Abstract: This invention is a steerable thermoacoustic array system for directing information between an object that is above the surface of the water and a sound detector that is beneath the surface of the water. The foregoing system comprises a laser or particle accelerator that is located above the water's surface. The laser or particle beam produces a light beam or particle beam which contains information that is moved along a small layer of water at the air/water interface at a speed equal to the speed of sound in water divided by the steering angle of the laser so that the light beam or particle beam is absorbed by the water causing the water to expand and produce a series of acousitic Braves that constructively interfere with each other and travel towards the sound detector.

Abstract: The present invention provides a programmable image antenna formed on the face plate of a cathode ray tube (CRT) or on another substrate. The inner CRT face is coated with a silicon semiconductor material replacing conventional phosphors utilized in CRTs for generating visual images. An electron beam impinging upon the silicon-coated CRT face plate creates conductive areas during liberation of minority carriers, in the form of electron-hole pairs. Antenna elements having a virtually unlimited variety of shapes and/or sizes can be formed on the CRT face.

Abstract: A circuit for filtering single event effect (SEE) induced glitches is disclosed. The circuit for filtering SEE induced glitches comprises an SEE immune latch circuit and a delay element. The SEE immune latch circuit includes a first input, a second input, and an output. The SEE immune latch changes from one state to another state only upon having incoming input signals of identical polarity being applied contemporaneously at both the first input and the second input. The first input of the SEE immune latch circuit is directly connected to a signal input, and the second input of the SEE immune latch circuit is connected to the signal input via the delay element. The delay element provides a signal delay time equal to or greater than a pulse width of an SEE induced glitch but less than a pre-determined pulse width of an incoming signal at the signal input under normal operation.

Abstract: A method for manufacturing microscopic canals within a semiconductor is disclosed. A shallow trench is initially formed on a substrate using a patterned photoresist. After the patterned photoresist has been removed from the substrate, a separation layer, such as a Titanium layer, is deposited on the substrate. Subsequently, a cap layer, such as a Titanium nitride layer, is deposited on the separation layer. Both the separation layer and the cap layer are then polished off from the surface of the substrate. Finally, a Tungsten layer is deposited on the substrate and in the trench such that a microcanal will be formed within the trench as a result.

Abstract: This invention is a thermoacoustic system for communicating between an airborne or spaceborne vehicle and a sound detector that is located aboard an object beneath the surface of the water. The foregoing system comprises a laser or particle accelerator that is located aboard an airborne or spaceborne vehicle. The laser produces a light beam whose amplitude is subsequently modulated or whose pulses are varied in time. A particle accelerator would produce a pulsed particle beam that varies in time. These modulated or varied pulses are focused or deflected to a small layer of water at the air/water interface so that the beam will be absorbed by the water causing the water to produce an acoustic signal that will propagate to the sound detector.

Abstract: Two-photon absorption measurements are made at various points remote from monitoring apparatus by apparatus which includes two lasers that produce counter-propagating beams through the earth's atmosphere. The lasers are tuned such that the sum of the energies of the photons in each of the laser beams equals that associated with a predetermined transition of a gas in the earth's atmosphere. In one embodiment, a pulsed laser and a CW laser are used. The pulse from the pulsed laser propagates along the CW beam produced by the CW laser and overlaps the CW beam at positions determined by a range gating technique, which makes possible the measurement of the two photon absorption at the various positions of overlap or coincidence. In one embodiment, the subject apparatus is utilized for pollution monitoring, in which the frequencies of the lasers are tuned such that the energies of the photons from these lasers add up to a transition of a predetermined pollutant.

Abstract: A microwave imaging excavator for the detection, imaging and excavation of objects on or buried beneath the surface of the ground, such as metallic and dielectric land mines. A continuous wave stepped frequency ground penetrating radar signal is transmitted into the ground from a waveguide antenna mounted in one spade of a double spade auger. Direct breakthrough energy, signals reflected from the surface and the buried objects are received by an identical waveguide antenna mounted in the opposite spade. The spectra reflected from different buried objects become more distinct when the spectrum radiated spans the natural electromagnetic resonance of those objects. These signals are recorded as the twin-spaded auger is mechanically scanned over the ground in two mechanical rotational states of polarization. When the auger spades are on either side of a buried mine they are closed to grasp the mine which is then removed from the ground.

Abstract: The present invention features an improved cross-element meander line loaded antenna. Two pairs of triangle-shaped elements are each connected at their vertices to form bow-tie elements. The bow-tie elements are arranged orthogonally adjacent a ground plane, reducing shadowing and cross-coupling, and providing an efficient and compact meander lines antenna. When fed in quadrature, the antenna radiates a circularly polarized RF field having an excellent axial ratio.

Abstract: The present invention provides a reconfigurable diplexer which is well suited for use with mulitple element antenna arrays. The diplexer includes a common, slot-line transmission line adapted to carry electromagnetic signals; a pair a separate slot-line transmission lines coupled to the common transmission line; each separate slot-line transmission line having an individual filter coupled thereto, wherein each filter is adapted to selectively give its respective separate slot-line transmission line a characteristic impedance dependent upon predetermined frequencies of the electromagnetic signals; and a separate slot-line balun associated with each separate slot-line transmission line and adapted for coupling signals to and/or from its respective separate slot-line transmission line. The diplexer may be configured to operate in several different bands such as the INTELSAT frequencies (7.2-8.4 GHz) or DSCS frequencies (11.7-14.5 GHz).

