Abstract: A system is provided for rapidly prototyping monolithic microwave integrated circuit modules to provide an experimental structure that can be physically made to operate by stereolithographically rendering an SLA part directly from the designer's drawings and by coating the part with a conductive layer, with the smoothness being better than 0.001 inch and with the dimensional accuracy being better than 3 mils for some applications. In one embodiment, the coating for the SLA model is made from either rhodium or gold having a thickness of less than 1/10,000th of an inch, with a nickel barrier being first deposited followed by the gold. The particular SLA plastic is a high temperature plastic to prevent bubbling during the metal deposition step which in one embodiment involves sputtering. The coated model has a microfinish of Ra<0.001 inch, with active devices being electrically attached to the coating through the use of conductive adhesives or eutectic solder.

Abstract: A parallel plate wave-guide structure in a layered flexible/formable medium for transmitting complementary signals, including: at least two parallel signal conductor plates, placed in substantially close proximity, separated by a conductor-to-conductor dielectric material, and having a controlled impedance contained between the at least two parallel complementary signal conductor plates dominated by odd mode propagation of transverse wave components between the at least two parallel complementary signal conductor plates; at least two parallel reference plates forming a parallel plate reference system parallel to and surrounding the at least two parallel complementary signal conductor plates; dielectric materials that are contained between each of the at least two parallel complementary signal conductor plates and a corresponding parallel reference plate; a partial rectangular wave-guide structure comprised of the parallel plate reference system, such that each of the at least two parallel reference plates are

Abstract: An I/O circuit disposed on an integrated circuit substrate and having reduced parasitic capacitance. The I/O circuit includes a signal line segmented into a first signal line segment and a second signal line segment, and an inductive structure disposed between the first and second signal line segments. An on-chip termination element is coupled to the first signal line segment, and an electrostatic discharge (ESD) element is coupled to the second signal line segment.

Abstract: A technique for facilitating signal transmission at high signal frequencies in a multi-layer substrate is disclosed. In one embodiment a multi-layer substrate comprises a conductor or pair of conductors, a first dielectric layer on a first side of the conductor or pair of conductors and a second dielectric layer on a second side of the conductor or pair of conductors. An air channel is provided in the first dielectric layer, the air channel formed to be substantially coextensive with the conductor or pair of conductors. A conductive shield surrounds the conductor or pair of conductors, the first dielectric layer, and the second dielectric layer in order to eliminate crosstalk. The conductor or pair of conductors may have discrete spaced edges and the width of the conductor or pair of conductors may be increased in order to adjust the impedance because of the low dielectric constant of air. Furthermore, additional air channels and a supporting layer may be included in the structure.

Abstract: A technique for facilitating signal transmission at high signal frequencies in a multi-layer substrate is disclosed. In one embodiment a multi-layer substrate comprises a conductor or pair of conductors, a first dielectric layer on a first side of the conductor or pair of conductors and a second dielectric layer on a second side of the conductor or pair of conductors. An air channel is provided in the first dielectric layer, the air channel formed to be substantially coextensive with the conductor or pair of conductors. A conductive shield surrounds the conductor or pair of conductors, the first dielectric layer, and the second dielectric layer in order to eliminate crosstalk. The conductor or pair of conductors may have discrete spaced edges and the width of the conductor or pair of conductors may be increased in order to adjust the impedance because of the low dielectric constant of air. Furthermore, additional air channels and a supporting layer may be included in the structure.

Abstract: A wired transmission path includes first and second differential transmission paths. The first differential transmission path is composed of two strip lines, and the second differential transmission path is composed of two strip lines. Each of the strip lines of the first differential transmission path is disposed at an equal distance from the strip lines of the second differential transmission path. Thus, there is provided a wired transmission path including a plurality of differential transmission paths in such a manner so as to cancel crosstalk.

Abstract: A differential signal transmission cable structure for transmitting differential signals having GHz frequency band in the present invention is provided with a differential signal transmission pair cable 30 connecting a driver circuit 23a and a receiver circuit 23b, for transmitting differential signals having GHz frequency band, and a power supply ground transmission pair cable 31 connecting ground and a first power supply 26a connected to the driver circuit and ground and a second power supply 26b connected to the receiver circuit. Further characteristic impedance of the differential signal transmission pair cable is matched to that of the driver circuit and the receiver circuit, thereby enabling TEM waves of differential signals having GHz frequency band transmission mode to be maintained when the differential signals are transmitted.

