The present invention provides a robot for use inside an open abdominal cavity during minimally-invasive surgery. The robot may include various sensors, imaging devices or manipulators.

Robot for surgical applications

Signal integrity has become the key issue in most high-performance digital designs. Now, from the foremost experts in the field, this book leverages theory and techniques from non-related fields such as applied physics, communications, and microwave engineering and applies them to the field of high-speed digital design. This approach creates an optimal combination of theory and practice that is meaningful to practicing engineers and graduate students alike.

Advanced Signal Integrity for High-Speed Digital Designs

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.

Method and apparatus for coupling an antenna to a device

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.

Backhaul link for distributed antenna system

Aspects of the subject disclosure may include, for example, a transmission device that includes a transmitter that generates a first electromagnetic wave to convey data. A coupler couples the first electromagnetic wave to a single wire transmission medium having an outer surface, to forming a second electromagnetic wave that is guided to propagate along the outer surface of the single wire transmission medium via at least one guided wave mode that includes an asymmetric or non-fundamental mode having a lower cutoff frequency. A carrier frequency of the second electromagnetic wave is selected to be within a limited range of the lower cutoff frequency, so that a majority of the electric field is concentrated within a distance from the outer surface that is less than half the largest cross sectional dimension of the single wire transmission medium, and/or to reduce propagation loss. Other embodiments are disclosed.

Guided-wave transmission device with non-fundamental mode propagation and methods for use therewith

According to some embodiments, a waveguide cable includes a dielectric core and a conducting layer surrounding the dielectric core. A first antenna may be provided at a first end of the waveguide cable to receive a digital signal and to propagate an electromagnetic wave through the dielectric core. A second antenna may be provided at a second end of the waveguide cable, opposite the first end, to receive the electromagnetic wave from the dielectric core and to provide the digital signal.

Flexible waveguide cable with a dielectric core

As computer clock speeds continue to increase at a rate dictated by Moore's Law, the system buses must also scale in proportion to the processor speed. As data rates increase beyond ~5 Gb/s, the historical methods used to model transmission lines start to break down and become inadequate for the proper prediction of signal integrity. Specifically, the traditional approximations made in transmission line models, while perfectly adequate for slower speeds, do not properly account for the extra losses caused by surface roughness and do not model the frequency dependence of the complex dielectric constant, producing incorrect loss and phase-delay responses, as well as noncausal waveforms in the time domain. This paper will discuss the problems associated with modeling transmission lines at high frequencies, and will provide a practical modeling methodology that accurately predicts responses for very high data rates.

Multigigahertz Causal Transmission Line Modeling Methodology Using a 3-D Hemispherical Surface Roughness Approach

This paper discusses the modeling techniques to account for transmission line high frequency effects, and proposes a method to integrate these techniques into a practical and design-worthy model generation flow. The frequency tabulated transmission line models are capable of predicting wideband dielectric characteristics and high frequency conductor losses due to skin effect and surface roughness. They can be used to accurately model high volume, low cost printed circuit board traces which often have roughened trace surfaces and pronounced frequency variation in dielectric properties. The model accuracy is verified up to 20 GHz in frequency domain, thus suitable for Multi-Gigabit signaling analysis.

A Practical Method for Modeling PCB Transmission Lines with Conductor Surface Roughness and Wideband Dielectric Properties

SEM photographs of a typical copper conductors prepared by the PCB industry exhibit a 3-D "snowball" structure of copper surface distortions. We have developed an analytical basis for the electromagnetic scattering by the copper "snowballs" to predict additional power losses to those presented by the propagating medium that compare well with the observed measurements for a set of rough microstrip lines. In this paper we describe the fundamental concepts involved with the 3D scattering theory of our analysis.

Stephen H. Hall

Papers

Advanced Signal Integrity for High-Speed Digital Designs

Flexible waveguide cable with a dielectric core

Multigigahertz Causal Transmission Line Modeling Methodology Using a 3-D Hemispherical Surface Roughness Approach

A Practical Method for Modeling PCB Transmission Lines with Conductor Surface Roughness and Wideband Dielectric Properties

Fundamentals of a 3-D “snowball” model for surface roughness power losses