Abstract: An electrical connecting element is disclosed comprised of a dielectric substrate having two conductor paths disposed on opposite sides and being substantially aligned with one another. The electrical connecting element employs differential-mode signaling such that the first conductor path carries a signal of opposite polarity to the second conductor path. A virtual ground exists between the differential + and − lines that permits an otherwise “groundless” differential transmission line. The substantial alignment of the first and second conductor paths improves the space constraints, relative to conventional electrical connecting elements. The characteristic impedance of the disclosed differential transmission line depends on the width of the trace lines the thickness of the dielectric substrate.

Abstract: A new method to control differential signal trace impedance allows flexible use of different signal trace width and spacing while maintaining constant differential impedance in printed circuit boards. Differential impedance of a signal pair is determined by the geometry of individual traces and the spacing between traces. The value of the differential impedance is inversely proportional to signal trace width and directly proportional to signal trace spacing. By decreasing or increasing trace width and spacing simultaneously, a constant differential impedance can be achieved.

Abstract: In high-speed semiconductor packaging, differential pair transmission lines 605 are used to receive incoming signals carried using differential signaling. Common mode noise can decrease the frequency at which these signals are clocked. The use of slots 620 formed in the ground (or power plane) 609 of the substrate and lying perpendicularly (and equally spaced) underneath the differential pair 605 improves the common mode rejection of the differential pair 605 by increasing the common mode impedance without affecting the differential mode impedance. The use of slots 620 does not require modifications to the packaging, and only minor modifications to the substrate.

Abstract: A system for ink short protection for signaling to inkjet printheads includes a differential signaling driver having a first and a second terminal, a differential signaling receiver having a first and a second terminal, a first capacitor in series between the first terminals, a second capacitor in series between the second terminals, and circuitry for reducing charge accumulation on the capacitors. A method for ink short protection and a printing mechanism having such an ink short protection system are also provided.

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 circuit in a printed circuit board includes a trace and a ground plane coupled to the trace that includes slots in the vicinity of the trace. The slots are dimensioned and arrayed such that the trace has a controlled impedance. An array of slots progressing in a direction parallel to the trace preferably includes repeating subarrays displaced by a repeat distance in a direction parallel to the trace that is less than a characteristic wavelength of a signal propagated on the trace, coupling distributively with the trace. The slots may be polygonal, arcuate, or a combination of both in shape. The printed circuit board may include a second trace coupled to the first. Further, the printed circuit board may include a second ground plane that includes slots that couple to the trace.

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 system for ink short protection for signaling to inkjet printheads includes a differential signaling driver having a first and a second terminal, a differential signaling receiver having a first and a second terminal, a first capacitor in series between the first terminals, a second capacitor in series between the second terminals, and circuitry for reducing charge accumulation on the capacitors. A method for ink short protection and a printing mechanism having such an ink short protection system are also provided.

Abstract: A vertical transition device for differential stripline paths, connects differential microstrip paths on a horizontal plane with differential triplate paths on another horizontal plane in a multilayered architecture. The differential microstrip paths include a pair of differential microstrip lines. The differential triplate paths include a pair of triplate lines. The differential microstrip lines are connected with the differential triplate lines by via-holes within the transition device, respectively.

Abstract: Impedance values of a common mode choke coil, an impedance element disposed anterior to the common mode choke coil and an impedance element disposed posterior to the common mode choke coil are determined in such a manner that a common mode current flowing into the common mode choke coil does not exceed a value of rated current. Excessive common mode current is prevented from flowing into the common mode choke coil, and saturation and damage of the common mode choke coil is prevented.

Abstract: A vertical transition device for differential stripline paths, connects differential microstrip paths on a horizontal plane with differential triplate paths on another horizontal plane in a multilayered architecture. The differential microstrip paths include a pair of differential microstrip lines. The differential triplate paths include a pair of triplate lines. The differential microstrip lines are connected with the differential triplate lines by via-holes within the transition device, respectively.

Abstract: In an interconnection system including a cable and connectors, compensation is provided for stray reactances found in the connector elements. The connector elements may be RJ-style connector plug and jack pairs, which exhibit characteristic capacitive and inductive properties. The compensation is capacitive and/or inductive elements formed in the cable, components of the connectors, or an external printed wiring board. A double &pgr;-network is the preferred circuit topology for the compensated system.

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: Packaged signal routing circuits (e.g. on printed circuit cards or boards), route pulse signals with very short rise times from a lossy driver to multiple devices. In these routing circuits, a complex network of conductors branches from a common junction adjacent the driver output into multiple conduction paths of unequal length. In accordance with the invention, the internal impedance of the driver is matched to the aggregate characteristic impedance of the branch paths, and a lossless compensating circuit is attached to a shortest branch path. The compensating circuit is designed to transfer signal reflections of predetermined form to the branching junction at the driver via the shortest branch.

