Abstract: A plurality of TEM mode transmission lines (L2-L5) are structured by pairs of thin film conductors (21 and 22, 22 and 23, 23 and 24, and 24 and 25) which sandwich thin film dielectrics (31 to 34) by alternately stacking the thin film conductor (21 to 25) and the thin film dielectric (31 to 34). The phase velocities of TEM mode waves which are propagated at least by two of the transmission lines (L2 to L5) are substantially equal to each other. The thickness of each of the thin film conductors (21 to 25) is smaller than the skin depth of the frequency used so that the electromagnetic fields of at least two TEM mode transmission lines among the TEM mode transmission lines (L2 to L5) are coupled to each other. In this way, the skin depth can be increased effectively. The conductor loss and the surface resistance can be reduced significantly as compared to those of the conventional electrode. By use of this electrode, a transmission line, a resonator, a filter, and a high frequency device are structured.

Abstract: An insulated wire with a noise-suppressing function includes a ring-shaped magnetic core, a coated wire inserted into the hole of the ring-shaped magnetic core, and a securing member for securing the ring-shaped magnetic core to the coated wire. The inner diameter of the ring-shaped magnetic core, namely the diameter of the hole, is set smaller than the outer diameter of the coated wire. The coated wire is formed of a pair of parallel conductive wires, a wire-coating member for coating the pair of conductive wires, and a sheath for covering the wire-coating member. The sheath is removed at one end of the coated wire. A part of the conductive wires which is coated only with the wire-coating member is inserted into the hole of the ring-shaped magnetic core.

Abstract: An RF connector includes an electrical insulator having an aperture and a conductive contact disposed within the aperture and having at least one compliant, compressible end. The insulator is disposed in an aperture of a conductive support plate. When an RF element is secured to the support plate in use, the compliant end of the conductive contact is compressed against a conductive pad of the RF element. In one embodiment, the RF connector includes a compressible, conductive annular ring disposed concentrically around the compliant end of the conductive contact and adapted for being compressed against a ground pad of the RF element in use in order to effect a coaxial RF interconnection. The conductive contact may take various forms, such as a watch band pin, a Fuzz Button.RTM. or a bellows arrangement. The RF connector may include RF circuitry for interconnection to the RF element and/or may interconnect the RF element to a second RF element.

Abstract: An a.c. cable has at least one cable core (2) with a central carrier body (4), having at least three conductor layers (L.sub.j) of normal conductors or superconductors (3) stranded around it. The conductors preferably have high-T.sub.c superconducting material. The wire angles (.alpha..sub.j) in the individual conductor layers (L.sub.j) are selected so that viewed in the radial direction they gradually increase or decrease from layer to layer. The cable core can advantageously have a concentric arrangement of a forward and a return conductor.

Abstract: A multi-layer thin-film electrode comprises thin conductor films and thin dielectric films each being alternately laminated on a dielectric substrate, in which an electro-magnetic field generated in the dielectric substrate and that generated in each of the thin dielectric films have substantially the same phase at a predetermined frequency.

Abstract: A line radiation preventing element absorbs undesired radio waves superposed upon a wire or a coaxial cable by use of a magnetic substance, instead of reflection of the undesired radio waves and without increasing the cost thereof. The line radiation preventing element for preventing undesired radio waves superposed upon a wire led out of an electronic appliance from being radiated, has a conductive core wire (2) connected to the wire (5) led out of the electronic appliance; a conductive outer pipe (1) arranged concentrically with the conductive core wire (2), one end of the conductive outer pipe being shorted to the conductive core wire by use of at least one of a shorting plate (3) or an electric capacitance (14) and the other end of the conductive outer pipe being opened; and a magnetic substance (7) arranged between the conductive core wire and an inner wall of the conductive outer pipe.

