Abstract: The apparatus/method according to the present invention accomplishes a reduction in the total number of direct digital synthesizers (DDSs) needed for use in electronically scanned antenna array to generate multiple simultaneous radio frequency (RF) beams. The apparatus includes, inter alia, a multi-beam forming synthesizer, a plurality of DDSs, a corresponding plurality of amplifiers all operatively connected to a plurality of radiating elements of the antenna array. This arrangement uses a single DDS per radiating element. Each DDS uses a composite amplitude, phase and frequency information computed by the multi-beam forming synthesizer to create the proper waveform for driving the antenna array, and accordingly, generating the desired multiple simultaneous RF beams, i.e. 1-M (e.g. 1 through M) RF beams each of which can have a different frequency and separate modulation.

Abstract: A new type of atom guiding structure has been analyzed. It consists of a low-core optical fiber (step-index) which is not clad, but instead has a metal coating on its outer lateral surface. It will be shown that this structure produces the maximum evanescent field in the hollow region of the fiber and guiding can be accomplished with lower power lasers. Both the dipole and the vander Waals potentials have been combined and the resulting barrier height was maximized as a function of both .DELTA., the detuning, and r, the position. An optimized potential having a barrier height of 1 K has been determined by iteratively solving for the required laser intensity. The probability of atoms tunneling through this barrier to the inner wall has been calculated and is expected to be unimportant. Centripetal effects due to a bending of the fiber have also been estimated and are small for the barrier considered here.

Abstract: Polymer materials having a low Young's modulus, a low dielectric constant, and a high apparent piezoelectric response when subjected to a high direct bias voltage and a superimposed alternating voltage, used as the active element in an underwater acoustic signal projector of a sonar system.

Abstract: A broadband, traveling wave amplifier which includes a target anode and an lectron gun for bombarding the anode with an electron beam having an amplitude proportional to that of an input signal. The electron gun includes a NEA semiconductor cold cathode having an electron emitting surface and a modulation structure for modulating the emitted electron beam with an input signal to be amplified. The electron gun and the anode are configured as parallel strip transmission lines having the same phase velocity. The target anode may be a reversed-biased stripline diode, Schottky barrier stripline diode, or metal/semiconductor/metal stripline structure.

Abstract: A method of detecting/identifying organic molecules which have been mixed th an appropriate electrolyte to form an electrolytic solution is disclosed. The organic molecules to be detected/identified are adsorbed onto the surface of a conducting substrate, which is adjusted to an overall positive voltage potential within a range of E.sub.LOW and E.sub.HIGH. The voltage potential on the surface of the conducting substrate, and, accordingly, the adsorbed organic molecules, is adjusted until an electrochemically-induced change occurs. The voltage potential at which the change occurs is characteristic of the organic molecule, thus permitting detection/identification thereof.

Abstract: A six-pole band-pass filter system and circuit configured for optimal permance in an associated infrared search and track (IRST) system which outputs data in an analog format is disclosed. The key to the successful operation of the filter is its matching to the impulse response of the associated IRST system. By adjusting certain components in the filter, it can operate as an optimal, linear, one-dimensional device to detect unresolved targets against a severely cloud-cluttered background.

Abstract: A vertically integrated DRAM cell having a storage time of at least 4.5 hours at room temperature, formed from a wide-bandgap semiconductor such as GaAs or AlGaAs, in which an n-p-n bipolar access transistor is merged with a p-n-p storage capacitor, with the middle p-n layers being common to both. Similarly, a p-n-p transistor can be merged with an n-p-n storage capacitor.

Abstract: A heterojunction bipolar transistor (HBT) structure is configured so that the heterojunction between hexagonal and cubic materials is electrically active. A first embodiment of the HBT structure comprises both hexagonal and cubic silicon carbide (SiC). The emitter region is fabricated from the higher bandgap hexagonal SiC appropriately doped. The base and collector regions are grown using the lower bandgap cubic SiC. A second embodiment of the HBT structure comprises both a solid solution of SiC material such as an alloy of silicon carbon aluminum nitrogen (SiCAlN) grown upon a substrate of hexagonal SiC. The emitter region can be placed either on the top or bottom of the second embodiment of the HBT structure. Also, the bandgap between the emitter and base regions of the second embodiment can be varied by controlling the mole fraction ratio between the constituent parts of the SiCAlN, i.e., between the SiC and the AlN.

