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The Reflector, November 2020
Magnetics Society and co-host Magnetics Society Richmond Chapter – 4:00PM, Tuesday, November 17
Methods for Permittivity, Permeability, and Loss Measurements of Polymer Composite Magneto-dielectric Laminates Please Join us on Tuesday, November 17th, at 4 pm for the November installment of the 2020-2021 Boston’s IEEE Magnetics Society! Due to the COVID-19 situation we will be meeting via zoom/WebEx. Zoom/WebEx link and registration info (registration is free) will be posted to our website one week before the talk. See below for more details. Registration: https://events.vtools.ieee.org/m/245884 Allen F. Horn III, Research Fellow Christopher J. Caisse, R&D Engineer Patricia A. LaFrance, Sr. Engineering Assistant Karl E. Sprentall, Business Development Manager Rogers Corporation, Advanced Connectivity Solutions, Lurie R&D Center, Rogers, CT USA
in a material impedance significantly lower than freespace and a reduction in both bandwidth and antenna efficiency of microstrip patch antennas. A recently developed PTFE – ferrite powder composite laminate exhibits μ_R~ ε_R~ 6 and low electrical and magnetic loss values at frequencies up to 500 MHz. This material has a miniaturization factor of a dielectric material with permittivity of 36, but with an impedance essentially matched to free space. Accurately measuring the permittivity, permeability, and loss values, however, presents challenges.
In the present work, we compare data from widely different test methods, including the Keysight Impedance Analyzer with 16453A and 16454A permittivity and permeability fixtures, coaxial airline perturbation, “full sheet resonance,” and phase length, insertion loss and impedance of microstrip transmission lines over a frequency It has been well known for more than 50 years to use range of 40 MHz to 4 GHz. We explain the causes of high dielectric constant copper clad laminates to reduce both random measurement error and systematic error the size of wavelength dependent microstrip structures in the various test methods. such as patch antennas. In the general case, the material’s impedance is (√(μ_R/ε_R ))x(√(μ_0/ε_0 )) where BIO: Allen F. Horn, III Research Fellow, received a μ_R and ε_R are the relative permeability and permit- BSChE from Syracuse University in 1979, and a Ph. tivity, respectively, and the subscript 0 values are those D. in chemical engineering from M.I.T. in 1984. Prior of free space. The miniaturization factor (by which the to joining the Rogers Corporation Lurie R&D Center in material decreases the wavelength of an EM signal) is 1987, he worked for Dow Corning and ARCO Chemical. √(μ_R ε_R ). While all-natural solid materials exhibit an He is an inventor/co-inventor on 17 issued US patents ε_R value > 1, most materials are non-magnetic, with in the area of ceramic or mineral powder-filled polymer a μ_R = 1.0. Thus, the high dielectric constant results composites for electronic applications.