Abstract: A coaxial IF interconnect structure that is compressible in the z-axis and provides its own environmental seal against moisture and coolant. The structure (50) includes three components, a center conductor (60), dielectric spacer structure (70), and outer conductor shield (80), all fabricated of compressible materials. The center conductor is a compressible metal interconnection element formed by die compressing 1 mil diameter fine wire to a desired shape and density. The coaxial dielectric structure supports the compressible center conductor, and is fabricated from a fluorinated elastomer (FM) known as fluorosilicone. The compressible coaxial outer conductor shield functions as an IF gasket in the form of an round flat washer surrounding the dielectric structure and center conductor.

Abstract: A sensor cable formed of a center conductor surrounded by dielectric material and first and second layers. The first layer is formed of a gapped conductive material surrounding the dielectric material. The second layer has predetermined conductivity and at least covers the gaps in the conductive material of the first layer. The predetermined conductivity and thickness of the second layer is such that the skin depth in the second layer at an operating frequency of the cable is much greater than the thickness of the second layer, and inductive coupling into or out of the cable through gaps in the second layer is at least an order of magnitude greater than capacitive coupling into or out of the cable through gaps in the second layer.

Abstract: A variable impedance coaxial transmission line having a center conductor of constant cross-section, an outer conductor surrounding and coaxial with the center conductor and spaced radially therefrom, and a variable dielectric constant material between the center conductor and the outer conductor. The variable dielectric constant material has a plurality of alternating elements of high dielectric material and low dielectric material arranged along the center conductor from a first end to a second end of the center conductor. The invention also includes a reduced size, high-power broadband power/divider incorporating the variable impedance coaxial transmission line.

Abstract: A 6 port TEM cell for measuring garbage EMI/EMS of an electrical and electronic equipment which can form an electromagnetic field of horizontal/vertical polarization using characteristic that internal electric field polarization is changed according to feeder line selection inside a multi-transmission line, and coupling amount among internal conductors is reduced by positioning the spherical internal conductors at corners of external conductors, thereby widening a test area.

Abstract: A coaxial cable comprising a coaxial portion, an integrally formed messenger wire and an integrally formed antenna ground discharge wire is disclosed. The two additional wires are encased in webs formed from the same material used to jacket the coaxial member.

Abstract: An improved electrical signal cable is shown of the type having a plurality of centrally located conductors running along a longitudinal axis of the cable. A shield layer surrounds the plurality of centrally located conductors. A toroid of resistive-inductive material, such as lumped ferrite, is mounted about the plurality of centrally located conductors at one discrete location along the length of the cable by locating the resistive-inductive toroid between the centrally located conductors and the shield layer, common mode emissions are reduced.

Abstract: A shielded flexible cable includes a first shielding grid having conductive elements formed as squares. A second shielding grid is also formed as squares. The two shielding grids are positioned with respect to each other so that the vertices of the squares of the two grids are respectively offset from each other in each of two directions by one-half the diagonal distance between the vertices of the squares. Electrical signal conductors are positioned between the two grids along lines extending between the vertices of the squares to maintain a controlled impedance of the signal lines. A circuit board includes a reference plane configured as a grid having conductive elements formed as squares. Electrical signal conductors are positioned in a plane adjacent said grid.

Abstract: A microwave frequency three-wire transmission line provides the capability of solderless interconnections between stacked microwave hybrid and printed wiring board (PWB) assemblies. Three wire-like compressible conductors are embedded in a dielectric support member. Each compressible conductor is realized by densely packing thin wire into an opening in the supporting dielectric. The dielectric preferably has a metal shielding surrounding the outer periphery to suppress higher order modes. A vertical right angle bend transition uses the transmission line to interconnect between grounded coplanar waveguide (GCPW) transmission lines. This orthogonal transition uses button spring contacts, thus creating a reusable solderless vertical interconnection between the two transmission lines.

