Abstract: A heterojunction structure made of two semiconductor layers is disclosed in hich light is applied to the structure and absorbed, and the emission of light from the structure is controlled by an electric field applied perpendicularly to the planes of the layers. It is further disclosed that the device can be employed as a selective light filter or modulator.

Abstract: An optical device is disclosed which includes first and second superlattice emiconductor regions. The first superlattice semiconductor region includes a plurality of alternating barrier and light absorbing layers which absorbs light of a first light frequency. The second superlattice region also includes a plurality of alternating barrier and light absorbing layers. However, the light absorbing layers of the second superlattice semiconductor region absorbs light of a different frequency.

Abstract: A control augmentation system for stabilization and control of flight vehes, wherein control of vehicle angular velocities in proportion to control input is effected, and where stabilization of the corresponding vehicle attitude is also effected. The system consists of both feedforward and feedback signal paths. The feedback paths provide augmentation of the vehicle's inherent stability. The feedforward paths augment the controllability factors available to the pilot. The control augmentation system is a solution to hingeless rotor control problems.

Abstract: A tunnel diode is disclosed wich includes a heterostructure consisting of a irst layer of GaSb.sub.1-y As.sub.y and a second layer of In.sub.1-x Ga.sub.x As. It is also disclosed that other alloys of Group III and Group V materials can be employed in a tunnel diode of the instant invention.

Abstract: What is disclosed is an antenna system for aircraft and one having particr utilization on a helicopter where there is a need, among other things, to eliminate insofar as possible rotor blade modulation of the signal radiated from on-board air-to-ground communication system in the 2 to 30 MHz band. The antenna comprises a current fed grounded loop-antenna having an electrical length which is relatively short with respect to the operating wavelength. The antenna conductor is mounted by means of insulators on the outside of the aircraft body, having one end connected to the transmitter while the other end is series connected to a lumped electrical inductance element whose opposite end is terminated in the metallic skin of the aircraft. The electrical inductance, moreover, is variable so as to resonate the antenna to the driving impedance of the transmitter.

Abstract: A pressure release assembly provides controlled depressurization of a sea gas-containing vessel, such as a xenon-filled arc lamp, when the temperature of the gas in the vessel reaches a value corresponding to a selected pressure. The assembly comprises a thin metallic rupture plate that hermetically seals an aperture in a wall of the vessel, and a back-up disc that is supported adjacent the other surface of the rupture plate. The back-up disc reinforces the rupture plate so as to prevent bursting of the rupture plate at pressures below the selected pressure. The back-up disc is made of a material that loses its tensile strength at the temperature corresponding to the selected pressure, whereby the weakening of the back-up disc at the selected pressure causes the rupture plate to burst. The back-up plate may be made of a eutectic alloy that melts at the temperature corresponding to the selected pressure.

Abstract: A cathode ray tube has an envelope comprised of a first glass and a faceplate comprised of a second glass, both glasses having different thermal coefficients of expansion. The envelope and faceplate are joined by a cylindrical, stress-absorbing glass member flame-sealed at one end to the envelope and frit-sealed at the other end to the faceplate. Importantly, the thermal coefficient of expansion of the stress-absorbing member is less than the coefficients of either the envelope or the faceplate.

Abstract: There is disclosed a universal electrical conductor pattern for both multilayer and single layer test substrates for tape bonded hybrids which is adapted to accept semiconductor chips of various sizes and numbers of leads. The pattern consists of four sets of equally spaced parallel rectangularly shaped outer lead bonding pads which are orthogonally arranged in a repetitive sequence around a chip bonding pad. Each set of outer lead bonding pads consists of a first subset of six like pads arranged adjacently in registration along one edge of the chip bonding pad, and second and third subsets of two outer lead bonding pads each arranged on either side of said first subset in parallel relationship therewith but set back from the corners of the chip bonding pad. The rectangularly shaped outer lead bonding pads extend away from the respective edges of the chip bonding pad a predetermined distance so as to accommodate either twenty four, thirty two or forty pin lead frames having a standard twenty mil lead spacing.

Abstract: A digital data communications system including control techniques and cirtry for providing ternary detection; that is, mark, space, mark or space indeterminate states. The indeterminate state is useful in preventing synchronism loss during momentary propagation disturbances and to provide tighter system control.