Abstract: A high speed switching apparatus comprises first and second parallel balanced lines each directed from an input line end to an output line end and adapted to receive equal and opposite currents to provide balanced operation. Third and fourth parallel balanced lines are spaced apart one from the other and each directed from an input line end to an output line end and adapted to receive equal and opposite currents to provide balanced operation. A first switch is coupled between the output end of the first line and the input end of the third line, and operative in a first high impedance off state and a second low impedance on state. A second switch is coupled between the output end of the second line and the input end of the fourth line, and operative in a first high impedance off state and a second low impedance on state.

Abstract: A high frequency transmission cable includes one or more propagation channel sets, an inner covering wrapping the propagation channel sets and providing an effect of shield, drain wires and a jacket. Two conductors in each of the propagation channels are joined to each other tightly as a single piece to perform communication of electrical appliances in a way of the conductor pair juxtaposing and being flush with each other surely for avoiding signals transmitted in the conductors becoming not synchronous due to the conductors being in inconsistent length resulting from the cable being bent so as to enhance the frequency width of the transmission cable.

Abstract: A printed circuit board includes two differential signal traces, a layer of core material, a layer of filler material, and a ground plane. The filler material is replaced by an air core under the differential signal traces.

Abstract: An engineered transmission line for transmitting high-frequency data signal s between two points of connection includes a dielectric body and a plurality of conductive elements disposed thereon, with the plurality of conductive elements being arranged in pairs for differential signal transmission. In one embodiment, the dielectric body is solid and has its conductive elements supported on its exterior surface. In another embodiment, the dielectric body is extruded and has grooves or raised lands formed therein. The grooves or lands support conductive elements formed thereon by a suitable plating process. A ground plane may be provided as a base layer of the dielectric body.

Abstract: A wired transmission path 1 includes first and second differential transmission paths 12 and 13. The first differential transmission path 12 is composed of two strip lines 121 and 122, and the second differential transmission path 13 is composed of two strip lines 131 and 132. Each of the strip lines 121 and 122 is disposed at an equal distance from the strip lines 131 and 132. Thus, there is provided a wired transmission path including a plurality of differential transmission paths in such a manner as to cancel crosstalk.

Abstract: An electronic apparatus with a high inductive reactance for differential signals per unit area and a small inductive reactance for common-mode signals relative to its inductive reactance for differential signals with predictable and scalable characteristics. This may be achieved by configuring transmission line pairs such that currents associated with the differential component of a source signal in the first and second transmission lines are aligned and currents associated with the common mode component of a source signal in the first and second transmission lines are counter-aligned. Advantageously, the current invention may be implemented using currently available technology and integrated into a variety of different devices such as broad-band and narrow-band amplifiers, high-speed logic gates, mixers, oscillators, wireless local area networks, global positioning systems and modern communication systems.

Abstract: A semiconductor chip is provided with a dielectric element having conductive features interconnecting electronic elements within the chip with one another. The conductive features replace internal conductors, and can provide enhanced signal propagation between elements of the chip. The conductive features on the dielectric element are connected to contacts on the chip by deformable conductive elements such as flexible leads so that the dielectric element remains movable with respect to the chip. The dielectric element may have a coefficient of expansion different from that of the chip itself.

Abstract: An engineered transmission line for transmitting high-frequency data signal s between two points of connection includes a dielectric body and a plurality of conductive elements disposed thereon, with the plurality of conductive elements being arranged in pairs for differential signal transmission. In one embodiment, the dielectric body is solid and has its conductive elements supported on its exterior surface. In another embodiment, the dielectric body is extruded and has grooves or raised lands formed therein. The grooves or lands support conductive elements formed thereon by a suitable plating process. A ground plane may be provided as a base layer of the dielectric body. Enlarged conductive surfaces may also be provided on the body which have a greater surface area than those intended for use with the signal channels. The enlarged surfaces are utilized to carry power.

Abstract: A technique for improving signal reach and signal integrity when using high bit rates or high signal frequencies is provided. A multi-layer substrate comprises a conductor having a continuous main path and discrete spaced edges protruding from opposing edges of the continuous main path. A first spacer layer is disposed on a first side of the conductor, the first a spacer layer having an air channel substantially coextensive with the continuous main path and a solid portion overlapping with the discrete spaced edges. A second spacer layer is disposed on a second side of the conductor, the second spacer layer having an air channel substantially coextensive with the continuous main path of the conductor and a solid portion overlapping with the discrete spaced edges.

