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Showing papers in "International Journal of Rf and Microwave Computer-aided Engineering in 2019"


Journal ArticleDOI
TL;DR: In this article, an exhaustive survey on the different RFEH system that is reported is carried out and important design issues are identified with insights drawn.

81 citations




Journal ArticleDOI
TL;DR: In this article, a polarization independent broadband metamaterial absorber (MA) structure based on split ring resonators which are loaded with lumped elements and via connection lines is proposed.
Abstract: Correspondence Mehmet Bakır, Faculty of Engineering and Architecture, Department of Computer Engineering, Bozok University, Yozgat, Turkey. Email: mehmet.bakir@bozok.edu.tr Abstract A new polarization independent broadband metamaterial absorber (MA) structure based on split ring resonators which are loaded with lumped elements and via connection lines is proposed. The designed structure shows a perfect absorption between 4 and 16 GHz which is validated by simulation studies. Experimental study is only made for the structure that has no via connections and no the lumped element resistors to show the importance of these entities in the proposed metamaterial structure. Both numerical and experimental study results show that broadband MA property depends on the resistors and via connections on the proposed structure. By having high absorption in a wideband range which is numerically demonstrated, the proposed structure can be used in energy harvesting or wireless power transfer applications with higher efficiencies.

41 citations



























Journal ArticleDOI
TL;DR: Based on a simple and effective calculation method, two free-space measurement setups are employed to investigate the dielectric properties of various materials at terahertz (THz) frequencies as discussed by the authors.
Abstract: Funding information Research Grants Council of the Hong Kong SAR, China, Grant/Award Number: T42-103/16-N Abstract Based on a simple and effective calculation method, two free-space measurement setups are employed to investigate the dielectric properties of various materials at terahertz (THz) frequencies. One setup involves THZ time-domain spectroscopy (THz-TDS) at a frequency range of 0.4 to 1 THz. The other setup comprises a vector network analyzer (VNA) with pairs of VAN extenders (VNAXs) and diagonal standard gain horns (SGHs) at a frequency range of 0.22 to 1.1 THz. The calculation method is verified for the THz-TDS system and employed in the VNA system for the first time. Dielectric properties, including refractive indices, power absorption coefficients, relative permittivities, and loss tangents, are calculated from measured transmission data. Several materials, including printed circuit boards and 3D printing materials, are characterized to verify the calculation method and compare the measurement setups.