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: The disclosed system measures the phase relationship of first and second K signals received at a pair of receiving antennas. The antennas are connected to respective first and second converting circuits which convert the received signals into first and second CW signals. Each CW signal is subjected to chirp-Z processing so as to convert the first and second CW signals into first and second chirp-Z transforms, which are narrow pulses. Then, the phase relationship of the first and second narrow pulses is detected, so as to thereby detect the phase relationship of the first and second received BPSK signals. That phase information can be used, for example, to calculate the angle-of-arrival (AOA) of the received BPSK signals. Advantageously, each converting circuit includes a series connection of a frequency-doubling circuit, a bandpass filter, and a circuit for dividing frequency by two, in that order.

Abstract: A conventional hydride VPE reactor is modified by the addition of a gas switching manifold and the use of three way pneumatic valves in the manifold to alternately direct the flow of reactant gas mixtures into either the reactor or a vent line. With these additions, various predetermined gas mixtures of arsine, phosphine, and hydrogen selected by electronic mass flow controllers (GM1 and GM2) and predetermined gas mixtures of H.sub.2 and HCl (GM3) may be alternately infused into the reactor chamber or vented as desired. When GM3 is injected into the reactor chamber, the content of GaAs of the growing layer increases while the content of In decreases. Given this, when GM3 and GM2 are vented rather than injected into the furnace and GM1 is directed into the furnace, a layer of InGaAsP with a predetermined composition (A) will be deposited. Alternatively, when GM3 and GM2 are co-injected into the reactor and GM1 is be directed to the vent, a layer of InGaAsP of a predetermined composition (B) will be deposited.

Abstract: BPSK signals are detected by receiving an input signal containing the BPSK ignals to be detected, by means of a compressive receiver; applying the receiver output to a 90.degree. phase shifter which outputs a phase-shifted signal; applying the phase-shifted signal to a delay line which applies a further phase shift of -180.degree. to the phase shifted signal; and detecting the relative phase of the non-phase-shifted signal from the compressive receiver and the phase-shifted signal from the delay line by applying those signals to respective input ports of a phase detector, the output of the phase detector being indicative of detection of a BPSK signal. Advantageously, zero-crossings of the output signal of the phase detector are detected, and the output of the zero-crossing detector is low-pass-filtered.

Abstract: A microstrip electronic scan antenna array is provided comprising a hollow elongated octagonal-shaped housing formed by four quadrantially-disposed microstrip patch antenna arrays and four filler panels extending between the patch arrays. Three, independently-switchable microstrip Y-junction circulators are tandem interconnected in a double-ended wye configuration on a common dielectric substrate forming an octagonal end cover for the housing. Each of the three circulators acts as a single pole-double throw switch and the sequence of energization of the four microstrip patch antenna arrays is determined by controlling the sequence and direction of circulator coupling action of the three circulators.

Abstract: An FH interceptor for determining bandwidth, hop number, dwell time, hop e, channel spacing and hop frequencies. A compressive receiver, having a passband greater than the bandwidth, samples received signals at a scan rate greater than the hop rate. On each scan, the receiver separates the received signal into its frequency components. A histogram memory, connected to the receiver, stores a frequency distribution of the frequency components including the scan periods. A data processor uses the histogram memory to determine the FH parameters.

Abstract: Disclosed is a coplanar waveguide (CPW) which is connected directly into a balanced SAW transducer" via a tapered coplanar transmission line. Preferably, the CPW transition feeds directly into the "balanced transducer" such that the ground planes of the CPW taper directly into the outer (grounded) bus bars of the SAW transducer and the center conductor of the CPW feeds directly into the "hot" center electrode structure of the SAW transducer. This preferred structure is shown in FIG. 1. This balanced SAW transducer configuration provides better electrical shielding for lower electromagnetic feedthrough suppression and lower spurious signal levels. Moreover, the acoustic wave generated by this "balanced transducer" configuration provides a more uniform acoustic power distribution because the center conductor of the SAW transducer provides a waveguide effect wherein the acoustic energy tends to follow the slow velocity metal structure, thus forming an acoustic waveguide.

Abstract: A dielectric resonator oscillator having a resonant structure connected to an amplifier the output of which is fed back to the input of the resonant structure. The resonant structure includes a metal cavity in which a dielectric disk is centrally mounted by a low-loss dielectric post. A pair of microstrip transmission lines extend into the cavity to provide energy outputs and inputs. Dielectric and conductive tuning screws are mounted on the cavity walls. Electrical tuning is provided via a varactor diode whose bias is adjustable. The diode may be connected in series or parallel with the microstrip transmission line.

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: An improved passive IFF system operating as a supplement to a conventional adar system including a coded variable delay system to produce like time-coded variable phase delayed identifying signal components indicative of cooperating or friendly objects and which overlap signals of other reflecting echo signals from the objects. The IFF system is provided with a retro-directive type antenna. The overlapping cooperating or friendly signal components and the corresponding other echo reflecting object signals are simultaneously detected at the radar system which is provided with a compensating or complementary phase delay means time coded in the same manner as the identifying IFF signal components. The identifying IFF signal components are thus produced in uniform phase and are summed up to provide a signal at the radar system whose magnitude is relatively large as compared to the combined corresponding echo reflecting signals which are in random-phase relationship.

Abstract: A method and apparatus for preventing unauthorized sources from utilizing rcraft-borne I.F.F. for locating same. A bypass switch is inserted in the I.F.F. transponder antenna line which normally sends all incoming signals into a dummy load. Upon receipt of a proper interrogate command, the antenna is switched to the transponder.

