Abstract: Methods of active echo reduction on a multi-drop bus utilizing devices of dynamically-variable impedance, wherein non-signaling intermediate devices are placed in a high-impedance state while all remaining devices are matched to the characteristic impedance of the multi-drop bus. Devices of dynamically-variable impedance capable of implementing methods of active echo reduction on a multi-drop bus are included, as well as systems incorporating such devices.

Abstract: This invention relates to an AC power network for collecting the electric powers of distributed power cells. The AC power network of the invention includes a plurality of AC power cells, a plurality of transmission lines, and at least one resistant load. The AC power network has important properties, such as simple structure and easy setup and maintenance. In addition, when there is non-uniform distribution among AC power cells or some AC power cells are broken down, the AC power network possesses equal potential rings or equal potential planes to eliminating non-uniform distribution without decreasing its power efficiency.

Abstract: A multi-phase coupler including a noise reduction circuit which provides two output signals which are separately shifted in phase with respect to an input radio frequency (RF) signal. The input RF signal is capacitively phase-shifted to lead the phase of an input RF signal to provide one output signal and is inductively phase-shifted to lag the phase of an input RF signal to provide a second output signal. The two phase-shifted outputs are impedance matched to the dual input ports of a balanced radiating structure that acts as a point source when the input ports are driven in phase quadrature.

Abstract: A multi-tap RF modulator includes an amplifier for amplifying a telecast RF signal input to an antenna input port; a modulation section for modulating the RF signal output from a VCR, SVR, or game player; and a mixer/splitter having more than one RF output tap and for mixing the first RF signal output from the amplifier and the second RF signal output from the modulation section, the mixed RF signals being distributed into more than one RF signal. The modulator with more than one output tap enables a user to view several TV sets at the same time.

Abstract: A system for the distribution of VTT termination voltage for a GTL bus system includes a plurality of GTL signal lines, a plurality of first termination resistors, and a plurality of second termination resistors. The GTL signal lines have a first end and a second end. The resistors have a signal end and a VTT end. The first end of the signal line is connected to the signal end of the first resistor. The second end of the signal line is connected to the signal end of the first resistor. A plurality of nodes are formed from the VTT ends of the first and second resistors. These nodes may be formed in many different ways, and in many different numbers. The nodes are each driven with a separate VTT supply, and the nodes are interconnected such that a failure in the power supply furnishing power to one node does not affect the other nodes, and does not affect the operation of the system consuming this VTT voltage.

Abstract: An RF power divider is provided for use in a UHF-band high-power amplifier of a radio transmitter. The RF power divider includes: a single input port; first and second output ports; a first microstrip line coupled to the input port; first and second coils coupled in parallel to an output side of the first microstrip line; a second microstrip line coupled between an output side of the first coil and the first output port; a third microstrip line coupled between an output side of the second coil and the second output port; a first capacitor coupled between a ground and a contact point of the first microstrip line and the first and second coils; a resistor coupled between a contact point of the first coil and the second microstrip line, and a contact point of the second coil and the third microstrip line; and a second capacitor coupled in parallel to the resistor. Accordingly, the present invention provides a Wilkinson power divider implemented in a concentrated integer equivalent circuit, in which .lambda.

Abstract: A tool is described for shunting a multi-tap for an RF cable system by connecting a low-pass filter between an unused input port and an unused output port of the multi-tap. The components of the filter are such as not to interfere with the circuits of the multi-tap when both are in the circuit. A light is provided for indicating when the tool is in operative position.

Abstract: A high speed bus circuit system according to the present invention includes a bus having alternately connected resistors and transmission lines, and integrated circuits. Each of the resistors has a predetermined resistance value. The transmission lines are mounted on print circuit boards. The bus is connected in a loop form as a whole. Each of the integrated circuits has a driver and a receiver. The driver and receiver are connected to respective one of the resistors. As a result, DC power dissipation in the terminal resistor of the bus circuit is suppressed. In addition, high speed signal transfer causing less waveform distortion is made possible.