Abstract: A transmission line including a dielectric or semi-insulating substrate; a groove in the substrate; a metallization film disposed on the bottom surface of the groove; a dielectric filling the groove and making contact with the metallization film; a wiring conductor film disposed on the dielectric; and a grounding metallization film disposed on the rear surface of the substrate. Excellent confinement of electromagnetic waves is achieved and electromagnetic wave interference between two neighboring lines is extremely small, realizing a high density arrangement of transmission lines and a compact and lightweight microwave/millimeter wave integrated circuit. Higher modes of electromagnetic wave propagation are avoided by controlling the thickness of the dielectric filling the groove while the thickness of the substrate remains arbitrary, thereby improving production yield and reliability.

Abstract: A composite structure including stacked layers of dielectric material hav a center conductor in the form of a cylindrical via which is surrounded by an annular dielectric region and an outer ground plane comprised of contiguous pairs of generally circular ground plane segments where each pair of ground plane segments are separated by a pair of spaces or gaps therebetween and wherein the gaps of adjoining layers are mutually oriented by a predetermined angle of rotation, preferably 90.degree..

Abstract: Signal wiring layers are formed between a power supply layer and a ground layer, which have conductor patterns each constituted by a plurality of parallel strip-shaped conductors. The above layers are isolated from each other by insulating layers. The signal wiring layer has wires which are arranged in parallel with the parallel strip-shaped conductors of the conductor pattern of the power supply layer, and the signal wiring layer has wires which are arranged in parallel with the parallel strip-shaped conductors of the conductor pattern of the ground layer.

Abstract: A multilayer microwave structure for digital, power, RF and other interconnects wherein the metal (3, 7) and insulator (9) structure is built up in additive sequential steps over a base (5). Hermeticity within the structure is provided by forming an oxide layer (65) within the insulator portion of the structure which contacts the metal at all perimeter portions thereof.

Abstract: Continuous, elongated nickel plated graphite fibers are bound with an epoxy and are formed into a structural shape (11). An area (13) of the epoxy is removed by bead blasting to expose a layer of the plated graphite fibers (14), which are aligned in the desired direction of radio frequency current propagation. The bead blasted area (13) is then silver plated to obtain good contact to the plated graphite fibers (14) and resultant high conductivity from the structural shape (11).

Abstract: A microwave frequency transmission line provides the capability of solderless interconnections between stacked microwave hybrid and printed wiring board (PWB) assemblies. A wire-like transmission line is embedded in a dielectric and placed in an open square trough. A compressible center conductor is realized by densely packing thin wire into an opening in the supporting dielectric to form the compressible center conductor. A vertical right angle bend transition uses the transmission line to interconnect between grounded coplanar waveguide (CPWG) transmission lines. This orthogonal transition uses button spring contacts, thus creating a reusable solderless vertical interconnection between the two transmission lines. This transition can operate from DC to greater than 15 GHz with good match and low loss, and allows a transition from a CPWG transmission line on a first substrate to another CPWG transmission line on a second substrate stacked above the first substrate.

Abstract: A low cost shielded transducer cable provides electrical connection between an ultrasound transducer and a display processor. A wound transducer cable is constructed in a first embodiment using two layers of stripline assemblies helically wound in opposite directions around a flexible core. The layers of stripline assemblies are covered with a single metal braid and then coated with insulation. In a second embodiment a stripline transducer cable is formed from a stack of parallel stripline assemblies that may be coextruded with an insulating jacket. In a third embodiment a ribbon transducer cable is formed from a stacked arrangement of parallel ribbon cables and conducting shields that may be extruded in an insulating material.

Abstract: A dielectric rod antenna including a dielectric rod, a ring-shaped conductive film provided on an outer peripheral surface of the dielectric rod, and a waveguide. The conductive film is provided on an outer peripheral surface portion of the dielectric rod which is inclined from a base end portion toward a forward end portion. The conductive film is arranged to intersect the waveguide so as to form a substantially V-shaped cross-sectional area.

