Planar lightwave integrated circuits with embedded actives for board and substrate level optical signal distribution

© 2004 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.DOI: 10.1109/TADVP.2004.831894As the data rate of integrated circuits dramatically increases, interconnection speed at the backplane and board levels are beginning to limit system performance, which drives investigations into alternative interconnection technologies. Critical factors to consider when evaluating alternative interconnection approaches include interconnect speed, power consumption, area, and compatibility with current backplane and board integration technologies. Optical interconnections can achieve very high speed with a significant reduction in interconnect footprint compared to transmission lines, robust signal quality in high-density interconnection systems because of immunity to electromagnetic interference, and potentially simple to design (compared to transmission lines) lines with materials which can be postprocessed onto printed wiring boards or integrated into the board structure. This paper explores design options for planar optical interconnections integrated onto boards, discusses fabrication options for both beam turning and embedded interconnections to optoelectronic devices, describes integration processes for creating embedded planar optical interconnections, and discusses measurement results for a number of integration schemes that have been demonstrated by the authors. In the area of optical interconnections with beams coupled to and from the board, the topics covered include integrated metal-coated polymer mirrors and volume holographic gratings for optical beam turning perpendicular to the board. Optical interconnections that utilize active thin film (approximately 1-5 µm thick) optoelectronic components embedded in the board are also discussed, using both Si and high temperature FR-4 substrates. Both direct and evanescent coupling of optical signals into and out of the waveguide are discussed using embedded optical lasers and photodetectors

A 0.18 mu m CMOS fully integrated 6.25Gbps single aggressor multi-rate crosstalk cancellation IC for legacy backplane and interconnect applications

A multi-rate crosstalk canceller for active cancellation of near end cross talk (NEXT) caused by a single aggressor in a backplane channel environment has been demonstrated in this paper. The proposed IC enhances the performance of existing legacy backplane at higher data rates, thereby avoiding the costs associated with upgrading to higher end backplanes and connectors. The IC has been fabricated in a 0.18??m CMOS process and the prototype test bench demonstrated capability of improving the bit-error rate (BER) performance in excess of 5 orders of magnitude at data rates up to 6.25Gbps

Realization of multigigabit channel equalization and crosstalk cancellation integrated circuits

In this paper, we present integrated circuit solutions that enable high-speed data transmission over legacy systems such as short reach optics and electrical backplanes. These circuits compensate for the most critical signal impairments, intersymbol interference and crosstalk. The finite impulse response (FIR) filter is the cornerstone of our architecture, and in this study we present 5- and 10-Gsym/s FIR filters in 2-mum GaAs HBTs and 0.18-mum CMOS, respectively. The GaAs FIR filter is used in conjunction with spectrally efficient four-level pulse-amplitude modulation to demonstrate 10-Gb/s data throughput over 150 in of 500 MHz(.)km multimode fiber. The same filter is also used to demonstrate equalization and crosstalk cancellation at 5 Gb/s on legacy backplane. The crosstalk canceller improves the bit error rate by five orders of magnitude. Furthermore, our CMOS FIR filter is tested and demonstrates backplane channel equalization at 10 Gb/s. Finally, building blocks for crosstalk cancellation at 10 Gb/s are implemented in a 0.18-mum CMOS process. These circuits will enable 10-Gb/s data rates on legacy systems.close354

Engineering online and in-person social networks to sustain physical activity: application of a conceptual model

BACKGROUND: High rates of physical inactivity compromise the health status of populations globally. Social networks have been shown to influence physical activity (PA), but little is known about how best to engineer social networks to sustain PA. To improve procedures for building networks that shape PA as a normative behavior, there is a need for more specific hypotheses about how social variables influence PA. There is also a need to integrate concepts from network science with ecological concepts that often guide the design of in-person and electronically-mediated interventions. Therefore, this paper: (1) proposes a conceptual model that integrates principles from network science and ecology across in-person and electronically-mediated intervention modes; and (2) illustrates the application of this model to the design and evaluation of a social network intervention for PA. METHODS/DESIGN: A conceptual model for engineering social networks was developed based on a scoping literature review of modifiable social influences on PA. The model guided the design of a cluster randomized controlled trial in which 308 sedentary adults were randomly assigned to three groups: WalkLink+: prompted and provided feedback on participants’ online and in-person social-network interactions to expand networks for PA, plus provided evidence-based online walking program and weekly walking tips; WalkLink: evidence-based online walking program and weekly tips only; Minimal Treatment Control: weekly tips only. The effects of these treatment conditions were assessed at baseline, post-program, and 6-month follow-up. The primary outcome was accelerometer-measured PA. Secondary outcomes included objectively-measured aerobic fitness, body mass index, waist circumference, blood pressure, and neighborhood walkability; and self-reported measures of the physical environment, social network environment, and social network interactions. The differential effects of the three treatment conditions on primary and secondary outcomes will be analyzed using general linear modeling (GLM), or generalized linear modeling if the assumptions for GLM cannot be met. DISCUSSION: Results will contribute to greater understanding of how to conceptualize and implement social networks to support long-term PA. Establishing social networks for PA across multiple life settings could contribute to cultural norms that sustain active living. TRIAL REGISTRATION: ClinicalTrials.gov NCT0114280