Abstract: An electrical interconnection structure. The electrical interconnection structure includes a mother board substrate having a plurality of layers. At least one layer includes a signal path having a characteristic impedance of Z.sub.O and a conductive ground plane. A signal via passes through each layer of the mother board substrate. The signal via electrically is connected to the signal path. A ground via passes through each layer of the mother board substrate. The ground via is electrically connected to the conductive ground plane. The electrical interconnection structure further includes a plurality of flex circuits. Each flex circuit includes a flex signal path having a characteristic impedance of Z.sub.O and a flex ground plane. Each flex signal path is electrically connected to the signal via and each flex ground plane is electrically connected to the ground via.

Abstract: A line coupler is provided having a bus line piece, at least one transformer, two electrically shielded housings and a coupling site. The transformer is equipped with two primary and two secondary winding terminals. The two primary winding terminals are connected to the pair of coupling elements located at the coupling site. Each coupling element is connected to one of the bus line wires contained in the bus line piece. The secondary winding terminals are connected to branch line wires, which are brought out from the secondary electrical shielded housing. The two electrically shielded housings are electrically connected to each other by two connectors, these connectors also allow the two housings to be releasably connected.

Abstract: The present invention provides for high speed signal buses in printed circuit boards. For high speed operation, each signal line of a bus has substantially the same electrical length as the other signal lines and forms a loop in two halves, each half electrically shielded from the other half. Each signal line has a first and a second terminal, with each terminal connected to a reference bias voltage through a first resistance which matches a loaded characteristic impedance of the signal line. The reference bias voltage is set at a midpoint of signal voltage swings on the signal line. Such high speed buses have particular applications to high speed memory systems with DRAMs.

Abstract: A splitter/combiner module for radio frequency signal circuits includes an electrically conductive housing. Coax connectors are secured to the rear face of the housing. A circuit board is contained within the interior spaced between sidewalls of the housing. A ground side of the circuit board includes a layer of electrically conductive material which is electrically connected to the housing. Components on the circuit board include splitter/combiners for splitting a signal into a plurality of branch signals each having an individual attenuator component.

Abstract: The object of the invention is a radio communication transceiver, in which the low noise pre-amplifier and mixer of the receiver and the power amplifier, directional coupler and the mixer of the transmitter are integrated in connection with the filter section. The active components are integrated with the filter so that the entity forms one component on the circuit board of the telephone.

Abstract: An electronic apparatus capable of transmitting data at two or more different data rates contains transmitter circuitry, a cable connection mechanism, and an isolation transformer having a primary winding and a secondary winding. The transmitter circuitry low-pass filters digital data which the transmitter circuitry transmits to the primary winding at a first data rate. The transmitter circuitry also transmits digital data to the primary winding at a second data rate different from, typically greater than, the first data rate. The cable connection mechanism provides outgoing data from the secondary winding to the communication cable. Importantly, the transmitter circuitry is operable to generate current-sourced data signals at both data rates and then to convert the current-sourced signals into impedance-produced voltage signals that constitute the outgoing data. Current-source amplifier circuitry normally generates the current-sourced signals.

Abstract: A switching coaxial jack includes first and second parallel aligned electrically conductive coaxial center conductors. The center conductors are divided into front and rear portions. The rear portions include movable springs to separate the rear portions from the front portions. A V-shaped switching spring connects the rear portions. Levers push the rear portions out of connection with the switching spring and into connection with the front portions upon insertion of plugs into forward ports of the jack.

Abstract: An active quadrature power splitter having low power consumption is small in size and is inexpensive, for obtaining two output signals of which the phase difference is 90 degrees. Since the active quadrature power splitter operates as a microwave amplifier for obtaining two amplified microwave outputs having an equal magnitude and a phase difference of 90 degrees by using a matching circuit of the amplifier, a power gain can be obtained. Also, since a single FET or HBT is used and two output signals are generated in an output impedance matching circuit, the circuit becomes simplified. Therefore, the circuit can be easily implemented in a monolithic microwave IC and the chip size can be reduced.