Abstract: Disclosed is a high speed coaxial contact and signal transmission element which comprises an inner conductor element 1, an outer conductor element 6 and a dielectric area 4 between the inner conductor element 1 and the outer conductor element 6. The inner conductor element 1 is a continuous element and consists of a core 2 of hardened conductive material exhibiting good elastic properties surrounded by a metal shell 3. A filament 5 of low dielectric constant material is wrapped around the inner conductor element 1 and fixed on the surface of the inner conductor element 1. The outer conductor element 6 consists of a metal shield. These high speed coaxial contact and signal transmission elements are used for the transmission of high speed electrical signals in high density fashion and for contacting and testing electrical devices with minimal dimensions.

Abstract: A TEM mode cell having an internal TEM element and at least one port on the cell, the cell comprising a stepped transmission line transformer coupling the internal TEM element to the port. The stepped transmission line transformer of the TEM mode cell has transfer characteristics selected to give maximum cancellation of VSWR in the cell and thereby enable optimum cell bandwidth. The TEM mode test cell comprises a hollow metallic housing having an enlarged center section with opposite open ends, and a pair of end sections, each end section closing off a respective one of the center section open ends and tapering to a distal end of reduced cross sectional area. A connector is provided at the distal end of each end section, and a stepped septum is mounted within the housing and insulated therefrom, the septum coupled to and extending between the connectors.

Abstract: A strip line component suitable for transporting radio frequency signals from point to point in an electronic assembly, including a first conductive element (13) having a first and a second termination contact (23 and 33), disposed in a planar fashion with a first or length dimension (15) and a second or width dimension (27), a dielectric material (17) suitable as a printed circuit board substrate and having a first planar surface (19), disposed around the first conductive element along the length dimension, where the first termination contact is preferably disposed on the first planar surface, and a second conductive element (21) having a plurality of contacts some of which are preferably on the first planar surface, disposed adjacent to and enclosing the dielectric material along the length dimension and spaced from the first conductive element by a third or height dimension (29) that is perpendicular to the width dimension.

Abstract: To realize an element presenting a constant impedance throughout an extremely wide frequency range and a circuit supplying a high frequency signal having a constant phase throughout the same wide frequency range, a ferrite-loaded line element, a real part of a terminal complex impedance of which is substantially constant, is provided. A partial inclination of an imaginary part of the terminal complex impedance is compensated by providing a pure reactance element, in combination therewith As a result, in an extremely wide frequency range exceeding a natural magnetical resonant frequency, a ferrite-loaded constant impedance element and a constant phase circuit comprising this constant impedance element can be attained.

Abstract: A tetrahedral junction waveguide switch having a first length of hollow rangular waveguide and a second length of hollow rectangular waveguide adjacent each other with a ferrite rod longitudinally disposed therebetween. A magnetic field is created by a superconducting switching coil placed around the junction of the two lengths of waveguide. The normally magnetically biased ferrite rod permits electromagnetic wave energy to be transmitted through the first and second lengths of waveguide. An open circuit control means selectively and controllably interrupts the current flowing around the superconducting switching coil causing the longitudinal magnetic field to be removed from the normally magnetically biased ferrite rod. The waveguide switch is thereby placed in a cut off, nontransmission, or reflective mode preventing transmission of electromagnetic wave energy.

Abstract: An interconnect laminate structure integrates RF and auxiliary (e.g. digital and D.C.) signalling capabilities in a common structure by means of a stacked conductor-plated dielectric configuration that facilitates access to and routing by channelline/waffleline RF transmission links and separate control (e.g. digital, power supply) links, without having to perform laborious manual routing tasks to effect auxiliary connectivity among the components of a network. The interconnect structure includes a first dielectric layer having a channel formed in a first surface thereof, the channel having a conductive surface and configured to accommodate the insertion of a dielectric coated conductor into the channel so as to form an RF transmission line. Second dielectric layers, each of which has a conductive layer formed on a first surface thereof, are mounted together with the first dielectric layer in a laminate assembly.

