Abstract: A digital correction circuit for use in signal converters is disclosed. The invention includes a subtractor (32) for subtracting a digital correction signal from an input signal, a digital filter (34) for filtering the output of the subtractor to provide a digital output signal and memory (39) for providing said correction signal. In a specific embodiment of the invention, an improved analog-to-digital converter is disclosed including an improved digital-to-analog converter with digital correction circuitry.

Abstract: An integrated circuit structure and method of forming the same is described in which a plurality of common signal planes are provided for an integrated circuit formed on a layer of semiconductive material (30). The common planes consist of a single crystal semiconductive substrate (2) and at least one conductive layer (26, 66) between the substrate (2) and the semiconductive circuit layer (30), with insulative layers (24, 28, 68) separating the conductive layers (26, 66) from each other and from the substrate (2) and semiconductive layer (30). When one conductive layer (26) is used, a power supply signal (V+) is preferably applied to the substrate (2) and a ground reference to the conductive layer (26). Contacts are made between the integrated circuit and the desired common planes by metallized contacts (56, 60) formed in openings (54, 58) through the underlying material. Various circuit signals can also be introduced through additional conductive layers.

Abstract: The tone or polarity of a patterned layer such as a photoresist mask on an integrated circuit or device substrate is reversed with substantially perfect alignment. A liquid planarizing layer is formed and hardened onto the patterned layer and underlying substrate, filling in spaces between pattern areas. The planarizing layer is then etched to a sufficient depth to expose the patterned layer. Finally, the patterned layer is dissolved away, leaving the reversed tone image which is constituted by the planarizing material in the spaces which were filled in. Modified embodiments enable large spaces between original pattern areas to be effectively reversed, and multi-level reversed tone images to be formed in which the reversed tone layers are thicker than the original layers.

Abstract: A charge-coupled device (CCD) is provided with a dopant implant gradient, lateral channel stops and blocking implants by means of a focused ion beam (FIB). The FIB is repeatedly scanned across each cell of the CCD as a succession of overlapping but discrete implant scans. The doping levels of the FIB implants accumulate to a stepwise approximation of a desired dopant density profile, the widths of the steps being no greater than about half the widths of the discrete FIB implants. With a FIB pixel of about 750-1,500 Angstroms, the widths of the steps are preferably about 250-500 Angstroms; the dimension of the cells in the dopant gradient direction can be made less than about 5 microns. The lateral channel stops and back blocking implants can be as narrow as single FIB pixel widths, thus freeing up more of the cell for charge carrying capacity.

Abstract: A self-aligned, lateral bipolar transistor is disclosed having at least one insulated metal gate for control of the base. The device has a Semiconductor-On-Insulator structure that reduces parasitic capacitances. Proper gate control provides a high and controllable gain of the device and also turns off the parasitic transistors. The device achieves variable, high gains as well as high frequencies due to the use of the gate. It requires no masking or doping manufacturing steps in addition to those used in making standard CMOS circuits, and is CMOS compatible. In a preferred embodiment, a second insulated metal back gate is used to further enhance the operation of the device.

Abstract: A high speed digital programmable frequency divider (100) capable of frequency division by even and odd integers is disclosed herein. The frequency divider (100) of the present invention includes a waveform generator (200) for providing a periodic input waveform of a first period and the inverse thereof. The present invention further includes a clocked ring oscillator circuit (400) for providing first and second closed signal paths, in response to the input waveform, disposed to invert signals passing therethrough. The first and second signal paths have a common output node (499) and first and second propagation delays substantially equal to first and second integral multiples of the first period, respectively. In addition, the frequency divider (100) includes a programmable switch network (500) for opening the first and second signal paths to provide a periodic output waveform at the output node (499).

