Abstract: An additional layer of electrically insulating material is added to the backside of thin wafers, especially wafers made from brittle semiconductor material such as gallium arsenide and comprising integrated circuits of, for example, the microwave monolithic integrated circuit type. The added layer of material is used to add mechanical rigidity and abuse tolerance to the otherwise quite fragile wafer, and is especially useful during probe testing of circuit die located on these fragile wafers and in the steps preceding and following probe testing. Preferably, the added layer is made from silicon nitride or silicon dioxide, or one of several diamond-related materials. The former materials provide the advantage of ready availability, low cost, and possibly already accomplished use in the wafer's fabrication; the latter diamond-related materials have the significant advantages of notable hardness, along with desirable heat conducting properties.

Abstract: A method for fabricating a liquid conducting porous article having micron sized metallic particles suspended on a ceramic substrate member. The method includes coating the ceramic substrate with a particle slurry on top of which is added an additional amount of the same particles as a dry powder, and then heat treating the article in a reducing gas atmosphere. The use of less than ten micron sized Nickel particles for the porous material and sintered fusion of the particles are also included.

Abstract: A high energy level arrangement for generating microwave frequency electromagnetic energy from a DC power source by way of a high energy level electron beam coupled into an output waveguide member and serving therein as an antenna source of energy for the waveguide member. The electron beam is preferably spatially and timewise modulated with sinusoids to improve conversion efficiency to dominant mode waveguide energy. The disclosure includes several embodiments including a waveform splicing arrangement and plural electron gun embodiments and discloses quantitative efficiency and operating voltage level data. Use of the invention in weaponry, radar, deep space communication and other high radio frequency level energy applications is also disclosed.

Abstract: An integrated aircraft power unit providing the electrical and other forms of energy needed during auxiliary power unit operating conditions-while the aircraft is on the ground, and also providing airborne or emergency power including high altitude flight emergency conditions power wherein the power unit uses an oxidant supply carried by the aircraft. In this high altitude operating condition the power unit provides lower electrical output, but lower losses and improved efficiency over previous power units. The disclosed power unit includes separate electromechanical transducers or motor generator devices coupled to a segregated pair of rotational shaft members, one for the inlet or compressor fan and one for the outlet or exhaust turbine fan with electrical coupling and then friction clutch coupling of these shafts accomplished for low altitude high energy output operation of the power unit.

Abstract: A high energy level electronic device is segregated into source diode and utilization diode portions, portions which may also be identified as cathode and main diode portions, respectively. The cathode diode portion is operated at a low voltage such that closure velocity effects therein although present, are minimized. A current of electrons, generated by in cathode diode plasma is fed to the second diode through an anode screen portion of the cathode diode. In this arrangement, since there are electrons, but no plasma cathode present in the main diode, no closing problem occurs therein. In this arrangement, therefore the cathode diode is effectively a source of current for the main diode and is operated at minimal voltage to enable the provision of current for a maximum length of time prior to closure effect terminations.

Abstract: A passive distance measuring system for aircraft landing or other transportation related or other general usage is disclosed. The passive system operates by measuring the time interval between arrival of a precision sweep scanned signal such as a radio frequency signal at two widely dispersed different signal receptor locations on the aircraft. By knowing the angular sweep velocity of the received signals and the receptor or antenna separation distance on the aircraft, the distance of the aircraft from the scanning source of, for example, radio frequency signals may be computed with appreciable precision. The disclosure includes analog-to-digital signal conversion and modifications of the invention including optical or laser signals in lieu of the preferred microwave radio frequency signals. The disclosure also includes a table of numeric values relating pulse separation time to aircraft range distance and indicates a number of equipment and military environment advantages of the invention.

Abstract: An arrangement for achieving reliable communication of perceived attitude information from the test subject in an environmentally controlled spatial disorientation study. The communications system includes a talking with the hand protocol wherein the orientation of the test subject's opened hand is sensed upon command from test monitoring persons. Orientation of the test subject's hand is remotely sensed by way of a three-axis of rotational freedom transducer apparatus in which the test subject's hand is suspended in a manner providing minimal orientation feedback to the test subject. Use of the described system includes a selection of additional physiological influencing environmental inputs for the test subject including visual and audible stimulus information.

Abstract: A superconducting optically reconfigurable device (SORD) wherein predetermined and optically achieved patterns of superconducting material generate Meissner effect magnetic flux to achieve control of physical characteristics in local areas of an adjacent film of electromagnetic energy controlling material. The superconducting material magnetic flux is remembered by way of a cycle wherein selected portions of the material are elevated from the superconducting temperature range through the critical temperature T.sub.c into the non-superconducting state while in the presence of a writing magnetic field and then cooled through the critical temperature T.sub.c to permanently retain the writing magnetic flux in the area of temporary optical warming. The pattern of magnetic flux thusly achieved is coupled to one of several possible electromagnetic energy influencing or controlling materials which also have magnetic flux susceptibility.

Abstract: A multiple quantum well arrangement which achieves significantly improved third order optical nonlinearity in a semiconductor device by way of spatially periodic electrodes applied to the semiconductor device. The spatial period of the applied electrodes and the resulting exciton confinement dimension is improved over that of previous multiple quantum well structures and to the Bohr radius range of dimensions for the semicondcutor material by way of avRIGHTS OF THE GOVERNMENTThe invention described herein may be manufactured and used by or for the Government of the United States for all governmental purposes without the payment of any royalty.

Abstract: A binary add signal selection type wherein carry signals rather than the usual sum signals are selected from presumed signals by multiplex switching in each bit slice cell of the adder. The new adder is organized into propagation delay time determined stages which include a plurality of sub-stages of multiple bit slice cells each with the carry signals from a previous stage performing the multiplex carry-selection in each stage. The resulting adder is of regular circuit form and adapted to modern fabrication techniques including VLSI and standard cell. arrangements. Mathematical and graphic comparison of the new adder with plural existing adder architectures are included.