Abstract: A low attenuation coaxial cable for carrying microwave energy at GigaHertz frequencies includes a center conductor, dielectric surrounding the center conductor and an outer conductor encircling the dielectric. This outer conductor is formed by a plurality of longitudinally extending conductive wire strands positioned adjacent one to another with a slight helical lay along the cable. Internal ruggedization includes a bedding layer of indentable dielectric material encircling the outer conductor with a single-layer ruggedizing winding of strong wire sufficiently tightly wound around the bedding layer for partially indenting this strong wire into the bedding layer. A protective outer jacket of tough plastic material surrounds the ruggedization layer. The helical lay of strong wire in the ruggedization layer is opposite to the slight helical lay of wire strands of the outer conductor.

Abstract: A television receiver powered by an alternating current power source includes an electrically conductive chassis coupled to one side of the AC source, a radio frequency tuner coupled to the chassis, and a coaxial cable having an inner conductor and an outer shielding conductor for supplying filtered radio frequency signals to the tuner. The outer conductor is comprised of an electrically conductive housing circumposing the inner conductor for at least a portion of its longitudinal length, and providing electrical connection and mechanical support for the cable assembly. Filtering of the signal is provided by one or more ferrite beads disposed about the outer conductor, and capristor/capacitor devices.

Abstract: A coaxial cable that includes a first inner conductor, a first dielectric material that encircles the first inner conductor and a first outer conductor that encircles both the first dielectric material and the first inner conductor is improved to comprise a second inner conductor, a second dielectric material, and a second outer conductor. The second inner conductor has a diameter that is larger than the diameter of the first inner conductor and is electrically coupled to the first inner conductor. The geometric shape of the second dielectric material and the second outer conductor, from an axial perspective, is in the range of an ellipse having an eccentricity in a range greater than zero and less than one to an elongated circle.

Abstract: A new interface and a method for making the same, and more particularly, an electrical transmission-line interface and a method for making the same. On a substrate having semiconductors, a driver or receiver circuit is provided to interface with an electrical transmission-line. Integral means for the electrical transmission-line alignment, support and transit through a sealed environment is also provided. A fluid tight seal can also be provided for the various components that are in the interior of the housing. Variable time-delay means is provided for a computer clock system or other microwave applications.

Abstract: A method and system for controlling the transmission of radio frequency energy through an imperforate multi-layer fiber and resin composite structure. Multiple segments of conductive mesh are embedded between layers of fiber and resin in at least partially overlapping positions. Apertures within the conductive mesh are limited to diameters substantially smaller than the wavelengths of the radio frequency energy utilized; however, the apertures are large enough to permit resin to flow into those apertures during the cure process, thereby limiting the possibility of delamination during loading of the resultant composite structure. By utilizing nonconductive materials, such as glass fibers and a resin material having an appropriate dielectric constant, it is possible to create a radio frequency energy guide or capacitive structure which permits the controlled transmission of radio frequency energy through an imperforate composite structure.

Abstract: A dual leaky coaxial cable comprising a pair of parallel elongated conductors, a dielectric surrounding each of the conductors, separate first external conductive shield apparatus surrounding at least the major portion of each of the dielectrics, separate second external shield apparatus surrounding each of the first external shield apparatus, apparatus associated with the shield apparatus for selectively coupling magnetic fields which may surround each of the elongated conductors through the first and second surrounding external shield apparatus, and apparatus for maintaining the individual respective second external shield apparatus separated by a distance which is a fraction of the diameter of either of the second external shield apparatus.

Abstract: The device is of the type comprising a closed test cell the periphery of which is defined by an outer conductor of a TEM waveguide constituted by a tubular casing. An inner conductor of the waveguide extends within the cell. The casing has at least one intermediate portion of uniform rectangular cross-section, in which there is a test region for accommodating an object under test. At least in the intermediate portion, the inner conductor has a substantially arcuate transverse profile, the concave side of which faces the object under test. The inner conductor is preferably constituted by an array of transversely spaced-apart parallel wires arranged so that the array has the said arcuate profile.