Abstract: A technique for facilitating signal transmission at high signal frequencies in a multi-layer substrate is disclosed. In one embodiment a multi-layer substrate comprises a conductor or pair of conductors, a first dielectric layer on a first side of the conductor or pair of conductors and a second dielectric layer on a second side of the conductor or pair of conductors. An air channel is provided in the first dielectric layer, the air channel formed to be substantially coextensive with the conductor or pair of conductors. A conductive shield surrounds the conductor or pair of conductors, the first dielectric layer, and the second dielectric layer in order to eliminate crosstalk. The conductor or pair of conductors may have discrete spaced edges and the width of the conductor or pair of conductors may be increased in order to adjust the impedance because of the low dielectric constant of air. Furthermore, additional air channels and a supporting layer may be included in the structure.

Abstract: A flexible circuit board with specific shielding planes is used for low voltage differential transmission mode circuits. Both the impedance and the transmission time for the transmission line in the circuit board are controlled by shielding planes with varied void opening patterns. Capacitance and slow wave effects related to the combination of void opening patterns and the location configuration related to locations of void opening patterns are used to improve the impedance and transmission timing for the transmission line in the circuit board.

Abstract: In one aspect, the invention relates to a waveguide structure for differential transmission lines. The waveguide structure includes a first ground structure, a first signal line, a second ground structure, a second signal line, a third ground structure. The first signal line is typically positioned adjacent and substantially parallel to the first ground structure. The second ground structure has a first separation distance from the first ground structure and is typically positioned adjacent and substantially parallel to the first signal line. The first signal line is typically positioned between both the first and second ground structures. The second signal line typically has a second separation distance from the first signal line and is positioned adjacent and substantially parallel to the second ground structure. The second ground structure is typically positioned between both the first and second signal lines.

Abstract: A common mode termination includes a shielded connector, a receive section and a transmit section, each section comprising an isolation transformer, a common mode transformer, a reference autotransformer, and an AC shield return. Each transmit section reference autotransformer and receive section reference autotransformer has a center tap for the application of a bias voltage and a bias voltage return. The bias voltage is fed through a common mode transformer, and the resultant common mode termination reduces the conduction of EMI from the serdes coupled to the common mode termination to cables connected to the connector. This common mode termination also provides a reference termination for the copper twisted pair cable and reduces resonances on the cable. Finally, this termination also provides filtering on the DC power source wires and improves noise immunity from transients coupled onto the twisted pair cable into the system.

Abstract: An interface method and system for interfacing a DC unbalanced databus with a DC balanced databus suited for use in an aircraft. The system includes a DC unbalanced databus and a controller coupled to the DC unbalanced databus. An alternating DC unbalanced voltage differential signal is transmittable from the controller to a first transformer which is coupled to the controller. The alternating DC unbalanced voltage differential signal may be stepped-up and DC balanced by the first transformer to create a DC balanced voltage differential signal. A transmitter is coupled to the first transformer, where the transmitter comprises a high power differential voltage driver. The DC balanced voltage differential signal may be stepped up by the transmitter to a high drive current signal. A second transformer is coupled to the transmitter, and at least one DC balanced databus is coupled to the second transformer. A waveform shaping network may be coupled between the second transformer and DC balanced databus.

Abstract: This invention is a broadband matrix switch system and method of operation. The broadband matrix switch has N number of broadband inputs, each of the broadband inputs having one or more broadband signals. The matrix switch has M number of broadband outputs. There are N number of splitters. Each of the splitters has a splitter input connected to one of the broadband inputs. Each of the splitters has M number of splitter outputs that produce the splitter output signal. There are N times M number of node switches. Each node switch is uniquely connected to one of the splitter outputs. The node switches have a control input that allows the node switch to pass the respective splitter output signal upon receiving a close command at the control input and to terminate the respective splitter output signal with an input impedance upon receiving an open command at the control input. There are M number of combiners. Each combiner has a combiner output connected to one of the broadband outputs.

Abstract: Method and apparatus for enabling the transmission of high bandwidth analog and digital data over cable lengths of more than 1000 feet through low cost semishielded or unshielded four wire cable are disclosed. Three balanced mode signals are transmitted using four conductors. In this configuration, the components A+ and A- of a first balanced mode signal A are respectively carried on a first pair of conductors, the components B+ and B- of a second balanced mode signal B are respectively carried on a second pair of conductors, and the components C+ and C- of a third balanced mode signal C are respectively carried on a pair of conductors synthesized through the commonality of the first and second conductor pairs, respectively. Using this technique, a new additional virtual ground plane is created wherein signal energy can be transmitted without interfering or combining with the other signals being transmitted on the remaining conductor pairs.