Abstract: A communication system having communicating devices coupled to a closed loop bus substantially reduces interconnect distances and corresponding signal propagation delays between the devices. Particular devices possess switchable impedance elements that can be selectively actuated to produce an effective terminating impedance substantially at a midpoint position along the closed loop from the coupling point of a transmission device. In such an arrangement, the produced effective terminating impedance would cause the signal transmitted by the transmission device to propagate to a destination device substantially without signal degradation due to signal reflections.

Abstract: An N-way power combiner is presented herein for combining N RF signals. This combiner includes N input ports each for receiving an RF input signal. N transmission paths respectively extend from the N input ports to a common output port. N reject loads are respectively associated with the N paths, with each reject load having first and second ends with the second ends of the N reject loads being connected together in common. N impedance networks are respectively associated with the N paths. Each of the N impedance networks includes an inductor coil. A common connection means is provided for the inductor coils and the connection means has opposing sides. The N inductor coils are symmetrically arranged relative to the common connection means with some of the coils being located on one side of the common connection means and the other coils being located on the opposite side of the common connection means.

Abstract: In a data communication system, in particular for a motor vehicle, the transmission lines that lead to the individual terminals are interconnected at a passive network in a star configuration and are there provided with frequency-dependent attenuation means, preferably ferrite beads. Good characteristic impedance adaptation is thus obtained for suppressing high-frequency distributing signals, while retaining free choice of the system parameters for the steady data symbolic state. The system may be enlarged by means of additional star networks into a tree or meshed structure.

Abstract: An information system comprises an information network and a station apparatus capable of receiving information from the network and sending a command to the network. An isolator comprises a first diplex filter having an input/output (I/O) port coupled to the network for passing signals with frequencies in first and second non-overlapping ranges. An output port is provided for signals with frequencies in the first range, and an input port is provided for signals with frequencies in the second range. A second diplex filter has an I/O port coupled to the station apparatus for passing signals with frequencies in both the first and second ranges. An input port is provided for signals with frequencies in the first range, and an output port is provided for signals with frequencies in the second range. A first circuit having a bandwidth including the first range provides a first signal path between the output port of the first diplex filter and the input port of the second diplex filter.

Abstract: A termination synthesis technique that automatically derives an optimum termination scheme for interconnects in electronic circuits. The termination synthesis technique uses an adaptive partitioning approach to divide a large circuit into separate clusters that can be independently terminated. The technique can thus automatically derive the optimum termination type and location for large and complex circuits.

Abstract: A method and apparatus is provided allowing a dual-speed network adapter to connect to the same physical connector without the use of mechanical or electro-mechanical switches. On the transmit path, the invention uses a differential amplifier buffer (130) to selectively couple a high speed transmit paths to the network, with the differential amplifier connected to the same output impedance as one of the two driver circuits. On the receive path, the invention allows data to be received in parallel by two receiver circuits, with one circuit isolated from the other with a pair of very high input impedance emitter/followers (40, 50).

Abstract: A high frequency signal dividing and/or combining device includes a circuit formed in a laminated sintered dielectric block, input and output terminals grounded through input and output grounding capacitors respectively, inductors (coils) and a resistor. The coil is formed in a coil section having at least one dielectric layer with a conductive coil pattern. The capacitors are formed in at least three dielectric layers including base, intermediate, and upper dielectric layers. The base dielectric layer includes a grounding electrode pattern providing a common grounding electrode for the input and output grounding capacitors. The intermediate dielectric layer overlaps the base dielectric layer so as to cover the grounding electrode pattern.

Abstract: An adaptive multi-receiver shared antenna matching system and corresponding method includes an antenna (101). A plurality receiver devices (103) are operably coupled to the antenna (101). Degree of coupling between each of the receiver devices (103) and the antenna (101) is dynamically alterable dependent on a degree of coupling model (200) and different signals received by the antenna (101).

Abstract: An impedance matched branch connection for local area networks (LANs). A stub or branch connection increases the number of computers that can connect to a LAN. A star connection is formed when several stub lines are connected at the same point. Stub connections introduce an impedance discontinuity in the line and this discontinuity causes signal reflections which interfere with normal data transmission. The impedance discontinuity is avoided by providing a negative impedance device at the star point which makes the impedance at each transmission line appear as though the stub lines were not added.