Abstract: A meander line loaded antenna (MLA) that utilizes more two or more layers of meander lines to greatly extend the operating frequency range. The antenna of the present invention can achieve an operating frequency range of 100:1, unlike antennas of the prior art, which were limited to frequency ranges of approximately 10:1.

Abstract: A multiple spectral band opto-mechanical modulator for obtaining simultaneous but independent modulation of an extended IR source in two distinct wavelength bands comprises in one embodiment a first rotating filter wheel having alternating radial segments of transparent and short wavepass filter material, a second rotating filter wheel having alternating radial segments of transparent and long wavepass filter material, a stationary wheel having alternating radial transparent and opaque segments positioned intermediate the first and second rotating wheels and means for rotating said first and second filter wheels at predetermined frequencies.

Abstract: The present invention provides a single-event upset (SEU) hardened integrated circuit. The integrated circuit includes an SEU hardened asymmetric bi-stable CMOS latch having a first logic state and a second logic state. A supply voltage is operably coupled to the asymmetric bi-stable latch, where upon activation of the supply voltage the asymmetric bi-stable latch is always set to the first logic state. A switch may be provided for changing the latch from the first logic state to the second logic state.

Abstract: A compressive receiver including a dispersive delay line (10) and a frequency translator (16, 18) is preceded by signal compressors (22a-d) that record the incoming signals at one speed and play them back at a higher speed. This increases the frequency spread and provides greater frequency resolution at the output of the receiver.

Abstract: A clock splitter circuit for providing a Single Event Upset (SEU) tolerant clock signals to latches in a space-based environment. The splitter circuit includes an event offset delay. The event offset delay receives an undelayed clock signal and generates an undelayed inverted clock, a delayed clock signal and an inverted delayed clock signal. The delayed clock signal and the inverted delayed clock signal are delayed by the known duration of Single Event Effects (SEE) on logic. The delayed and undelayed clock signals are passed to a pair of event blocking filters which block any disturbance in the undelayed and/or undelayed clock signals. The event blocking filters each generate a pair of in-phase inverted output signals. The event blocking filters are designed such that both pairs of outputs may not be low simultaneously.

Abstract: The present invention features a cross-element, steerable, scanning meander line loaded (MLA) antenna with circular polarization. The transmission lines comprise a plurality of alternating or stepped impedance sections with the high impedance elements acting as active antenna elements. The impedance varies depending upon the spacing from the moveable ground plane. The orthogonal MLA elements allow the application of an in-phase and a 90° shifted signal, thus each linear array radiates a circularly polarized RF signal. Controlling the spacing between the ground plane and transmission line provides relative phase control between the active elements and thereby phased-array directional control of the antenna. Forming a two-dimensional array of these linear arrays, produces a compact, low-cost, scanning, phased-array antenna.

Abstract: A computationally efficient digital signal processing (DSP) system is provided for multiplexing/demultiplexing a large number of closely spaced FDM channels. Sub-band definition filtering divides the FDM channel band, comprised of N channels into K sub-bands, in order to reduce the dimension of polyphase filter fast-Fourier transform for completing the multiplexing/demultiplexing. This reduces the order of the required prototype by a factor proportional to K and allows small size, lightweight DSP implementations.

Abstract: A single-event upset tolerant sense latch circuit for sense amplifiers is disclosed. The single-event upset tolerant sense latch circuit includes a first set of isolation transistors, a second set of isolation transistors, a first set of dual-path inverters, a second set of dual-path inverters, and an isolation transistor. The first set of isolation transistors is coupled to a first bitline, and the second set of isolation transistors is coupled to a second bitline. The second bitline is complementary to the first bitline. The first set of dual-path inverters is coupled to the first set of isolation transistors, and the first set of dual-path inverters includes a first transistor connected to a second transistor in series along with a third transistor connected to a fourth transistor in series.

Abstract: In an integrated circuit package, the density of the I/O leads is increased by implementing the I/O leads by means of flexible circuits. Flexible circuits comprise thin sheets of insulating material on which the I/O leads are formed by photoetching. A conducting film is provided on the opposite side of the insulating film from I/O leads. To make the circuit package, the outer portions of the substrate of a quad pack are trimmed back to the contact pads on each side of the integrated circuit in the quad pack. The conductors of the flexible circuits are then soldered to the contacts of the contact pads.

Abstract: A single event upset hardened latch circuit is disclosed. The single event hardened latch circuit includes a first dual-port inverter and a second dual-port inverter. An input is coupled to the first dual-port inverter via a first set of pass gates. The first dual-port inverter is coupled to the second dual-port inverter via a second set of pass gates. The output is connected to the first and second dual-port inverters.

Abstract: A meander line loaded antenna provides a wide instantaneous bandwidth with a first planar conductor extending orthogonally from a ground plane, a second planar conductor substantially parallel to the ground plane and separated from the first planar conductor by a gap, a meander line interconnecting the first and second planar conductors across the gap, and a third conductor connecting the second planar conductor to ground. A fourth conductor provides enhanced capacitance between the first and second planar conductors. The antenna may be arranged in opposed pairs, and also as two orthogonally opposed pairs for enabling circular polarization.