Abstract: In an apparatus for EMC testing of electrical devices, conductors are arranged at opposite sides of a chamber of conductive material at a spacing from and parallel to the chamber walls. These conductors form a symmetrical double line and are fed out of phase at one end by a radio frequency source. They are electrically connected to the chamber walls at the other end via terminating impedances.

Abstract: A signal cable is provided with a first signal line and second signal line which are respectively connected between a first signal device and a second signal device and are constructed so as to transmit appointed signals, wherein the second signal line is a constant potential line and connects the first shielding line to the second signal line at the same potential at the first signal device side and simultaneously connects the second shielding line to the second signal line at the same potential at the second signal device side.

Abstract: A thick film balanced line multilayered structure having a substrate base of nominal 0.025 or 0.030 inch thick ceramic material, a first metal layer deposited on the substrate base, a nominal 0.003 inch thick dielectric layer deposited over and around the first metal layer, and a second metal layer deposited on top of the dielectric layer in alignment with and parallel to, the first metal layer. The structure defines a standard circuit cell suitable for use in microwave splitters. The impedance of the cell is controlled by the width of the metal layers, and ranges from 5 ohms to 125 ohms, and the frequency of the cell is controlled by the length of the metal layers.

Abstract: A transformation network is provided capable of interfacing between an unbalanced port (110) and a plurality of differently phased balanced ports (120, 130). A balun (165) has a choke (140) and connects the unbalanced port (110) to a balanced pair of nodes. An additional node (145) is provided on the balun. First and second unbalanced phase shift transmission lines (150, 155) have a common ground conductor connected to the additional node (145) of the balun (165). A phase-shifted balanced port (130) is thus provided by center conductors of these first and second unbalanced phase shift transmission lines (150, 155) when the other ends of these transmission lines are coupled to the balanced nodes of the balun (165) and the common ground conductor of these transmission lines is connected to the additional node (145) of the balun.

Abstract: A thick film balanced line multilayered structure having a substrate base of nominal 0.025 or 0.030 inch thick ceramic material, a first metal layer deposited on the substrate base, a nominal 0.003 inch thick dielectric layer deposited over and around the first metal layer, and a second metal layer deposited on top of the dielectric layer in alignment with, and parallel to, the first metal layer. The structure defines a standard circuit cell suitable for use as a balun, a capacitor or an autotransformer, for use in microwave mixers, power splitters, filters, resonators and other microwave devices. The impedance of the cell is controlled by the width of the metal layers, and ranges from 5 ohms to 125 ohms, and the frequency of the cell is controlled by the length of the metal layers.

Abstract: A connector for communications systems has four input terminals and four output terminals, each arranged in an ordered array. A circuit electrically couples each input terminal to the respective output terminal and cancels crosstalk induced across the adjacent connector terminals. The circuit includes four conductive paths between the respective pairs of terminals. The first and third paths are in relatively close proximity and are substantially spaced from the second and fourth paths. The second and fourth paths are in relatively close proximity.

Abstract: A connector for communications systems has four input terminals and four output terminals, each arranged in an ordered array. A circuit electrically couples each input terminal to the respective output terminal and cancels crosstalk induced across the adjacent connector terminals. The circuit includes four conductive paths between the respective pairs of terminals. Each conductive path includes a plurality of conductive strips arranged in a zig-zag pattern with alternating strips mounted on opposite sides of the substrate and connected end-to-end by conductive devices passing through the substrate. The first and third paths are in relatively close proximity with conductive strips of the first path crossing conductive strips of the third path on opposite sides of the substrate to simulate a twisted wiring pair.

Abstract: To reduce crosstalk in reentrant off-chip RF selectivity, differential circuits (402, 415), transmission lines (423, 424), and off-chip filters (422) are used in a structure that balances the parasitic capacitances associated with all of the differential elements. The structure includes a substrate (409) with a differential generating circuit (402) and a receiving circuit (415). Two differential transmission lines (423, 424), each with constant characteristic impedance, and each with balanced capacitance to ground, both being closely spaced for some distance, couple the circuits (402, 415) to closely spaced terminating pads (403). A ground plane (412) is shared under both transmission lines (423, 424). A second substrate (408) having a reentrant RF path (406) with the first substrate (409) contains an RF function such as a filter or a delay line.