Abstract: A low loss coaxial cable has a central supporting rod of plastic, covered in metal and forming the inner conductor or core of the coaxial cable. An intermediate insulation made of a dielectric material surrounds the inner conductor and an outer metal conductor surrounds the intermediate insulation. The central rod is made of polytetrafluoroethylene (PTFE) having a relative density greater than or equal to 1.6. The intermediate insulation has a relative density less than 1.2 and the ratio of the density of the dielectric constituting the intermediate insulation divided by the density of the PTFE constituting the rod lies in the range of 0.15 to 0.75.

Abstract: A polariser particularly suitable for use in receiving satellite television signals includes a ferrite rod located within a waveguide, a yoke co-extensive with the ferrite member and a coil wound around the yoke. The yoke preferably is "U" shaped and includes an arm which projects into the waveguide at the end of the ferrite rod remote from the input of the waveguide.

Abstract: A low-torque microwave cable in which interior metal layers are coated with graphite particles and a process for coating the interior layers with graphite while flexing the cable to reduce stiffness by two-thirds.

Abstract: The present invention relates generally to a new interface and a method for making the same, and more particularly, to an electrical transmission-line interface and a method for making the same. On a substrate having semiconductors, a driver or receiver circuit is provided to interface with an electrical transmission-line. Integral means for the electrical transmission-line alignment, support and transit through a sealed environment is also provided. A fluid tight seal can also be provided for the various components that are in the interior of the housing. Variable time-delay means is provided for a computer clock system or other microwave applications.

Abstract: The present invention comprises a novel semiconductor device which further comprises a nonlinear transmission-line structure. The semiconductor device is that of a very long narrow voltage-dependent capacitor, such as a semiconductor diode or MOS capacitor, where the anode and cathode electrodes comprise the conductors of a transmission line and the depletion region comprises the dielectric of the transmission line. An input signal is applied at one end of the long, narrow structure. Such signal application results in the launch of a traveling wave traveling along the transmission-line structure. At the far end of the transmission-line structure, the signal is coupled out and applied to a load. The temporal and spatial modulation of the depletion capacitance of the semiconductor device as the traveling wave travels along the transmission-line structure results in temporal compression of the input signal.

Abstract: An insulating sleeve for a microwave coupler having two proximately positioned inner conductors, an outer conductor and the sleeve disposed between the conductors and in contact with them. The material from which the sleeve is constructed is electrically insulating and includes a coefficient of linear thermal expansion that is no more than 1.5 times that of the outer conductor in an operating temperature range. The outer conductor may be a copper-based alloy or aluminum and the insulating sleeve material may be, among others, Fluorosint.RTM. 500 or Flurolly H.RTM..

Abstract: A radio signal polarization switching arrangement is responsive to linearly polarized radio signals, such as television signals from a satellite. The switching arrangement which is capable of selecting signals having either one of predetermined states of linear polarization comprises a dielectric support block which supports a ferrite rod axially in a circular waveguide. A metal or metallized layer is deposited on an external surface of the support block and an energizing coil is wound around the layer in axial alignment with the rod. The support block has a stepped configuration at opposite ends in order to compensate for the loading effect of the ferrite rod on the waveguide.

Abstract: An antenna arrangement for receiving television signals from a satellite comprises a parabolic dish which collects the signals and feeds them through a feedhorn, then through a polarization switch and to a low noise block to the receiver. The polarization switch comprises a ferrite rod supported in a dielectric holder within a circular waveguide. The ferrite rod is surrounded by a solenoid coil which is energizable to rotate the plane of polarization of the signals passed along the waveguide, so as to enable the switch to select either horizontally or vertically polarized signals. The current in the coil is switchable between two values, one having a predetermined magnitude in one direction through the coil and the other having the same predetermined magnitude but in the opposite direction through the coil. The current levels are seleced such that the corresponding angular positions for the plane of polarization are +45.degree. relative to the datum position for the polarization plane and -45.degree.

Abstract: An asymmetrically shaped jacketed coaxial electrical cable having a drain wire in which the drain wire is aligned parallel to the asymmetric edge or corner of the cable for fast and accurate termination of the cable.