Abstract: A jack module including a switching jack subassembly and monitor jack assembly includes a printed circuit board between the subassemblies. The subassemblies and circuit board are commonly housed. The printed circuit board contains monitor circuitry. The monitor circuitry is an inductive monitor with redundant windings.

Abstract: An impedance transforming three-port power divider/combiner includes first, second, and third lumped elements (e.g. 54, 55, and 56). The first lumped element (54) couples the first port (51) and electrical ground. The second lumped element (55) couples the first and second ports (51 and 52), and the third lumped element (56) couples the first and third ports (51 and 53). A resistor (59) is coupled between the second and third ports (52 and 53). Capacitors (57 and 58) couple the second port (52) and the third port (53) to electrical ground. A signal input to the first port (51) results in identical divided output signals at the second and third ports (52 and 53). Signals input to the second and third ports (52 and 53) result in a combined output signal at the first port (51).

Abstract: A miniature coax jack module includes a grounded conductive housing with coax conductors disposed of within the housing. A dielectric insert maintains the conductors in electrically spaced relation to the housing. The housing has internal surfaces surrounding the conductors to provide coax shielding to the conductors.

Abstract: An adapter and control card system for a digital computer is provided for coupling the digital computer to a selectable choice of communications media. The system includes a general-application host card removably insertable into the digital computer, and a communications-medium-specific adapter card removably insertable into the host card, the host card having a cutout conforming to side and end boundaries of said adapter card, the adapter card fitting within the cutout along a substantially common plane in order to minimize surface height of the adapter card and the host card. Mating connectors, particularly between the adapter card and the host card, form transmission lines taking full advantage of ground pins adjacent to signal-carrying differential pairs shielding the signals with a controlled characteristic impedance. In a specific embodiment, the support structure for the connectors also forms the mechanical support for the adapter card and the host card.

Abstract: A passive electric power splitter/combiner comprising a first inductor (117) between an input terminal and a first output terminal, a second inductor (119) between the input terminal and a second output terminal, a first capacitor (111) between the input terminal and ground, a second capacitor (113) between the first output terminal and ground, a third capacitor (115) between the second output terminal and ground, and a resistor (121) between the first output terminal and the second output terminal. Embodiments of the present invention can be fabricated that have little loss other than the intrinsic split loss, exhibit a uniform impedance at all ports, and exhibit electrical isolation between the output ports.

Abstract: A balun circuit comprising a first signal source connected across a first inductive means and connected to the latter a first capacitive means. To that network are connected a second signal source, a second inductive means, and a load to be matched to the signal sources. With the right choice of component values to produce a resonant condition, a balun that interfaces two balanced signal sources to an unbalanced single-ended load results capable of low insertion loss, arbitrary impedance transformation ratio, testability in the form of a 50 ohm port for in-circuit power monitoring and circuit characterization, class E operation, and easy implementation, as only standard L and C components are necessary. The circuit is reversible for connecting a single source to a balanced load.

Abstract: Wiring topology and hierarchy of transmission line impedances for connecting I/O of semiconductor devices together. This arrangement gives smooth signal shapes for signal rise and fall times as fast as one (1) nsec or faster. The design uses a balanced multi-way branched net with increasing impedance until very close to the end, of the net, where it is a balanced multi-way branched net with unterminated ends. Thus, coming out of the signal driver is a single impedance transmission line. This single impedance transmission line (A) then branches into two impedance transmission lines (B), each having an impedance higher than the single line impedance that feeds it. These lines (B) are used to drive electronic modules. After entering the electronic modules through a connector, each of these lines (B) then branch into two transmission lines (C) having a yet higher impedance value. Each of these lines (C) finally ends in a cluster of four transmission lines (D.

Abstract: A disc drive system includes a plurality of subsystems. At least one of the subsystems includes a filter which is completely integrated using a synthetic integrated circuit element.

Abstract: A monostatic frequency modulator continuous wave radar for detecting and determining the distance to near range objects. A temperature compensated one port Z-network is provided to generate a voltage of equal magnitude and opposite sign to that of the voltage reflected from the antenna.