Abstract: A pulse generation system using an inductive energy storage technique is described. A high magnitude current flowing in a storage inductor is suddenly halted by means of a repetitive series interrupter device and an accompanying magnetic field coupled control circuit. The resulting high voltage generated causes breakdown across a spark gap and transmission of a high energy pulse to a load.

Abstract: 6. A communication security system including a transmitting system having a lurality of sources of carrier frequencies, a source of prescheduled noise, a suppressed carrier modulator and transmitter responsive to said carrier frequencies and to said prescheduled noise for transmitting only the resultant sidebands, and means for connecting said respective carrier sources to said modulator in accordance with a schedule to be communicated, and a receiving system having a synchronized source of identical prescheduled noise, a receiver multiplier responsive to said sidebands and said prescheduled noise to restore said carrier frequencies, and a plurality of filters each corresponding to one carrier frequency, whereby the outputs of said filters reproduce at said receiving system the schedule communicated from said transmitting system.

Abstract: A method for forming a drive wire hole in a ferrite toroid phase shifter pted to operate in the millimeter frequency range. The ferrite toroid is fabricated by the arc plasma spray process. A slab of boron nitride is initially bonded to the dielectric insert of the ferrite toroid and the ferrite powder is arc plasma sprayed on the composite boron nitride-dielectric structure. The formed ferrite toroid is then annealed, and during the annealing process, the boron nitride slab is completely sublimated to form the required drive wire hole.

Abstract: An enhancement type, self-aligned silicon gate complementary metal oxide semiconductor (CMOS)/silicon on sapphire (SOS) structure is made by generating all gate oxides and oxide isolated regions with dry oxygen at pressures above 1 atmosphere and at temperatures of 800.degree. C. to 825.degree. C. using ion implantation for all doping operations and plasma definition of all masking dielectrics.

Abstract: A moving target simulating system for marksmanship practice including a film projector having a modulating grid thereon for transmitting a modulated infrared light through a film aperture onto a viewing screen is disclosed. The aperture is optically superimposed on the target, and the modulated infrared light reflected from the screen is detected by detectors on the weapons when the weapons are accurately aimed and fired at the target.

Abstract: Clandestine signals are transmitted by using a surface wave acoustic device to disperse the spectrum of a pulse-modulated CW carrier. The dispersed signal is itself modulated and then transmitted to a remote location, at low level. At the remote location, an acoustic device of conjugate characteristics is used to recover the dispersed signal from out of the background noise.

Abstract: A microstrip antenna design according to which a plurality of resonant frencies can be obtained for a given size radiator, to increase the usefulness of the antenna by providing for frequency diversity operation and by making the microstrip antenna tunable over a range of frequencies. As will be seen, the microstrip antenna is provided with an output termination which can be open-circuited or short-circuited, and at varying lengths, to change the frequency at which the microstrip antenna can be made resonant.

Abstract: It is taught that infrared light can be produced by applying a voltage to a semiconductor device with a superlattice region and, further, that a population inversion can be achieved in such a device so that infrared amplification and oscillation can be produced. Methods of producing infrared radiation and of amplifying infrared radiation utilizing semiconductor devices with superlattice regions are disclosed. Also, semiconductor devices with superlattice regions for use as a laser amplifier or oscillator are taught.

Abstract: A system for facilitating the training of a trainee to operate a target refinder. The system includes a slide (or film) projector for projecting a battlefield scene including one or more targets onto a viewing screen. The slide includes data annotated thereon corresponding to the range of the target; the target range is communicated to an operating console. A rangefinder simulator includes a means for generating a laser beam. In operation, the trainee sights the target, sets the range gate and fires the laser beam. When the laser beam hits the target, the console displays the proper range data which is then compared to the range set on the simulator by the trainee.

Abstract: A method and apparatus for determining anomalies in the frequency- or admittance-temperature characteristic of a piezoelectric crystal resonator by inserting a variable capacitance network in series with the crystal and electronically sweeping the value of the capacitance network by a control voltage applied thereto while the temperature remains constant and noting any abrupt change in the resonance frequency characteristic.

Abstract: An electro-optical system for determining the polarization state of optical pulses of nanosecond durations such as produced by lasers. This is achieved by using a six element optical polarizer assembly positioned in front of a six element optical detector assembly. The respective outputs of the six detectors are fed in predetermined arrangement to a plurality of operational amplifiers which are adapted to provide the sum/difference of the detector outputs for providing the Stokes parameters of an optical pulse incident thereto.