The study focuses on coplanar metamaterial lines and resonators and the possibility to increase their performances. To achieve our goal, we studied these structures accesses for a better adaptation. This study allowed us to optimize the accesses of meta-lines components. We thus obtain a possibility of cells which it is necessary to decrease the losses in meta-lines structures.

The main objective of this research work is the comparison of the two Van Der Pauw four-point measurement configurations (aligned and square) commonly used to measure the resistivity of metal thin films which are widely used in the manufacture of planar components such as inductors, transformers, insulators, circulators, etc. Electrical characterization is very important because it ensures the quality of the metal supposed to conduct electrical current in the components mentioned above. The resistivity measured by using the square or aligned configuration sometimes has significant differences. Making a comparative study therefore allow to know which gap between points, which frequencies to choose when measurements must be made by using square or aligned configuration. In this paper, the measured thin films are made of copper which is broadly used in the structures because of its physical, chemical and mechanical properties [1]. The copper is deposited on alumina substrates by magnetron radiofrequency sputtering. Rectangular alumina substrates of dimensions 50mm x 20mm x 635μm were used. Thin film resistivity measurements using a four-point measurement method were performed by using HP 4284A LCRmeter in the frequency range of a few Hz to a few kHz. The comparison was made between the four-point aligned method and the four-point square method based on the frequency, the gap between points and the thin film thickness was made. The results obtained by the study show that both configurations measure the same resistivity up to 1 kHz and then the increase of resistivity in aligned configuration limits its use beyond this frequency. The square configuration can still measure the same resistivity up to 40 kHz. The study also shows that the gap between points is limited to 3 μm in aligned configuration while the square configuration allows a gap up to 5 μm.

The objective of this work research is the use of four-point measurements and so-called Van Der Pauw methods in measuring the resistivity of copper thin films widely used in the manufacture of planar components such as inductor and others. Aligned configuration and square configuration are commonly used to measure thin films resistivity before use. But differences in values between the two configurations according to frequency and thickness were observed according to the authors. Measurements with both configurations on the same thin films must make it possible to know measurements evolution as a function of frequency and thickness. The observation of measuring frequency ranges of each configuration and the minimum thicknesses to have solid copper resistivity are the main contributions of the paper. This electrical characterization is carried out on copper thin films deposited on alumina substrates (50 mm × 20 mm × 635 μm) using RF sputtering technique. Copper thin films with various thicknesses (3.3 μm, 3.6 μm and 5.2 μm) were characterized. Low-frequency electrical characterization of these thin films was performed by four-point measurement method and using an HP 4284A type LCRmeter over the frequency range of 20 Hz to 1 MHz. Van der Pauw's method was used to calculate resistivity. These studies allowed us to know influence of measurement configurations and influence of parameters such as frequency and thickness of the copper thin films on resistivity.

Materials with specific electromagnetic properties are increasingly used for the realization of passive components. Therefore, electromagnetic characterization is a priority to know these materials properties. This study focuses on the electromagnetic characterization of 10 nm maghemite ferrofluid doped sol-gel using a resonant cavity method. We deposited the sol-gel by dipping/removal on an alumina substrate in order to make measurements on the cavity to determine the complex permittivity and permeability. Two studies were carried out; the first consisted in varying the doped sol-gel thickness of layers of the same concentration in the realization of samples; and the second consisted in varying the volume concentration of ferrofluid according to the matrix dimensions. The first study showed that the dielectric constants do not vary with the thickness of the magnetic sol-gel layers. In the second study, measurements also showed that the gyromagnetic resonance is the same for all samples regardless of the ferrofluid volume concentration.