Abstract: Packaged signal routing circuits (e.g. on printed circuit cards or boards), route pulse signals with very short rise times from a lossy driver to multiple devices. In these routing circuits, a complex network of conductors branches from a common junction adjacent the driver output into multiple (in the disclosed embodiment, three) conduction paths of unequal length. In accordance with the invention, the internal impedance of the driver is matched to the aggregate charateristic impedance of the branch paths, and a lossless compensating circuit is attached to a shortest branch path. The compensating circuit is designed to transfer signal reflections of predetermined form to the branching junction at the driver via the shortest branch. Without the compensating circuit, reflections presented to the branching junction from the shortest branch are dissimilar to reflections presented to that junction from other branch paths.

Abstract: A signal shielding structure for a cable, such as an audio cable, employs 1) a shielding sheath which is electrically insulated from and encloses the signal-carrying conductors in the cable and 2) one or two discrete inductors electrically coupled between selected discrete points of termination on the shielding sheath and selected ground points to provide a d.c. signal path to ground and to inhibit ground termination of r.f. signals. The shielding sheath floats and is preferably everywhere electrically isolated from direct-wire connection with all grounds and all signal sources except for the connection through the inductor or inductors.

Abstract: A transmission line has a limited cross-section, a transmission line geometry and an improved characteristic impedance tolerance. The transmission line geometry utilizes a unique combination of broadside coupling and coplanar coupling with a reflector plate in order to improve the tolerance of the characteristic impedance. First, a larger coplanar gap is used to reduce the etching error. Second, the inner dielectric thickness sensitivities were also reduced by relying on broadside coupling and coplanar coupling to determine the characteristic impedance of the transmission line. Third, the effect of registration error in the broadside coupling is eliminated by rendering the two signal bearing conductors on the same layer.

Abstract: Disclosed is an adapter which permits transmission of red, green and blue video signals over separate unshielded twisted wire pairs. Crosstalk is minimized by wideband video chokes coupled to each signal input/output.

Abstract: A twisted-pair conductor line structure is formed on a substrate (22) having insulated conductive layers (31, 32). The conductive layers are used to form first, second, third, and fourth conductive planar segments (40, 41, 42, 43). A first conductive link (44) joins the first and second planar conductive segments to provide a first signal path. Similarly, a second conductive link (46) joins the third and fourth planar conductive segments to provide a second signal path. The first and second conductive links are operatively arranged to form a twist (17) in the first and second signal paths, such that the resulting magnetic fields (57, 59) around the twisted conductive segments will be opposite to each other for cancelling each other out, in order to reduce the magnetic field radiation to the surrounding environment.

Abstract: Disclosed is an adapter which permits unbalanced video and audio baseband signals to be transmitted over unshielded twisted pair wiring. The adapter includes low loss transformers which produce a minimum of crosstalk.

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: An audio signal transmission line comprising an additional inductance inserted in series with the line and/or coupled in parallel therewith near the load end of the line for providing a low pass filter which overcomes parasitic and dielectric capacitance of the line so as to reduce audio frequency noise generated in the line by low level and low frequency audio signals. The magnitude of the inductance used may vary widely, e.g. from 20 microhenries to 1 millihenry, depending on the length of the line and the space available.

Abstract: A balanced mode transmission system (20) for use in a local area network includes at least one twisted pair of insulated metallic conductors (27--27) which at its end is connected through a transformer to a transmitting computer and to a receiving computer (48). Each pair of conductors adjacent to the transmitting end and optionally adjacent to the receiving end is provided with a longitudinal choke (56,57). Also, a longitudinally extending metallic wire (60) is included in the system and is connected possibly through a resistor to ground at each end. The combination of the longitudinal choke at least adjacent to the transmitting end and the longitudinally extending metallic wire is superbly effective in suppressing electromagnetic interference notwithstanding the absence of shielding.

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: Input and output equipment are provided for connecting first and second wideband signal transmission mediums through link equivalent to a balanced transmission line. The line can be made up of crosspoint cells includes in a wideband switching matrix, or can be a line distributed to intermediate equipments in a videocommuncation network. The input equipment includes means for separating high and low frequency signals included in the received wideband signals, means for transmitting the high frequency signals in differential mode, and means for transmitting the low frequency signals in High-Input Low-Output (HILO) mode. The output equipment includes means for taking the high and low frequency signals separately and means for summing the high and low frequency signals into wideband signals to be transmitted in the second medium.