Abstract: A portable multiband H.F. antenna that has minimum ground area requirements and that is capable of transmitting electromagnetic wave radiation with horizontal polarization, azimuth plane omnidirectional patterns and a null in the vertical beam pattern is realized by means of an easily erectable tower type radiator. The tower structure has adjacent conductive leg members that define an elongated antenna slot aperture the total length of which is resonant to the lowest operating frequency band. A microwave transmission line resides along one side of the slot and the slot aperture is fed by shorting the transmission line to the oposite side of the slot. Operation at higher frequency bands is achieved by shorting out sections of the slot aperture on both sides of the feed. An array of radiating slot apertures can be provided by shorting the full slot aperture into sections and feeding each slot section separately.

Abstract: Extremely sensitive velocity and position measurements are achieved with a surface acoustic wave (SAW) resonator device. A surface acoustic standing wave field is established on a movable SAW propagation surface by means of induced SAW pulses traveling on the propagation surface and their reflection from a SAW reflecting mechanism. Movement of the propagation surface causes periodic variations in the standing wave field amplitude. The frequency of the standing wave field amplitude variation is directly related to the SAW propagation surface velocity and its phase (i.e., total number of standing wave field amplitude variations from a reference point) indicates the SAW propagation surface position or how far it has moved from the reference point.One implementation comprises a rotatable aluminum cylinder on the surface of which SAWs are launched and detected by proximate but non-contacting transmitting and receiving electromagnetic transducers (EMTs).

Abstract: The generation of intense burst of high energy electrons and/or intense currents of positive ions is accomplished by compressing a magnetic field in the presence of a gas plasma. The gas plasma is contained in a metallic cylinder and the magnetic field is established by means of a capacitor bank driven current that flows in the axial direction on the metallic cylinder and returns through the gas plasma contained in the cylinder. Detonation of explosive material surrounding the metallic cylinder drives the cylinder walls inward effecting compression of the magnetic field and a concomitant increase in plasma current.

Abstract: Radar target back scattering is controlled by an impedance loading technique. The target is loaded with a variable impedance that is adjusted in response to the frequency of any incident radar signal to achieve optimum reflectivity for that particular frequency. Either radar target cross section reduction or enhancement is achieved over a broad band of frequencies by appropriate control of a voltage variable capacitance diode.

Abstract: Shielding from and the termination of high power infrared laser beams is accomplished by interception of the beam by one of two spaced, juxtaposed, ceramic sheet members. The beam intercepting member has a thickness to beam power density relationship that allows opaque to translucent conversion of the portion thereof illuminated by the beam. The translucent portion subsequently diffuses the beam. The diffused beam is then absorbed by the second ceramic sheet member.

Abstract: A singly rotated propagation surface defining cut of single crystal berlinite (AIPO.sub.4) is utilized to provide a temperature compensated surface acoustic wave (SAW) substrate having a high piezoelectric coupling factor. The preferred embodiment of the invention comprises a berlinite substrate member having a propagation surface that substantially coincides with a plane defined by Euler angles Lambda = 0.0.degree., mu = 80.4.degree., and Theta = 0.0.degree..

Abstract: Doubly rotated propagation surface defining cuts of single crystal berlinite (AIPO.sub.4) are utilized to provide temperature compensated surface acoustic wave (SAW) substrates having high piezoelectric coupling factors and low diffraction losses. A preferred embodiment of the invention comprises a berlinite substrate member having a propagation surface that substantially coincides with a plane defined by Euler angles Lambda = 76.8.degree., mu = 90.0.degree., and Theta = 11.5.degree.. An alternative embodiment utilizes a propagation surface that substantially coincides with a plane defined by Euler angles Lambda = 79.7.degree., mu = 90.0.degree., and Theta = 15.5.degree..

Abstract: MNOS memory circuit fabrication problems that result in leakage, memory device depletion mode switching and leakage paths at the edges of silicon islands are eliminated by a production process in which deposited and thermal oxides are used as a diffusion mask on the island edges, selective control of the threshold level of the memory device is achieved by ion implantation, and a thick oxide is grown on the silicon island edges to control charge injection.

Abstract: A low inductance, rapid response, heater for silicon photodetector and microcircuit applications is realized by depositing on a substrate surface a heater whose contact terminals and resistance element are configured to eliminate electrical noise due to the induced currents that commonly result from on-off switching action. The heater geometry utilizes a concentric ring configuration and consists of an inner disc-shaped contact terminal, a ring-shaped resistive heater element surrounding the disc-shaped contact terminal and an outer peripheral contact terminal surrounding the heater element. The heater is operated by means of an electrical current flowing in a radial direction through the circuit comprising the outer peripheral contact terminal, the annular resistive heater element and the inner contact terminal.

Abstract: A handheld, compact, self-contained transducer unit for electromagnetic generation and detection of ultrasound on or in metals and other media is realized by mounting short, flat cable sections directly on a small, powerful permanent magnet. The cable sections are interconnected in an electromagnetic transducer circuit configuration and the plane of the flat cable transducer circuit structure is perpendicular to the magnet magnetization axis. Fabrication of the device can be accomplished by selectively connecting the conductor ends of a flat strip electrical conductor segment and affixing the conductor segment to an appropriate surface of a samarium-cobalt permanent magnet.

Abstract: Effective shutter speed, focal plane exposure and film transport frame rate measurements are taken and displayed in user oriented format by a computing method and system for testing still and cinematic cameras. An analog signal pulse is generated that is responsive to the illuminance admitted to the camera focal plane during each camera shutter operation. Comparison of the analog signal pulse with various voltage threshold levels provides pulse period, overrange and underrange information. Cinematic frame rate is determined by dividing units by the time period, in seconds, between the beginnings of successive analog signal pulses; effective shutter speed is determined by dividing the peak amplitude value by the integrated value of the analog signal pulse; and focal plane exposure speed is determined by dividing the camera calibration constants by the integrated value of the analog signal pulse.

