摘要:
An apparatus determines the location of a signal source having coordinatesx,y). The source may be located as far away as two thousand km and does not require knowledge of ionospheric height or layer structure. The apparatus comprises at least three receivers adapted to receive the signals from the signal source. The coordinates, (x.sub.1,y.sub.1), (x.sub.2,y.sub.2) and (x.sub.3,y.sub.3), of each of the receivers are very precisely known. One receiver is capable of receiving signals from the other two receivers through different means (e.g. a wide-band telephone link). A plurality of at least three timers, one connected to each receiver, measures precisely the time difference of arrival (TDOA) of the signals from the signal source. A plurality of at least three means, connected one to each of the receiving means, determine the vertical angles .phi. at which the signal from the signal source is received by each of the receivers. More precisely, each receiver is in reality a phased array of individual antenna elements whose joint output can be used to measure both vertical angle and azimuth. Means are provided for calculating the coordinates (x,y) of the signal source from the measured vertical angles and the time differences of arrival.
摘要:
Formation of a plasma etch mask on a film on a substrate by photodecomposition of a gas at selective portions of the film's surface to deposit etch mask material and form the etch mask is disclosed. The photodecomposition by blanket illumination through a photomask and by direct write with a computer controlled laser are both disclosed. The formation of the etch mask can be immediately followed by the plasma etch without breaking vacuum.
摘要:
An apparatus and method for depositing a layer of a surface-compatible material from the gas phase onto a selected surface area of a substrate body using a plasma adjacent the substrate body to create a source gas which is decomposed by a laser or other source of energy on the selected surface area. The plasma-generated source gas may be varied by changing targets within the plasma or the reactant gases, and the laser energy may cause decomposition of the source gas by photolysis or pyrolysis or a combination of both.
摘要:
A beamforming apparatus is provided for processing the outputs of a linearrray of spaced apart receiving elements. The beamforming apparatus includes a surface acoustic wave device which has a pair of transducers mounted on a substrate in a spaced apart relationship. Each transducer is capable of receiving and converting an electrical chirp signal into an acoustic signal for propagation across the surface of the surface acoustical wave device. A plurality of taps are mounted on the substrate in a spaced apart relationship between the pair of transducers for receiving, sharing and converting the acoustic signals back into electric signals. Each tap is adapted to receive a bias voltage. A device is provided for mixing the signal from each tap with a signal from a respective receiving element so as to produce a plurality of mixed output signals, and another device is provided for summing the mixed output signals so as to provide a summed output signal. The summed output signal may then be processed by an upper sideband filter for controlling an indicating device. With this arrangement the beamforming is independent of the center frequency of the array from about 5 KHZ up to the millimeter frequency range.
摘要:
An apparatus is provided for processing the outputs of a two dimensional nar array of spaced apart receiving elements. The receiving elements are grouped and spaced apart in rows, which may be horizontal and vertical however, the rows may be in other directions provided they lie within a plane. The apparatus includes a plurality of surface acoustic wave (SAW) devices, each SAW device corresponding to a respective horizontal row of receiving elements and being capable of producing a plurality of horizontal phase shift outputs which linearly correspond to the number and horizontal spacing of receiving elements in a respective horizontal row. An additional SAW device is connected to the horizonatal SAW devices for introducing a vertical phase shift factor in the horizontal outputs of each horizontal SAW device so that each SAW device is capable of producing a plurality of combined phase shift outputs, the vertical phase shift factor corresponding linearly to the spacing of the receiving elements in a vertical direction. The apparatus further includes a mixer which corresponds to each horizontal SAW device for mixing the combined phase shift outputs with the respective outputs of the receiving elements in a respective horizontal row so as to produce a plurality of mixed output signals. If desired, the mixed output signals may be summed, processed by an upper sideband filter, and then fed to a video device. With proper controls of the horizontal and vertical scans of the video device two-dimensional imaging can be accomplished for indicating the direction and amplitude distribution of a radiating source with respect to the planar array of listening elements.With the present invention the beamforming is independent of the center frequency of the receiving element array from 5 KHZ up to the millimeter frequency range.
摘要:
A material suitable for the propagation of acoustic waves on its surface prises a substrate of semiconductor material, of which there exists an oxide, excluding the class of piezoelectric materials, the substrate having at least one flat surface. A layer of thermally grown oxide of the semiconductor material, is disposed on the flat surface. A film of titanium, approximately 300 angstroms thick, is disposed on at least a part of the layer of oxide. A layer of vacuum-deposited metal is disposed on the film of titanium. A layer of a piezoelectrid vacuum-sputtered material is on the layer of vacuum-deposited metal and on the oxide. The semiconductor material may be silicon, the oxide may be silicon dioxide, the piezoelectric material may be zinc oxide, and the metal may be gold. The material further comprises an interdigitated electrode structure disposed upon the piezoelectric material, which, when an electrical signal is applied to it, can cause propagation of a surface acoustic wave (SAW) upon the surface of the piezoelectric material, the combination comprising a SAW transducer.
摘要:
Planar superconducting-normal-superconducting (SNS) Josephson microbridgesnd superconducting quantum interference devices (SQUIDs) with bridge widths of about 0.2 microns and lengths of about 0.1 micron or less are fabricated with the aid of a technique referred to as "shadow evaporation". The procedure permits the submicron dimensions to be set by edge film thickness and slant evaporation angle, both of which can be accurately measured. Microbridges have been constructed with vanadium banks or electrodes and gold-titanium bridges, although other materials can be used including superconducting metals for the bridge. It is expected that a refined version of this technique would be suitable for repeated batch fabrication of single and multiple Josephson microbridges.
摘要:
A method of fabricating lines of submicron width, comprising the steps of:providing a substrate,depositing a first layer of metal upon the substrate;spinning a photoresist layer on the metal;patterning the photoresist layer;etching the metal to undercut the photoresist edge, e.g. with a mixture for approximately ten minutes at room temperature;depositing a second layer of metal at an angle .theta..sub.1 to the photoresist edge, thereby defining a long, submicron-wide opening to the underlying substrate;depositing a chosen material, for example, metallic or semiconductor, for the bridge onto the substrate at an angle of .theta..sub.2 through the submicron-wide opening; andremoving undesired material surrounding the bridge by dissolving the photoresist in hot acetone followed by stripping the remaining two layers of metal with etchant.
摘要:
An apparatus and method are provided for depositing submicron patterns on a substrate. The apparatus includes an evaporative source located opposite the substrate so that molecules from the source can be deposited directly on the substrate. A mask is located between the evaporative source and the substrate, the mask having openings which correspond to the desired pattern to be deposited on the substrate. A plate is located between the mask and the substrate, the plate having an aperture for allowing evaporated molecules to be deposited on the substrate according to the pattern of the mask.