Abstract: An integral conductively-loaded encasing barrel for a slow-wave structure is formed by electrical discharge machining a plurality of circumferentially spaced longitudinally extending slots in the interior surface of the barrel. The machining discharge is established between a portion of the interior surface of the barrel and an electrode wire which is moved in a longitudinal direction within the barrel while the barrel is moved in a preselected manner in a plane transverse to the direction of movement of the wire. A subassembly comprising a slow-wave structure and a plurality of longitudinally disposed electrically insulating support rods in contact with and circumferentially spaced about the outer surface of the slow-wave structure is secured within the barrel with the support rods disposed within respective machined slots. The radially inwardly projecting portions of the barrel between the slots provide integral conductive loading for the slow-wave structure.

Abstract: Conical field emitter elements are formed on a surface of a substrate after which a layer of metal is deposited on top of the substrate surface and over the field emitter elements. A layer of oxide is then deposited over the metal layer. Another layer of metal is deposited over the layer of oxide to form a gate metal layer. A layer of photoresist is then deposited over the gate metal layer. The layer of photoresist is then plasma etched in an oxygen atmosphere to cause portions of the photoresist above respective field emitter elements to be removed and provide self-aligned holes in the photoresist over each of the field emitter elements. The size of the holes may be controlled by appropriately controlling process parameter, including plasma etching time and power and/or initial photoresist thickness. The exposed gate metal layer is etched using the layer of photoresist as a mask. The photoresist layer is removed, and the layer of oxide is etched to expose the field emitter elements.

Abstract: An adaptive optics system is disclosed which has a phase detector to detect phase distortions acquired by an input beam, and a separate phase adjustor which predistorts a transmission beam so that it is restored to its proper phase during transmission back through the same medium travelled by the input beam. The phase adjustor consists of a liquid crystal mechanism with an area substantially greater than that of the phase detector, thereby permitting high power operation. Liquid crystal pixels in the phase adjustor have dual transistor signal storage circuits which apply operating signals to the pixels without significant decay or flicker. The phase adjustor can be constructed in either a reflective or transmissive mode. Two phase adjustors may be placed in series to enhance response time and/or process an unpolarized beam. A data processor interfaces between the phase detector and phase adjustor.

Abstract: Regulation of an AC or DC voltage is achieved by processing a major portion of the prime power through a square wave inverter and a small portion of the prime power through a pulse width modulated switching regulator. The methods of regulation generally comprises the steps of: processing the unregulated input voltage to provide an output voltage; regulating an unregulated portion of the input voltage in response to a feedback signal indicative of the output voltage to provide a regulating voltage; and combining the regulating voltage with the output voltage to generate a regulated output voltage. The regulator circuit includes a square wave inverter circuit that produces a voltage in an output transformer, while a pulse width modulator regulates the output voltage in response to a feedback signal.

Abstract: A traveling-wave tube (10) has a confined-flow periodic permanent magnet focusing arrangement (26) in which either the first magnet (60f) or the third magnet (60t) from the electron gun (12) has an extent or axial thickness along the electron stream path which is one-half that of the remaining magnets in the arrangement, thereby providing a scalar magnetic potential of essentially zero on the electron gun pole piece (46), thereby eliminating the field reversal at the cathode (14). This enables a magnetic field to be provided in the region of the electron gun between the gun pole piece (46) and a location behind the cathode due solely to the magnetic field leaking through the gun pole piece aperture (50). The axial magnetic field within the electron gun (12) may be tailored or fine tuned, by varying the size of the aperture (50) in the gun pole piece (46).

Abstract: Disclosed is a device for making multi-layer crystals. It includes a holder and a plurality of masking elements adapted to be secured successively to the holder. The masking elements have cover pieces that overlie the area protected by the preceding cover pieces and have an additional cover piece. This produces a device having progressively truncated corner sections. There is thus formed a multi-layered crystal having portions adapted to be connected to electrical leads.

Abstract: A method for application of an adherent nickel plate to titanium includes steps of surface preparation, deposition of nickel from a plating solution, and a final treatment. The surface preparation steps include a hydrochloric acid dip, a nitric acid/hydrofluoric acid activation, treatment to slow the re-formation of an oxide layer, and deposition of a nickel strike. The treatment to reduce oxide formation may be accomplished without application of a current, in a solution of acetic and hydrofluoric acid, in which titanium alloy has been electrolytically dissolved. Alternatively, the treatment may be performed with the piece to be plated made anodic in a solution of acetic acid and hydrofluoric acid.