Abstract: A jack module including a switching jack subassembly and monitor jack assembly includes a printed circuit board between the subassemblies. The subassemblies and circuit board are commonly housed. The printed circuit board contains monitor circuitry.

Abstract: A terminator apparatus used with a SCSI bus line controls the voltage level of a notch occurring in data and/or control signals transferred on the bus line. The terminator apparatus includes a termination network, a current switching device, and a programmed monitoring circuit. The termination network generates a first current. The current switching device generates a second current. The monitoring circuit controls a programmed length of time that the second current is generated. The current switching device is responsive to the monitoring circuit for disconnecting the second current when the programmed length of time has been exceeded. The second current serves to raise the voltage level of the notch occurring in the signal lines when they are deasserted so as to prevent erroneous data from being transferred.

Abstract: A data communication field network has a plurality of subscribers connected to it in parallel which have a high input impedance as compared with the characteristic impedance of the network which comprises a main bus into which are inserted first drop and insert devices to constitute secondary buses each comprising two first branches. The connecting device comprises a cable assembly comprising at least two second drop and insert devices inserted into one of the first branches. Each second drop and insert device provides a tertiary bus comprising two second branches. Each tertiary bus is adapted to connect one subscriber and the second branches of the tertiary bus are interconnected at the subscriber connection so as to ensure continuity of the field network and to maintain impedance matching throughout the network.

Abstract: A connector assembly includes first and second conductive probes, first and second conductive shields respectively enveloping the first and second probes in an insulated relationship and a cover insulatingly enveloping the shields. First and second barrels may be disposed within the cover at a first axial end of the cover. Third and fourth barrels may be disposed within the cover, at the opposite axial end of the cover in enveloping relationship to respective ones of the shields. An assembly including an impedance is insulatingly supported by the third and fourth barrels. An actuator assembly insulatingly supported by the first and second barrels has (a) a first operative relationship establishing electrical continuity between the probes and between the shields and (b) a second operative relationship interrupting such continuities and establishing a circuit including an individual one of the probes, the impedance and the corresponding one of the shields.

Abstract: The invention is comprised of printed circuit boards having printed networks for improving electrical isolation at high frequencies. The invention provides more than 25 dB of isolation in the 1 GHz range. The invention is particularly useful for signal splitting applications. Multiple two way splitters, each made in accordance with the present invention, can be combined to form four way splitters, and so on.

Abstract: A phaseshift network (2) exhibits approximately equal impedances to the outputs of an IQ mixer (10), over a range of modulation frequencies (Fm). The phaseshift network furthermore exhibits an approximately equal time delay for the I and Q modulated signals propagating therethrough. The phaseshift network includes a first branch having an input node for receiving a first frequency signal that varies within a range of frequencies about a frequency Fo. The first branch includes a phaseshifter for providing a frequency signal representative of the first input signal that is retarded by a first predetermined number of degrees. The phaseshift network further includes a second branch having an input node for receiving a second frequency signal that varies within a range of frequencies about the frequency Fo. The second branch includes a phaseshifter for providing a frequency signal representative of the second input signal that is advanced by a second predetermined number of degrees.

Abstract: A duplexing filter filters high frequency electromagnetic signals operating in two different frequency bands and uses a common coupling line mounted within an overall housing. Both filters use resonators and may be configured as combine or interdigital type filters. The high frequency filter has at least some of its resonators mounted on a base plate which in turn is positioned at a location along the length of the common coupling line so as to couple the higher frequency filter at its approximate quarter-wave location.

Abstract: A dual output balun distributes substantially all of the available power in a single ended input signal applied thereto (less small parasitic losses) equally to two or more pairs of push-pull output terminals (or vice versa).

Abstract: A bus system wherein the control signal traces on the system board are routed to eliminate noise caused by transmission line reflections. Each control signal trace is routed between the bus controller and the corresponding terminal of the first or last connector of the bus. One side of an isolation resistor whose value preferably matches the lowest impedance of a fully loaded bus is connected to the corresponding terminal of either the first or last connector in the bus connector row through a relatively short trace. The other side of the isolation resistor is connected to a trace which is routed directly to the corresponding terminal of the first of a series of system loads on the system board. The system load traces are then serially continued between each corresponding terminal of each system load until the corresponding terminal of every system load is connected. The serially routed traces are then terminated at the last system load with an RC series network forming an ac termination.

