connected to a charging DC voltage. One set of lines is connected to a positive DC voltage +V while other set is connected to a negative DC voltage -V. A laser is coupled to one end of a plurality of fiber optic lines, each having a different length, for simultaneously launching switch pulses thereon. The other ends of the fiber optic lines are each coupled to a different one of the photoconductive switches for closing and opening the switches in a sequential fashion such that the lines are sequentially discharged through the load to generate a cyclic series of pulses.

Abstract: An optically activated avalanche GaAs switch having two opposing optical windows for receiving optical energy from an illumination source which may be, for example, a laser diode operating at a 1.06 micron wavelength. The switch is a semiconductor PIN structure including a substrate of intrinsic GaAs material within which is formed opposing highly doped deep recessed p+ and n+GaAs layers underlying a pair of ohmic contacts including outer annular layers of metallization which surround respective centrally located optical windows formed of AlGaAs. By illuminating the switch from opposite sides through the optical windows, electron-hole pairs are generated and a condition for an avalanche mode of operation is created in the center region of the device rendering it conductive.

Abstract: A high power pulse generating system for use in impulse radar systems and e like contains a plurality of pulser units. The pulser units are circular shaped PIN diodes which integrates a light activated switch and a storage capacitor into a single structure formed on a semiconducting wafer. The pulser units have the capability of outputting pulses having a width of less than one nanosecond, facilitating high power output. The outputs of the pulser units are combined when each of the pulser units is simultaneously discharged using multiple laser pulses. In another embodiment a voltage step-up transformer is formed by a PIN diode structure having a diameter of approximately 60 mm. This device has the capability of outputting voltage amplitudes equal to or greater than the voltage level used to charge the PIN diode.

Abstract: Waveform configuration and/or power accumulation are accomplished with a ial transmission line that includes a pair of electrodes. One electrode is segmented to have at least two independent sections disposed in radial sequence relative to an axis passing perpendicularly through the electrodes. Individual voltage levels are applied between each independent section and the other electrode, while optical switches are disposed between each radially adjacent pair of independent sections for controlling electrical conductivity therebetween. The magnitude of the individual voltages, as well as the phasing of the optical switches are determined in accordance with the desired waveform configuration and power level.

Abstract: A device for radiating pulses of radio frequency energy in response to pulses of laser light in which a metal layer is ohmically bonded to one side of a substrate of semiconductor material and an antenna is ohmically bonded to the other side of the substrate, there being at least one aperture in the metal layer for permitting laser light to reach the disk.