Abstract: An optically controlled resonant tunnel diode oscillator assembly having a esonant tunnel diode (RTD) which, when voltage biased, oscillates at a free running frequency; an optical signal delivery system, such as a light intensity modulator connected to optical fibers; and other oscillator circuitry which one skilled in the art could readily adapt to the concepts of the present invention. In operation, the free running oscillation of the RTD can be frequency modulated or can be intensity locked to the intensity modulated optical signal delivered via the optical signal delivery system.

Abstract: A DC high voltage block comprising coupled lines etched upon a substrate and covered with a bubble-free, polyurethane insulating layer. The polyurethane insulating layer prevents DC voltage breakdown through air. This DC voltage block provides a planar, noncomplex circuit that can effectively provide voltage blockage up to 4500 volts. High voltage DC blocks of this nature have applications in vacuum tubes and IMPATT devices, as well as ferro-electric or electro-optic phase shifters. They are also employed to protect bias tees and electrical devices that employ bias tees.

Abstract: A permanent magnet having a shell of magnetic material and a hollow cavity. The shell is permanently magnetized to produce an axially tapered magnetic field in the cavity. In one embodiment, a segmented spherical magnetic shell has a concentric spherical cavity. An access port in the form of an axial hole passes through polar segments of the shell along its polar axis P. The shell ("magic sphere") is magnetized such that it is capable of producing a tapered magnetic field in the cavity. Both the magnitude and direction of the remanence B.sub.R of the shell material vary from segment to segment. Another embodiment shows a segmented cylindrical shell in the form of a ("magic ring"). The shell material has a magnetic remanence B.sub.R that varies in magnitude and direction from segment to segment. The shell produces a axially tapered field in the cavity.

Abstract: A permanent magnet having a shell of magnetic material and a hollow cavity. An access port passes through the shell and communicates with the cavity. The shell is permanently magnetized to produce a substantially uniform magnetic field in the cavity. The magnetization of the shell is the resultant of magnetization components M1 and M2. Components M2 are uniform in both magnitude and direction while components M1 are uniform in magnitude and nonuniform in direction. Also, components M1 and M2 are substantially equal in magnitude to each other and, in the regions adjacent the access port, are aligned in opposite directions. The shell comprises a plurality of magnetic segments and each segment is uniformly magnetized. In accordance with one embodiment, the shell and cavity are concentric spheres, and the access port includes an axial hole that passes through the spherical center.

Abstract: A camera system providing color night vision for use in reconnaissance, or he like. The system includes a first lens, a mirror subassembly for splitting the lens image into three images, a filter subassembly for respectively filtering the three images through a red filter and a green filter and a blue filter first and second and third intensifiers having respective first and second and third camera units which view the three images and send three image signals in series to a display monitor where the color image is viewed.

Abstract: A planar ferro-electric phase shifter which is compatible with commonly-u microwave transmission media to include microstrip, inverted microstrip, and slot line. The ferro-electric material, Ba.sub.x Sr.sub.1-x TiO.sub.3, which has a high dielectric-constant, is the phase shifting element. In the microstrip embodiment, the microstrip circuit consists of a ferro-electric element interposed between a conductor line and a ground plane. A DC voltage is applied between the conductor line and the ground plane, thereby controlling the dielectric constant of the ferro-electric material. The dielectric constant of the ferro-electric element in turn controls the speed of the microwave signal, which causes a phase shift. Microwave energy is prevented from entering the DC supply by either a high-impedance, low pass filter, or by an inductive coil. DC voltage is blocked from traveling through the microstrip circuit by a capacitive high-voltage DC bias blocking circuit in the ground plane.

Abstract: An optic modulator having a multiple quantum well structure which is fabrted of alternating layers of gallium arsenide and aluminum arsenide such that at zero electric field there is an indirect electron-hole transition between valence and conduction bands of the aluminum arsenide layers and gallium arsenide layers, respectively, and a direct electron-hole transition between the valence and conduction bands of the gallium arsenide wells. At zero field the multiple quantum well behaves much like bulk material due to the matching of the band gap energy levels of the gallium arsenide and aluminum arsenide. However, when a sufficient electric field is applied to the structure the energy levels decouple thereby modulating the wavelength of any light passing through the structure.

Abstract: An IR photodetector including an IR semiconductor detector with conductive layers on opposite, parallel surfaces. A semiconductor substrate supports the semiconductor IR detector. A circuit is connected across the semiconductor IR detector to provide a bias voltage and for measuring current flow through the semiconductor IR detector. The semiconductor IR detector has a lattice structure made up of a series of potential wells separated by relatively wide potential barriers such that each well has two confined energy levels. A thin spike barrier is placed in the center of alternate potential wells to tailor the absorption characteristics of the semiconductor IR detector. Multicolor operation is achieved by selecting the appropriate well widths for a first group of potential wells and by placing thin spike barriers in a second group of potential wells that are alternately placed between the wells of the first group.

Abstract: An antenna comprises a microstrip transmission line which includes a strip conductor and a ground plane conductor separated by a dielectric substrate; a portion of the substrate being adapted to enable energy within the substrate to radiate away from the microstrip transmission line. To permit frequency-scanning, the substrate has an antenna portion formed therein which is adapted to permit RF energy supplied to the microstrip transmission line to be directionally radiated away from the microstrip transmission line at the antenna portion, the direction of radiation being a function of the frequency of the supplied energy. The substrate may have greater capacitance at said antenna portion than at other portions of said substrate.