Abstract: A power splitter (10), including a feedback amplifier (16) and matching network (18), is disclosed for splitting the output of a signal source (12) to be applied to a processing system (14). The feedback amplifier includes a gain stage (20) and active load (22). The gain stage includes a field-effect transistor (FET) (Q1) and feedback components (LF and RF) that provide the amplification required to give the power splitter unity gain. An inductive element (LD) gives the amplifier the desired bandwidth and a dual-gate FET (Q2) is employed as the active load to reduce loading of the gain stage. The matching network includes a plurality of stages (e.g., 24), each of which includes a source follower FET (e.g., Q3 ) and a single-gate active load FET (e.g., Q4). The resultant power splitter provides the desired equal power, matched phase outputs with suitable isolation and minimal insertion losses.

Abstract: Input power is applied to an input inductor/capacitor combination. The gates of each of two FETs are connected to the other side of the input inductor. The source of each FET is connected to ground potential. The drain of the first FET is connected to a first output port, and the drain of the second FET is connected to a second output port. A signal input on the drain of one of the FETs is 180.degree. out of phase with the same signal passing through the two FETs to the drain of the other FET. The gate and drain of the first and second FETs have series-connected resistance/inductance feedback networks to give input and output match. A series-connected isolation resistor and inductor are connected between the first and second output ports for feeding signals of reduced amplitude to offset signal feedback through the FETs.

Abstract: An apparatus and method are disclosed for performing impedance transformations on the order of 4:1 to 8:1 or more over extremely broad bandwidths. The transformations are performed in an apparatus having a plurality of n distributed amplifiers having one common synthetic transmission line sharing inductive elements and a second transmission line connected in parallel to the other transmission lines. The transmission lines incorporate active elements preferably in the form of FET cascode pairs. In one embodiment, the second transistor of each cascode pair is replaced with n smaller gate FETs to decrease DC power requirements and provide additional doncution paths for impedance reduction.

Abstract: A method and apparatus for efficiently coupling a transceiver to an AC power line transmission system. The preferred embodiment of the coupling system comprises a line coupling network and first and second filter ports. The first filter port is connected to a resonant circuit having bandpass filtering characteristics adapted to the specific needs of the transmitter portion of the transceiver. The second filter port is isolated from the low impedance of the AC power line and is connected to a high quality factor filter having bandpath filtering characteristics adapted to the specific needs of the receiver portion of the transceiver.

Abstract: A broadband, constant voltage multicoupler including an input port and a plurality of output ports wherein the impedance rises in the same proportion as the power falls in the internal branches so that the voltage is substantially constant therein. The multicoupler comprises a signal splitter transmission line network having an electrical characteristic which maintains the same voltage throughout and a plurality of active devices associated therewith. In particular, the signal splitting network comprises a first transmission line connected at one end to the input and terminating at the opposite end, and a plurality of additional transmission lines having an impedance equal to n times the impedance of the first transmission line where n equals the number of the outputs.

Abstract: A miniature wide-band microwave power divider comprising a common terminal connected to a plurality of parallel signal paths with each signal path comprising a low pass and a high pass filter made up of discrete components. Use of discrete components allows the entire power divider to be incorporated on a single chip. Isolation is achieved between the signal paths by isolation means comprising resistors.

Abstract: A digital to analog converter including an R-2R ladder network receives digitally encoded sample signals in parallel through a set of chains of transistor switches, each chain having equal delay. The ladder network output impedance matches the characteristic impedance of a coaxial cable transmission line that couples the converter output to a utilization circuit. Output resistances of the switches which are connected to ladder network rung circuits are scaled in accordance with a predetermined algorithm to maintain symmetry of parallel connected resistive branches of the latter network seen at each rail terminal of the ladder. Three of the most significant bits of each input binary coded work are decoded to a bar code format before being coupled through the set of switch chains.