Thickness-Independent Automated Constitutive Parameters Extraction of Thin Solid and Liquid Materials From Waveguide Measurements

Abstract

Abstract-The constitutive parameters measurement of thin solid and liquid materials by transmission-reflection methods generally suffers from a) the requirement of the transformation of measured scattering parameters from the reference plane to the end surfaces of the material (measurement plane) and b) inaccurate knowledge on the length of the material, if the material does not fill the entire measurement cell (a waveguide or coaxial-line section). In this research paper, a microwave waveguide method for constitutive parameters determination of these materials is proposed to simultaneously eliminate these problems. There are three main advantages of the proposed method as: a) it explicitly determines the constitutive parameters from measured S-parameters; b) it does not require the knowledge about sample length since it directly measures it as a byproduct of the method; and c) it offers a self-checking feature to trace the performance and accurateness of measurements. This feature does not depend on the constitutive parameters of the sample. We measured the complex permittivity of some thin solid and liquid test samples for validation of the method.

Permittivity Measurement of Thin Dielectric Materials From Reflection-Only Measurements Using One-Port Vector Network Analyzers

“…A general purpose waveguide measurement set-up is used for validation of the proposed method [22,29,36]. Because, in our laboratory, we do not have a one-port network analyzer, we could not directly test the proposed method using a one-port network analyzer.…”

“…We have recently proposed a method to eliminate any errors arising from inaccurate knowledge of sample location inside the waveguide [29]. Although it is attractive and feasible, it experiences problems arising from imprecise information about both electrical properties and length of sample holders.…”

Pulse Reflection From a Dielectric Discontinuity in a Rectangular Waveguide

“…The physical interpretation of R sc (t) may now be readily explained. The first term in (15) represents the initial reflection from the air-dielectric interface. Because no information about the second interface yet exists, it is exactly the interfacial reflection coefficient Γ(t).…”

“…Pulse propagation in inhomogeneously filled guides has received far less attention [9,10], even though partially-filled guides are often used for determining the constitutive parameters of material samples [11][12][13][14][15]. Recently, Moradi and Abtipour [16] proposed using time-domain methods to extract the material parameters of waveguide samples.…”

Thickness-Independent Complex Permittivity Determination of Partially Filled Thin Dielectric Materials Into Rectangular Waveguides

“…Various microwave techniques have been proposed to determine these properties of material under test [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. These methods can be divided into two groups as a) resonant and b) nonresonant methods [1].…”