Patent•
Improving signal integrity in differential signal systems
29 Sep 2001-
TL;DR: In this paper, the authors proposed overterminating the differential mode impedance of a differential transmission line, such as an INFINIBAND™ cable, at the receiving end, to improve the differential signal integrity for typical variations in termination network impedance component.
Abstract: Over-terminating the differential mode impedance of a differential transmission line, such as an INFINIBAND™ cable, at the receiving end, improves the differential signal integrity for typical variations in termination network impedance component (e.g., resistor) and transmission line characteristics. Eye opening of the differential signal can be made larger with reduced attenuation but increased jitter compared to under-terminating the differential mode impedance. Because the differential signal quality (larger eye opening) is improved, data can be transmitted over a longer transmission line with the same transmitter and receiver.
Citations
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Patent•
AT&T1
TL;DR: In this paper, the authors describe a system that receives, by a feed point of a dielectric antenna, electromagnetic waves from a core coupled to the feed point without an electrical return path, and radiates a wireless signal responsive to the electromagnetic waves being received at the aperture.
Abstract: Aspects of the subject disclosure may include, for example, receiving, by a feed point of a dielectric antenna, electromagnetic waves from a dielectric core coupled to the feed point without an electrical return path, where at least a portion of the dielectric antenna comprises a conductive surface, directing, by the feed point, the electromagnetic waves to a proximal portion of the dielectric antenna, and radiating, via an aperture of the dielectric antenna, a wireless signal responsive to the electromagnetic waves being received at the aperture. Other embodiments are disclosed.
330 citations
Patent•
AT&T1
TL;DR: In this paper, a distributed antenna and backhaul system provide network connectivity for a small cell deployment using high-bandwidth, millimeter-wave communications and existing power line infrastructure, rather than building new structures, and installing additional fiber and cable.
Abstract: A distributed antenna and backhaul system provide network connectivity for a small cell deployment. Rather than building new structures, and installing additional fiber and cable, embodiments described herein disclose using high-bandwidth, millimeter-wave communications and existing power line infrastructure. Above ground backhaul connections via power lines and line-of-sight millimeter-wave band signals as well as underground backhaul connections via buried electrical conduits can provide connectivity to the distributed base stations. An overhead millimeter-wave system can also be used to provide backhaul connectivity. Modules can be placed onto existing infrastructure, such as streetlights and utility poles, and the modules can contain base stations and antennas to transmit the millimeter-waves to and from other modules.
298 citations
Patent•
AT&T1
TL;DR: In this article, a distributed antenna system is provided that frequency shifts the output of one or more microcells to a 60 GHz or higher frequency range for transmission to a set of distributed antennas.
Abstract: A distributed antenna system is provided that frequency shifts the output of one or more microcells to a 60 GHz or higher frequency range for transmission to a set of distributed antennas. The cellular band outputs of these microcell base station devices are used to modulate a 60 GHz (or higher) carrier wave, yielding a group of subcarriers on the 60 GHz carrier wave. This group will then be transmitted in the air via analog microwave RF unit, after which it can be repeated or radiated to the surrounding area. The repeaters amplify the signal and resend it on the air again toward the next repeater. In places where a microcell is required, the 60 GHz signal is shifted in frequency back to its original frequency (e.g., the 1.9 GHz cellular band) and radiated locally to nearby mobile devices.
296 citations
Patent•
AT&T1
TL;DR: In this article, the authors describe a device that facilitates transmitting electromagnetic waves along a surface of a wire that facilitates delivery of electric energy to devices, and sensing a condition that is adverse to the electromagnetic waves propagating along the surface of the wire.
Abstract: Aspects of the subject disclosure may include, for example, a device that facilitates transmitting electromagnetic waves along a surface of a wire that facilitates delivery of electric energy to devices, and sensing a condition that is adverse to the electromagnetic waves propagating along the surface of the wire. Other embodiments are disclosed.
288 citations
Patent•
AT&T1
TL;DR: In this article, a system for detecting a fault in a first wire of a power grid that affects a transmission or reception of electromagnetic waves that transport data and that propagate along a surface of the first wire is described.
Abstract: Aspects of the subject disclosure may include, for example, a system for detecting a fault in a first wire of a power grid that affects a transmission or reception of electromagnetic waves that transport data and that propagate along a surface of the first wire, selecting a backup communication medium from one or more backup communication mediums according to one or more selection criteria, and redirecting the data to the backup communication medium to circumvent the fault. Other embodiments are disclosed.
