Abstract: The present invention relates to an apparatus for measuring the capacitance and the dissipation factor in a transformer bushing and extracting gas dissolved in the insulating fluid of said bushing. The apparatus comprises a porous cylindrical member associated with a tap connector and covered by a thin layer of a gas permeable but liquid impermeable membrane. The porous member allows passive diffusion of the permeated gas extracted from the insulating fluid of a transformer bushing to a gas storage chamber for further analysis, thereby helping to prevent high costs related to damage or destruction of the bushing.

Abstract: Combined Vivaldi notch and meander line loaded antennas are concatenated in an array to provide an ultra wideband antenna having a decreased low frequency cut-off due to the concatenation. In the concatenation process, plates of adjacent antennas are shared so that one plate is used for both of the adjacent antennas. In a preferred embodiment, the side plates and the top and bottom plates are identically configured.

Abstract: The present invention provides a broadband RF absorptive structure based on a classic Salisbury screen. Closely-spaced frequency selective surface reflective layers interact with a ground plane to reflect coherent signals at 377&OHgr; into a spacecloth front layer. The frequency response of the absorptive structure is relatively flat across an octave (i.e. a 2:1 frequency ratio) bandwidth. The overall thickness of the inventive structure is less than &lgr;/4 thickness of the interactions of the FSS layers and the ground plane.

Abstract: The present invention provides a low-cost, frequency-tunable, steerable, reflector array capable of simulating the electromagnetic effects of a parabolic or similarly-shaped reflector on a planar or conformal surface. Simple scatterers such as short circuited dipoles, disposed on a geometrically planar or conformal substrate, are configured from a series of scatterer sub-elements, electrically connected serially to one another by MEMS switches. These connected scatterer sub-elements form a reflective array disposed above a ground plane on the substrate. By properly controlling the length and spacing of the activated dipole elements, it is possible to simulate the equiphase reflection profile of a horn feed or sub-reflector feed of a parabolic or similar reflector. In addition, the array may be steered by selectively controlling the scatterer configurations.

Abstract: An oil, such as a mineral oil, for example, transformer oil, is contacted with calcium carbide and the mixture is stirred until a liquid phase containing less than 1 ppm water and a solid phase containing Ca(OH)2 and unreacted CaC2 are obtained. The oil obtained can be used to give samples of known quantities of water by adding corresponding amounts thereto.

Abstract: The present invention provides a low-cost, steerable antenna formed with a dielectric medium separating a pair of conductive plates and a centrally located signal feed. Switches selectively interconnect the conductive plates through the dielectric medium in patterns, which determine the direction of operation of the antenna. The directionality of the antenna may be fixed or rapidly changed, depending upon the application.

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: 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: The present invention provides a low-cost, steerable antenna formed with a dielectric medium separating a pair of conductive plates and a centrally located signal feed. Switches selectively interconnect the conductive plates through the dielectric medium in patterns, which determine the direction of operation of the antenna. The directionality of the antenna may be fixed or rapidly changed, depending upon the application.

Abstract: The present invention provides a low-cost, frequency-tunable, steerable, reflector array capable of simulating the electromagnetic effects of a parabolic or similarly-shaped reflector on a planar or conformal surface. Simple scatterers such as short circuited dipoles, disposed on a geometrically planar or conformal substrate, are configured from a series of scatterer sub-elements, electrically connected serially to one another by MEMS switches. These connected scatterer sub-elements form a reflective array disposed above a ground plane on the substrate. By properly controlling the length and spacing of the activated dipole elements, it is possible to simulate the equiphase reflection profile of a horn feed or sub-reflector feed of a parabolic or similar reflector. In addition, the array may be steered by selectively controlling the scatterer configurations.

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 wood article is submitted to a vacuum in an autoclave to remove air that it contains. Then, a solution which contains a water-soluble cross-linkable prepolymer, a polymerization initiator and optionally a wood preservative is introduced into the autoclave. Polymerization to form a polymeric network in the wood article is carried out in an atmosphere which may be substantially free of oxygen, while the optionally present preservative is chemically fixed to the wood. The result is a wood article with a permanently reduced hardness and an increased moisture content at equilibrium.

Abstract: A wood article is submitted to a vacuum in an autoclave to remove air that it contains. Then, a solution which contains a wood preservative, a water-soluble cross-linkable prepolymer and a polymerization initiator is introduced into the autoclave. Polymerization to form a polymeric network in the wood article is carried out in an atmosphere substantially free of oxygen, while the preservative is chemically fixed to the wood. The result is a wood article with a permanently reduced hardness and an increased moisture content at equilibrium.

Abstract: Preservatives and oil are extracted from treated wood. For this purpose, treated wood that is intended to be discarded is comminuted, the chips are impregnated with an alkaline solution until softening of the chips and modification of the chemical state of the products to be extracted. Possibly, the chips may be treated with saturated steam at a temperature between 170.degree. C. and 210.degree. C. followed by an explosive decompression giving wood fragments. This is followed by a refining operation in a crusher permitting the grinding of the wood. The result is a substantial release of the preservatives and oil from the wood chips which are at least partly disintegrated. The chemical preservatives and the oil are collected separately from the wood chips in the aqueous phases which are produced in the impregnation, steam cooking-explosive decompression and refining steps.

Abstract: A microstrip tee-fed slot antenna is made up of only a single printed circuit board having the tee feed and slot on the front side and a microstrip transmission line feed on the back side. A plurality of holes in the board surrounding the slot are electrically connected front to back to provide the antenna cavity. Since only a single board is used having all of the components of the antenna on either side, no disassembly is required to add to or modify the elements of the antenna.