Abstract: Both homojunction and heterojunction bipolar transistor structures are fabricated in unique trenched configurations so as to better utilize their surface areas by employing both the vertical and horizontal portions of their base regions with equal effectiveness. An important advantage of the unique trenched configurations is that the base region of each trenched structure is of precisely the same thickness throughout--both vertical and horizontal portions. Consequently, the transit time for charge carriers to diffuse across the base region and the base transport factor are uniform because of the uniform base thickness. Moreover, the parasitic capacitance region of each trenched structure beneath base metallization contacts is only a small portion of the entire base-collector junction region.

Abstract: An apparatus for and a method of growing thin films of the elemental semiductors (group IVB), i.e., silicon, germanium, tin, lead, and, especially diamond, using modified atomic layer epitaxial (ALE) growth techniques are disclosed. In addition, stoichiometric and non-stoichiometric compounds of the group IVB elements are also grown by a variation of the method according to the present invention. The ALE growth of diamond thin films is carried-out, inter alia, by exposing a plurality of diamond or like substrates alternately to a halocarbon reactant gas, e.g., carbon tetrafluoride (CF.sub.4), and a hydrocarbon reactant gas, e.g., methane (CH.sub.4), at substrate temperatures between 300 and 650 Celsius. A stepping motor device portion of the apparatus is controlled by a programmable controller portion such that the surfaces of the plurality of substrates are given exposures of at least 10.sup.15 molecules/cm.sup.2 of each of the reactant gases.

Abstract: An apparatus for and a method of growing thin films of the elemental semiconductors (group IVB), i.e., silicon, germanium, tin, lead, and, especially diamond, using modified atomic layer epitaxial (ALE) growth techniques are disclosed. In addition, stoichiometric and nonstoichiometric compounds of the group IVB elements are also grown by a variation of the method according to the present invention. The ALE growth of diamond thin films is carried-out, inter alia, by exposing a plurality of diamond or like substrates alternately to a halocarbon reactant gas, e.g., carbon tetrafluoride (CF.sub.4), and a hydrocarbon reactant gas, e.g., methane (CH.sub.4), at substrate temperatures between 300 and 650 Celsius. A stepping motor device portion of the apparatus is controlled by a programmable controller portion such that the surfaces of the plurality of substrates are given exposures of at least 10.sup.15 molecules/cm.sup.2 of each of the reactant gases.

Abstract: A simulated burst echo signal (artificial target), corresponding to a deld and conditioned version of an RF burst signal from an associated radar under test, is presented to the associated radar under test by coupling a portion of the RF burst signal into a shipboard sensor exerciser apparatus in which the present invention is employed to feed an attenuated facsimile of the RF burst signal into a phase-locked loop portion thereof. The phase-locked loop locks on to the attenuated facsimile of the RF burst signal and generates an error signal in response thereto. The error signal is then digitized and stored in an error storage unit portion where it is delayed for a predetermined time associated with the desired selected range of the artificial target.

Abstract: A monitor determines, from the ground, the orientation (roll and attitude) f a missile by observation of the character of a transmitted signal(s) therefrom. By transmitting to a ground receiver a linearly polarized signal(s), the missile identifies a given plane fixed with respect to its body frame. This plane is identified at the ground receiver by comparing the ratio of the signal(s) received in any two cross-polarized directions. To resolve the attendant 180.degree. ambiguity, the monitor employs an antenna array disposed on the missile that is switchable, back and forth, between two equal power lobes. The monitor operates with a single transmitter, and the simple lobe structure of the transmitted signal(s) is obtained using a linearly polarized antenna array with electronic phase switching between the aforementioned equal power lobes.

Abstract: A clutter suppressor/target locator apparatus is configured to manipulate rget video data on a particular channel according to a predetermined algorithm, so as to selectively emphasize those area of a scene containing targets of appreciable contrast to the background and de-emphasize those areas where the brightness levels change gradually from point to point. The algorithm takes into account points ahead and behind the point or picture element being tested, and also equal points or adjacent channels. The apparatus is substantially free of false alarms, and the unique configuration thereof allows detection of the presence of a target on an extremely rapid basis.