Abstract: A field emitting drain field effect transistor FEDFET device which combines the desirable frequency response and current control characteristics of a field effect transistor (or other transistor) with the higher voltage higher power level characteristics of a field emission triode vacuum tube device to provide characteristics improved over those of either component element. The combination device is physically as well as electrically integrated in a semiconductor like structure. Equivalent circuit and frequency response characteristics are disclosed.

Abstract: A superconducting network which, through the use of optical illumination, can form a selectable array of superconducting microstrip transmission lines or other electrical elements. The invention uses optical illumination to produce quasiparticles which cause selected physical parts of the network to be electrically nonconductive and thereby define the nonilluminated conductor's shape, physical size, and electrical characteristics. Network reconfigurability to produce several different devices and functions from a single high or low temperature superconductive chip is a disclosed utilization of the invention. The employed optical illumination produces phase change within the superconducting material to provide specific chip architectures. Reconfiguring of the device characteristics is achieved by changing the optical input intensity, spatial orientation, wavelength or combinations of these factors. A plurality of delay line configurations are disclosed as examples.

Abstract: A binary adder of the carry multiplex signal selection type wherein multiple levels of multiplexing between parallel carry paths is used to achieve improved adder performance as measured by adder fabrication area requirements and other performance criteria. The resulting adder employs a plurality of different adder stages of successively increasing complexity and achieves performance time that can be characterized as being of the order of Log.sub.2 (n), wherein n represents bit count, and as requiring a gate count that is of the order of n. Both internal arrangement of the adder stages and interconnection arrangements therefor are disclosed.

Abstract: A time indexed voice recording system wherein tone coded time signals are received on one channel of an entertainment grade stereophonic tape recorder and the desired voice signals entered into the other channel. The recording system is portable in nature and especially adapted for use in airborne missions where it can be placed within the clothing of an aircrewmember in even the smallest of aircraft cockpits. The tone code in the disclosed system is generated by a telephone compatible microcircuit system which also includes a microcomputer and software for system controlling purposes. The disclosure includes a flow diagram of the microcomputer software as well as a complete assembly language listing.

Abstract: An aircraft attitude display format which maintains the horizon reference line always in view and which presents the pilot with multiple indications of aircraft attitude differing from level flight. The multiple indications include attitude registration along an angular scale and shape change of the horizon reference line. The display format has the appearance of a fish-eye lens derived optical image and is preferably placed in this form by electronic image processing--which is exemplified by an included mathematical discussion and computer code listing software. Provisions for other data display are also disclosed. Use of the display format in a panel instrument or CRT-based system including the HUD configuration are contemplated.

Abstract: An improved commutation arrangement for an AC to AC or AC to DC energy converter circuit is disclosed. The improved arrangement uses turn-off capable commutation switches to enable modification of the operating waveforms in the cycloconverter. The modified waveforms include an operating concept wherein in lieu of always switching to the next lagging phase (as is done with conventional cycloconverters), an intervening switch is made to the leading phase when the output voltage is less than one-half of the maximum value. The disclosure includes mathematical consideration of source machine power factor, output waveform ripple content, interphase transformer characteristics, engine starting usage, and other refinements of the commutation arrangement.

Abstract: A mechanical-to-electrical transducer arrangement wherein a combination of signal preamplifier and programmable analog signal processing circuitry is disposed immediately adjacent the transducer's sensor cell where low losses a low noise coupling into the signal path can be achieved. The programmable analog processing includes differentiation, filtering, integration, amplification and elective disconnection of the sensor cell to enable rapid transient signal recovery. Provisions for generation of transducer identification code and test signals in the processing circuitry and communications by way of a two wire time shared communication path is included.

Abstract: Multibeam coupling in a Kerr medium of nonlinear characteristics and finite response time is disclosed together with two different frequency spectrum examples of its use. In the first spectrum example, the modes are equally spaced and in the second spectrum the frequency separations are all unequal. In either case, as the beams propagate, both input spectra eventually reach a saturation characterized by a cascading of energy into the lowest frequency if the Kerr constant is positive. The direction of cascading of energy transfer is reversed to the highest frequency if the Kerr constant is negative. The examples disclosed include a typical Kerr medium and are representative of a multimode, equally spaced laser source and an unequally spaced source. For the equally spaced case, the optimum medium response time for conversion of Gaussian spectra is disclosed. If the frequencies are unequally spaced general conditions to be satisfied are disclosed, along with examples.

Abstract: A pulsed laser illumination based one camera ranging and imaging system which requires only a single axis optical aperture and is therefore suited to use on aircraft and other space and configuration limited apparatus is disclosed. The invention uses intensity coded partial images of the distant target in a single camera with the partial images being obtained by a distance segregating optical modulation arrangement which separates pixel portions according to their arrival time and thereby the distance of travel from the target. The described system uses pixel by pixel processing of the segregated images as accomplished in an image array processor, for example.

Abstract: A multiple energy level, multiple pulse repetition frequency, common boresight laser energy source apparatus which employs phase conjugate energy reflection, achievable in a high-pressure gas retro-reflecting cell, to compensate for aberrations of the energy beam occurring in other optical elements. Use of the multiple energy level source in military, medical and industrial settings is described with the lowest level output energy being "eye-safe" for use by operators performing preliminary positioning and alignment of the source. The disclosure includes description of embodiment element limitations and identifications of alternate elements usable to overcome these limitations. Parallel and serial dispositions of the optical elements and discussion of advantages and limitations incurred thereby is also included.