Abstract: A precision transmission line in the form of a short air line is disclosed. The short air line is approximately one-quarter wavelength at the middle frequency of the measurement frequency range. One embodiment comprises a very short coaxial air line. The inner conductor is threaded onto a mating inner conductor, such as the inner conductor of the network analyzer test port. For reliable interface at the other end of the inner conductor, a precision coaxial connector is preferably provided for connection to a device under test. The outer conductor is then attached coaxially to the inner conductor between the network analyzer test port and the device under test. Another embodiment comprises a waveguide for calibrations at higher measurement frequencies. In the case of the waveguide, locating structure is provided for properly orienting the waveguide with respect to the network analyzer test port and the device under test.

Abstract: A dual frequency feed assembly employing a pair of coaxial circular wave guide cavities, each with respective probe. The higher frequency cavity, e.g. Ku band, is located within the lower frequency, e.g. C band cavity. A common motor is used to drive the two probes which have a common axis A. The lower frequency probe is coupled through the rear wall of the assembly to a rectangular waveguide. The higher frequency probe is also coupled through the rear wall of the assembly but via a coaxial line which is diverted from the axis A to exit beside the lower frequency waveguide. The two rectangular waveguides and the drive motor for the probes are all mounted on the rear of the assembly. In one embodiment of the invention the coaxial line extends from its probe to a housing on the body containing a signal processing circuit board. Connection to that board is made directly eliminating the need for any waveguide transmission line.

Abstract: A shielded cable comprising an assembly of one or more core wires and a shielding member comprising plural element wires around the assembly. The shield member has a single layer structure formed by braiding on the assembly the plural element wires each of which comprises a conductor of high conductivity and spun stainless steel strands woven around the conductor, or a double layer structure comprising two layers, one layer comprising a braid of plural element wires each of which comprises a spun stainless steel strand or spun stainless steel yarns woven around a conductor of high conductivity, and the other layer comprising a braid of plural soft copper wires or copper alloy wires.

Abstract: A multilayer printed circuit board has a plurality of planar layers formed with signal conductor lines and return lines grouped around the conductor lines to form pseudo-coaxial transmission lines. The return lines are grouped symmetrically around each signal line, e.g. two, four, or eight return lines at circumferential positions around each signal line. Ground and power planes may be formed with the multilayer structure for shielding and/or for powering electronic components mounted on the structure. The multilayer techniques can also be used to form a multilayer extender card which minimizes crosstalk and is reduced in cost and assembly time as compared to conventional extender boards.

Abstract: Apparatus for measuring the concentration of one material such as water in another material such as crude or refined oil including a coaxial microwave transmission line formed by a conduit for receiving the material and a center conductor which is sheathed with a dielectric covering which is operable to prevent short circuiting of the transmission path. An oscillator circuit is coupled to the transmission line and is driven by a free-running voltage controlled oscillator and a signal receiver monitors the change in frequency caused by impedance pulling of the oscillator due to the change in the dielectric constant of the mixture. Incident and reflected or transmitted power with respect to the measurement section is measured to determine whether an oil-in-water or water-in-oil emulsion is present to verify the concentration of one fluid in the other for a particular operating frequency.

Abstract: A leaky cable useful antenna or as an intruder detector sensor either buried in a single trench or above ground substantially reducing sensitivity variations due to the environment. Egression of the electric field from the cable is blocked but magnetic fields escape. The velocity of the externally propagating electromagnetic field is slowed and attenuated. In one embodiment, the leaky coaxial cable is comprised of an inner conductor, a dielectric surrounding the inner conductor, a first external shield having low series impedance at VHF frequencies surrounding the dielectric, means for coupling a magnetic field through the first external shield, a second external shield surrounding the first external shield having high series impedance relative to series impedance of the first external shield and means for limiting VHF conduction current between the shields, which effectively causes separation of the internal and external propagation fields of the cables.