Abstract: A communications interface and system is configured to allow circumvention recovery of control after radiation) of a microprocessor portion thereof. The communications interface portion, including a hard memory interface device serves as a communications link to the microprocessor. The system is configured so that a transient upset from prompt gamma radiation is detected and a circuit freeze of the stored information in the system is carried out until the transient subsides. The system then restores the microprocessor to the preirradiation condition and resumes operation. Accordingly, the hard memory interface device of the communications interface, controls a READ operation and CLEAR and WRITE operations in addition to generating signals to control the "handshaking" between the hard memory of the communications interface and the aforementioned microprocessor.

Abstract: An intensity measurement system portion of a phase measurement and control ystem permits rapid measurement of the laser field intensity profile in the transverse plane of a main laser beam. The intensity measurement system portion measures the laser field intensity profile by measuring the intensities of a plurality of beam samples of the main laser beam. The aforementioned measured intensities are processed in a phase computer according to a predetermined algorithm to generate drive current profiles in response to the phase variations of the main laser beam. These drive currents a dither-control amplifier which causes electromechanical movement of a plurality of mirror segments of a multi-dither mirror to correct for the random phase variations in the main laser beam.

Abstract: A test set including a digital card tester section and a satellite simulator section is used to detect the reduced capabilities of an associated navigational satellite receiver and to isolate malfunctions therein. The digital card tester section is configured to generate digital signals (signatures) which are used to test and isolate faults in four digital system boards (cards) of the associated navigational satellite receiver. The satellite simulator section is configured to generate a facsimile of a navigational reference signal which is normally transmitted by an associated satellite system and received by the aforementioned associated navigational satellite receiver. The facsimile signal is used to test the receiver-processor section of the associated navigational satellite receiver.

Abstract: A pulsed laser beam aiming apparatus is configured such that substantially 00% of the energy from a pulsed laser beam from a Q-switched pulsed laser device is accurately aimed at a distant target/obstacle in space. The pulsed laser beam is reflected off of a multifaceted polygonal mirror spinning about its axis and perpendicularly affixed to a rotatable azimuthal table wherein the spinning mirror provides elevational orientation, and, in conjunction with the rotatable azimuthal table, azimuthal orientation. Control circuit and associated equipment cause the Q-switched pulsed laser device to be triggered on when a facet of the mirror is in the proper elevational and azimuthal orientation for the pulsed laser beam to hit the target/obstacle. Correct aiming of the pulsed laser beam at the target/obstacle is accomplished when the coordinates thereof are specific only as an elevational angle .+-.5 above and/or below the horizon and an azimuthal angle between 0.degree. and 360.degree..

Abstract: An enhanced random access memory element and a process for its fabrication, herein permalloy thin films are patterned, inter alia, into a plurality of geminous memory cells to form a matrix or array of juxtaposed sloped columns thereof is disclosed. Each of the geminous memory cells is configured into a unique pattern comprising twin sub-patterns joined in an opposite fashion, i.e. reversed and inversed, so as to share a common area of permalloy. Consequently, magnetic domain walls (Neel walls) are formed at opposite and adjacent apexes of the unique pattern parallel to the easy axis after a predetermined magnetic field is applied along the hard axis of the array of geminous memory cells and then reduced to zero. In this way, the magnetization is properly aligned for use of the array of geminous memory cells as an enhanced nonvolatile random access memory element.

Abstract: A compass system and method incorporating a global positioning system (GP such as the NAVSTAR/GPS multi-satellite system, is configured to acquire accurate compass heading information without being affected by magnetic anomalies and without being dependent on the elapsed time since a previous position fix. The compass system comprises, inter alia, two antenna/preamplifiers located, for example, fore and aft a ship or aircraft separated by a predetermined distance d. A microprocessor/minicomputer portion of the system causes an electronic coaxial switch to switch a GPS receiver between the two antenna/preamplifiers automatically thereby measuring their absolute positions. The microprocessor/minicomputer computes and displays on a display unit a compass heading based on the knowledge of the absolute positions of the antenna/preamplifiers and the distance d therebetween.