Abstract: A mercury compound such as mercury telluride or mercury cadmium telluride is deposited upon a substrate by chemical vapor deposition, with dissociation of the organic compounds accelerated by laser energy. The mercury-containing compound is preferably divinylmercury, which dissociates under intense light of 248 nanometers wavelength to deposit mercury in combination with the codeposited element. The laser-assisted chemical vapor deposition is accomplished at 100.degree. C. to 195.degree. C., preferably 165.degree. C., without the deposition of carbon contaminants.

Abstract: A field effect transistor FMCW radar transceiver for short-range target detection, employs a varactor-tuned, gallium arsenide field effect transistor, voltage-controlled oscillator in the dual role of the transmitter signal source and the local oscillator. The radar transceiver is capable of operating at low IF frequencies for short range, which can be less than 30 feet, target detection.

Abstract: A method is described for measuring the noise parameters of field effect transistors (FETs) while still in the wafer stage. Instead of conducting lengthy testing of each individual device at the operating frequency of interest after the devices have been diced, mounted and bonded, each of the devices on a wafer is automatically probed to obtain the standard S-parameters and also the FET's output noise power P.sub.n at a frequency at which parasitic probe effects are avoided. The various noise parameters can then be calculated for higher operating frequencies of interest from FET equivalent circuit parameters derived from the S-parameters, and from P.sub.n, either before or after dicing.

Abstract: A composite material having droplets of a liquid crystal material in a matrix of a coploymer of a multifunctional acrylate, or a mixture of different multifunctional acrylates, and a multifunctional mercaptan is prepared by photopolymerization. The liquid crystal material is initially mixed with a multifunctional acrylate monomer, a multifunctional mercaptan, and a photoinitiator to form a solution. The solution is exposed to ultraviolet light, whereupon the multifunctional acrylate monomer and multifunctional mercaptan copolymerize in a step reaction, and the liquid crystal separates from the copolymer as droplets dispersed throughout the copolymer matrix. The resulting material is placed between transparent, electrically conducting plates to form an electro-optic display device.

Abstract: A thermal engine is disclosed which is operable as a heat pump, refrigerator, or air conditioner. Vaporized working fluid from a first evaporator, which extracts heat from elements desired to be cooled, is fed to a first region of an osmotic pump which also has a second region containing a solution of the working fluid and a preselected solute, the second region being separated from the first region by a membrane permeable to the vaporized working fluid but not to the solute. A second evaporator, which may be driven by waste heat, is operatively coupled to the second region of the osmotic pump by means of a counterflow heat exchanger having a first path for conveying relatively dilute solution from the second region of the osmotic pump to the second evaporator and a second path for conveying relatively concentrated solution from the second evaporator to the second region of the osmotic pump.

Abstract: A motor winding assembly of mass M.sub.m is disposed for reciprocating linear movement within a housing, while a motor armature assembly of mass M.sub.a is disposed for reciprocating linear movement within the motor winding assembly. A first spring having a spring constant K.sub.m is connected between the motor winding assembly and the housing, and a second spring having a spring constant K.sub.a is connected between the motor armature assembly and the housing. The spring constants K.sub.m and K.sub.a satisfy the relation K.sub.m /K.sub.a =M.sub.m /M.sub.a, and since the motor housing assembly and the motor armature assembly move by amounts inversely proportional to their respective masses, essentially no vibration is transmitted to the housing over a wide range of motor operating frequencies.

Abstract: The disclosed multipactor device has a waveguide bandpass filter structure including a plurality of spaced pairs of opposing electrodes defining respective gaps therebetween in which multipactor action can occur in response to input microwave power in excess of a predetermined level. A radioactive source of beta particles provides electrons within the bandpass filter structure to ensure a very rapid commencement of multipactor action. The radioactive source includes a disk coated with a tritium compound and mounted in a transverse bore adjacent to the bandpass filter structure.