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1 – 2 of 2Allen 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