Abstract: By on-chip modification of a conventional balanced driver to yield special voltage levels, the power dissipation of a balanced, terminated transmission line circuit can be reduced by 50% or more relative to a conventional balanced driver or 25% or more relative to a conventional unbalanced driver. This reduction in power dissipation not only applies to point-to-point interconnections but also applies to bused interconnections. The low power balanced driver circuit can be implemented using ECL, BiCMOS, GaAs and CMOS technologies and no modifications are needed to the associated differential line receiver. Thus, the significant benefits of balanced interconnections, namely reduced crosstalk, increased noise immunity, and elimination of ground noise can be realized with a significant reduction in power dissipation.

Abstract: An electrical system wherein the electrical conductive traces on the circuit boards are routed to achieve a balanced net to reduce noise caused by transmission line reflections. A trace is routed from the source terminal of the net to a balanced junction wherein if there are an odd number of load terminals, or loads, the balanced junction is located at one of the loads. The remaining loads are grouped into branches wherein each branch includes an equal number of loads. A trace is routed between each of the loads of each branch to serially connect the loads of each branch together, or, a trace is routed from a center one of the branch loads to each of the remaining branch loads, forming subbranches. In an alternate embodiment, a balanced subbranch is developed. The balanced load is connected to a pseudo-balanced load, which further receives an equal number of branches. The pseudo-balanced load is then connected to another pseudo-balanced load, which may also receive an equal number of branches.

Abstract: A broadband, inductively coupled, duplex, radio frequency (RF) transmission system for communcating between a central unit (10) and a plurality of remote units (31) is disclosed. The central unit (10) includes an RF signal source (11) and an RF receiver (21) connected to one end of a balanced transmission line (25) via a signal splitter (15) and a transmission line impedance matching network (27). Each remote unit (31) includes a receiving section (33) and a transmitting section (35) separate from one another. Each receiving section (33) and each transmitting section (35) includes U-shaped couplers (37,43) positioned so as to overlie the balanced transmission line (25). The U-shaped couplers (37,43) are oriented such that the cross-members of the U-shaped couplers (37,43) lie orthogonal to the balanced transmission line (25) and the legs of the U-shaped couplers (37,43) lie parallel to the balanced transmission line (25).

Abstract: An in-phase hybrid and a balun in a single stage built with inexpensive coaxial cable which splits or combines RF power and simultaneously performs a balanced-to-unbalanced impedance transformation.

Abstract: A circuit assembly including a plurality of integrated circuit chips wherein electrical interconnections between chips at a relatively large distance from each other are accomplished by a conductor bus comprising a first section including conductors running adjacent and parallel to each other for a distance substantially equal to an integral number of half wavelengths of the base frequency of signals of the circuit and second sections including conductors which sharply diverge toward associated integrated circuit chips for electrical connection therewith.

Abstract: An electrical transmission unit line is provided comprising a porous dielectric layer having positioned on one side thereof a pair of narrow, parallel elongated electrical conductors and on the other side thereof, opposite the pair of conductors and extending transversely across both wires of the pair and parallel thereto, a wide ground conductor. An electrical transmission line having a plurality of such unit lines is also provided. The porous dielectric is preferably porous, expanded polytetrafluoroethylene. The transmission lines are covered with an electrically insulating material, preferably a nonporous plastic.

Abstract: A non-contacting type of high frequency signal coupling arrangement for coupling RF signals to a television receiver at one or more workstations for alignment or test includes a first transmission line mounted a the workstation and coupled to the RF signal source and a second transmission line mounted on the pallate for moving the television receiver from one workstation to another and coupled to the antenna input of the television receiver. At a workstation, the two transmission lines are brought into overlying relationship so that the RF signals are capacitively coupled from the first transmission line to the second.

Abstract: A balanced-line transmission cable is disclosed for use in a communications system of the type having a differential driver which transmits a differential output in the form of two output voltage signals which are transmitted to two corresponding inputs of a differential receiver which produces an output proportional to the difference between the two input voltage signals. A woven balanced line transmission cable includes a plurality of balanced-line signal conductor pairs each pair consisting of first and second signal transmission wires laterally spaced closely adjacent one another and lying generally parallel with one another in the cable. The first and second signal transmission wires transmit one each of the two voltages for input into the differential receiver. A plurality of fiber warp and weft yarns are interwoven in the cable with the signal conductor wire pairs fixing the lateral spacing and parallel alignment of the first and second signal transmission wires.

Abstract: This invention relates to a transmission system for transmitting electrical signals whereby the conductor path consists of several sections of a cable which contain a number of twin conductors and wherein inductances are inserted at fairly great distances in the form of bi-filar chokes at least for the double conductors so as to cause unbalanced to ground currents to be essentially damped.