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Article
Publication date: 16 November 2012

Allen F. Horn, Patricia A. LaFrance, John W. Reynolds and John Coonrod

The purpose of this paper is to help high frequency circuit designers understand how to choose the best permittivity value for a laminate material for accurate modeling.

Abstract

Purpose

The purpose of this paper is to help high frequency circuit designers understand how to choose the best permittivity value for a laminate material for accurate modeling.

Design/methodology/approach

In this paper, experimental measurements of the performance of simple circuits are compared to various mathematical and software models.

Findings

Higher permittivity values were obtained using samples with bonded copper foil compared to samples etched free of foil. These higher values yielded better agreement between measured and modelled performance using current automated design software. High profile foil on thin laminates was found to increase the surface impedance of the conductor and change the propagation constant and apparent permittivity of the laminate by 15 percent or more. It was also demonstrated that, under some circumstances, the anisotropy of the substrate could result in differences in measured and modelled performance.

Research limitations/implications

Only a limited number of circuit laminate materials were closely examined. Future work should include a wider variety of laminates.

Originality/value

The paper details the magnitude of the effects of test method, conductor profile and substrate anisotropy on the values of a material's permittivity best suited for circuit design purposes.

Details

Circuit World, vol. 38 no. 4
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 22 November 2011

Christopher J. Caisse, John Coonrod and Allen F. Horn

The purpose of this paper is to quantify the effects of thermal conductivity (TC), dielectric constant and dissipation factor (DF) of circuit laminates on the temperature rise…

Abstract

Purpose

The purpose of this paper is to quantify the effects of thermal conductivity (TC), dielectric constant and dissipation factor (DF) of circuit laminates on the temperature rise with active components and RF trace heating.

Design/methodology/approach

Temperature rise measurements were made on surface mounted chip resistors (to simulate active components) at various dissipated power levels, with and without “via farms”. The RF heating temperature rise of 50 ohm microstrip transmission lines on 0.5 mm laminates was also measured by the same method.

Findings

The chip resistor temperature rise correlated with the independently measured TC of the laminate materials. The use of a “via farm” substantially reduced the temperature rise in all materials, but the higher TC laminates still conferred a measurable advantage. The trace temperature rise due to RF heating correlated with both TC and DF.

Research limitations/implications

It was shown that the one‐dimensional heat transfer model does not accurately calculate the temperature rise due to significant in‐plane heat spreading, particularly with lower TC materials.

Originality/value

This paper details how temperature rise of both active components and 50 ohm transmission lines is affected by the thermal and electrical properties of the circuit laminate.

Content available
Article
Publication date: 28 January 2014

Jan Vanfleteren

90

Abstract

Details

Circuit World, vol. 40 no. 1
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 1 April 2003

Georgios I. Zekos

Aim of the present monograph is the economic analysis of the role of MNEs regarding globalisation and digital economy and in parallel there is a reference and examination of some…

91346

Abstract

Aim of the present monograph is the economic analysis of the role of MNEs regarding globalisation and digital economy and in parallel there is a reference and examination of some legal aspects concerning MNEs, cyberspace and e‐commerce as the means of expression of the digital economy. The whole effort of the author is focused on the examination of various aspects of MNEs and their impact upon globalisation and vice versa and how and if we are moving towards a global digital economy.

Details

Managerial Law, vol. 45 no. 1/2
Type: Research Article
ISSN: 0309-0558

Keywords

Book part
Publication date: 13 August 2018

Robert L. Dipboye

Abstract

Details

The Emerald Review of Industrial and Organizational Psychology
Type: Book
ISBN: 978-1-78743-786-9

Abstract

Details

Traffic Safety and Human Behavior
Type: Book
ISBN: 978-1-78635-222-4

Abstract

Details

Central Bank Policy: Theory and Practice
Type: Book
ISBN: 978-1-78973-751-6

Book part
Publication date: 10 June 2014

Abstract

Details

Practical and Theoretical Implications of Successfully Doing Difference in Organizations
Type: Book
ISBN: 978-1-78350-678-1

Book part
Publication date: 24 July 2020

Lillian T. Eby, Melissa M. Robertson and David B. Facteau

Interest in employee mindfulness has increased dramatically in recent years, fueled by several important conceptual articles, numerous studies documenting the benefits of…

Abstract

Interest in employee mindfulness has increased dramatically in recent years, fueled by several important conceptual articles, numerous studies documenting the benefits of mindfulness for employee outcomes, and the adoption of mindfulness-based practices in many Fortune 500 organizations. Despite this growing interest, the vast majority of research on employee mindfulness has taken an intrapersonal focus, failing to appreciate the ways in which mindfulness may enhance work-related relational processes and outcomes. The authors explore possible associations between mindfulness and relationally oriented workplace phenomena, drawing from interdisciplinary scholarship examining mindfulness in romantic relationships, child–parent relationships, patient–healthcare provider relationships, and student–teacher relationships. A framework is proposed that links mindfulness to three distinct relationally oriented processes, which are expected to have downstream effects on work-related relational outcomes. The authors then take the proposed framework and discuss possible extensions to a variety of unique workplace relationships and discuss critical next steps in advancing the relational science of mindfulness.

Details

Research in Personnel and Human Resources Management
Type: Book
ISBN: 978-1-80043-076-1

Keywords

Book part
Publication date: 22 May 2017

Brenda Jones Harden, Brandee Feola, Colleen Morrison, Shelby Brown, Laura Jimenez Parra and Andrea Buhler Wassman

Children experience toxic stress if there is pronounced activation of their stress-response systems, in situations in which they do not have stable caregiving. Due to their…

Abstract

Children experience toxic stress if there is pronounced activation of their stress-response systems, in situations in which they do not have stable caregiving. Due to their exposure to multiple poverty-related risks, African American children may be more susceptible to exposure to toxic stress. Toxic stress affects young children’s brain and neurophysiologic functioning, which leads to a wide range of deleterious health, developmental, and mental health outcomes. Given the benefits of early care and education (ECE) for African American young children, ECE may represent a compensating experience for this group of children, and promote their positive development.

Details

African American Children in Early Childhood Education
Type: Book
ISBN: 978-1-78714-258-9

Keywords

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