Abstract: A processing technique utilizing two separate silicon nitride depositions (one to form the memory regions and the second to form the nonmemory regions) is employed to provide a radiation hard drain source protected memory transistor. The amount of silicon dioxide used in the nonmemory regions is also minimized. A typical device comprises a mesa etched from a silicon-on-sapphire (SOS) wafer into which P+ source and drain regions are implanted. A 100 A layer of silicon dioxide and a second 1000 A layer of nonmemory silicon nitride covers the mesa and the two layers are etched to define a substrate gate window. The gate window is covered by a 25 A layer of tunneling oxide A final 500 A layer of memory silicon nitride covers the mesa structure. Contact windows are etched to accommodate source, drain and gate interconnect electrodes.

Abstract: Equalization and the individual control of the sensitivity of each element in a multi-element sensor array is achieved by means of a light transmitting element positioned to intercept light falling on the light receiving surface of each sensor element. Structurally the light transmitting device can be a single sheet of transparent ferroelectric ceramic having a long term polarization retention capability (or memory). A discrete portion of the sheet adjacent each sensor element is polarized in a manner that controls the level of light transmitted through the sheet at that locus and so controls the output level of the sensor adjacent to it. Equalization of sensor elements is accomplished by setting the polarization of each light transmitting element as a function of the difference between its associated sensor output voltage level and a standard voltage level in response to a constant intensity light source.

Abstract: Apparatus by which high explosive charges are propelled into and detonated at the center of an MHD-X generator. The high explosive charge units are engaged and propelled by a reciprocating ram device. Detonating in each instance is achieved by striking with a firing pin a detonator charge that is in register with a booster charge, the booster charge being in detonating communication with the high explosive charge. Various safety requirements are satisfied by a spring loaded slider operating in a channel transverse and adjacent to the booster charge. The slide retains the detonator charge out of register with the booster charge until a safety pin that holds the slider in place is pulled by a lanyard attached between the reciprocating ram and the safety pin. Removal of the safety pin permits the detonator charge to slide into alignment with the booster charge. Firing pin actuation is initiated by the slider at the instant the detonator charge and the booster charge come into register.

Abstract: A tool that permits assembly and disassembly of a variety of cannon plugs without the risk of plug damage commonly caused by pliers and other conventional assembly equipment. It comprises a multiplicity of differently sized Cannon plug holding members mounted on a wrench type fixture. A key and keyway arrangement prevents the plugs from turning while backshell and saddle clamps are attached or removed.

Abstract: The acceptance of all events and the processing of such events without lock-out in a multiple input data processing system is achieved by a random action event switching technique. Processing of all events in order of arrival is accomplished by providing an input line for each system input on which the priority of the received event is registered with the resolution of the switch timing clock. Events arriving on other lines during the same time resolution element are processed with equal priority but with identity preserved. At the end of each time interval accumulated events are switched to one of a multiplicity of event holding lines, there being fewer event holding lines than input lines, and the input lines are cleared to receive subsequently arriving events. Event holding lines are filled in selected sequence and are switched to the data system main processor for read-out according to the priority of arrival of the events they hold and in response to main processor availability signals.

Abstract: A conditioning circuit for a resistance bridge transducer that includes output signal amplification, a voltage regulated DC power source for transducer excitation and a calibration select circuit for selectively inserting a shunt calibration resistor into parallel with one bridge arm. The calibration select circuit comprises a field effect transistor switch that is connected in series with the calibration resistor between two adjacent transducer terminals. The field effect transistor switch is operated by the output of an operational amplifier in response to positive and negative DC control signals. The conditioning circuit is adaptable to miniaturization through the use of integrated and hybrid circuits.

Abstract: A film slewing device is incorporated into a contact printer of the type in which a free running inner copy film and a driven outer master film are transported in layered contact on the surface of a free wheeling drum through a light exposure region by use of a master film drive roller and a film coupling pressure roller. The slewing device can selectively provide independent drive of the master film while holding the copy film stationary. This is accomplished by use of a thin arcuate film separating member that is conformed to the outer surface of the drum and that slides on the outer surface of the copy film. The film separating member can be slideably inserted between copy and master films in the region of light exposure. It has idling rollers on its outer surfaces to permit free passage of the outer master film. The pressure roller is disengaged when the separating member is positioned between films to prevent movement of the copy film.

Abstract: Improved fidelity and reduced computational requirements are achieved in a linear predictive coding (LPC) system that utilizes multichannel signal processing and reduced sampling rates. The input analog signal is divided by filters into multiple, contiguous, substantially equal bandwidth signal components and each component is digitized and processed by a separate standard LPC transmit-receive system. Each transmit-receive system operates at a sampling rate that is equal to the normal sampling rate for the signal being processed divided by the number of channels or signal components used. The received signal components are filtered, converted to analog, and summed.

Abstract: Plasma vortex structures generated by coaxial theta pinch guns are compressed and amplified by secondary adiabatic compression. A pair of vortex rings originating at opposite ends of a vacuum chamber are caused to meet at the chamber center by the confining and guiding effects of a primary magnetic mirror. A secondary magnetic mirror starts to compress the plasma as soon as the collision has occurred. The secondary compression amplifies the electrical currents and mass motions already in the vortex rings when they leave the conical theta pinch guns. The amplification process heats the plasma by a process of turbulent heating to very high temperatures.