286 citations
References
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Book•
25 Aug 2000
TL;DR: This book provides a much-needed, practical guide to the state of the art of modern digital system design, combining easily accessible explanations with immensely useful problem-solving strategies.
Abstract: From the Publisher:
An understanding of high-speed interconnect phenomena is essential for digital designers who must deal with the challenges posed by the ever-increasing operating speeds of today's microprocessors This book provides a much-needed, practical guide to the state of the art of modern digital system design, combining easily accessible explanations with immensely useful problem-solving strategies Written by three leading Intel engineers, High-Speed Digital System Design clarifies difficult and often neglected topics involving the effects of high frequencies on digital buses and presents a variety of proven techniques and application examples Extensive appendices, formulas, modeling techniques as well as hundreds of figures are also provided
427 citations
Patent•
10 Sep 1993TL;DR: In this article, a system of terminating a differential transmission line is described, where the differential transmitter and differential receiver are supplied by different power sources, and the termination circuit comprises an unbalanced voltage divider pair, a connection to the receiver's voltage source, an adjustable threshold voltage, and circuitry to reduce power consumption.
Abstract: A system of terminating a differential transmission line is described, where the differential transmitter and differential receiver are supplied by different power sources. The termination circuit comprises an unbalanced voltage divider pair, a connection to the receiver's voltage source, an adjustable threshold voltage, and circuitry to reduce power consumption. An unbalanced voltage divider pair provides matched termination impedances, and prevents undesired receiver output upon loss of transmitter signals. The voltage supplying the unbalanced voltage divider pair provides a voltage differential at the receiver inputs upon loss of the transmitter power source. An adjustable threshold voltage provides the minimum receiver input threshold voltage on which the transmitter signals can be superimposed. Power consumption is reduced through the use of a current limiter, which is coupled with a high pass filter to maintain the characteristic impedance of the transmission line during high frequency transmission. SEP
60 citations
Patent•
20 Jul 1994
TL;DR: In this article, a switchable impedance matching termination apparatus is provided including a terminating resistor network for terminating at least one pair of a plurality of differential signal line pairs, and an enabling signal input is also provided.
Abstract: A method and apparatus electrically disconnects termination on a differential transmission bus. A switchable impedance matching termination apparatus is provided including a terminating resistor network for terminating at least one pair of a plurality of differential signal line pairs. An enabling signal input is also provided. Further, the invention has a first signal network interconnected between the enabling signal input and the terminating resistor network. Also provided is a second signal network interconnected between the enabling signal input and the terminating network wherein the first and second signal networks are responsive to the signal. The response is designed to terminate the at least one pair of the plurality of differential signal line pairs. A method is also provided for disconnecting terminating resistors on a device having a differential transmission line.
37 citations
Patent•
23 Aug 1994TL;DR: In this paper, a wiring hub for interconnecting a plurality of network components to form a local area network, the wiring hub including a data signal bus and a programmable switching mechanism is described.
Abstract: A wiring hub for interconnecting a plurality of network components to form a local area network, the wiring hub including a data signal bus and a programmable switching mechanism connected to the data signal bus. The switching mechanism includes a plurality of ports each of which can be electrically coupled to a different one of the plurality of network components so as to pass communications signals to and receive communications signals from the network component to which it is coupled. The programmable switching mechanism interconnects a selectable set of the plurality of ports together through the data signal bus and in any user selectable ordered sequence.
23 citations
Patent•
21 Jun 1996TL;DR: In this paper, a single-ended signal line interface circuit is coupled between the peripheral bus signal line and the peripheral controller, and may be selectively enabled in response to a control signal.
Abstract: A peripheral device interface is coupled between a computer system bus and a peripheral bus. The peripheral device bus includes a signal line which can be configured in either a single-ended or a differential configuration. A peripheral controller is coupled to the computer system bus. A single-ended signal line interface circuit is coupled between the peripheral bus signal line and the peripheral controller, and may be selectively enabled in response to a control signal. A differential signal line interface circuit is also coupled between the peripheral bus signal line and the peripheral controller and also may be selectively enabled in response to a control signal. The peripheral controller generates the control signals for the single-ended signal line interface circuit and the differential signal line interface circuit. Those control signals enable the single-ended signal line interface circuit when the peripheral bus signal line is a single-ended signal line and enable the differential signal line interface circuit when the peripheral bus signal line is a differential signal line.
23 citations