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In this study, the numerical analysis and designs of microstrip implant antenna structures for MICS-band (Medical Implant Communication Systems band; 402-405 MHz) and ISM-band (Industrial, Scientific and Medical band; 2.4-2.48 GHz) medical communication applications are evaluated and simulation and measurement results of the proposed dual-band implant antenna are included. Within the scope of the study, first of all, general evaluations about operating bands allocated for medical applications, implant antennas with different radiation geometries, and specific absorption rate (SAR) were made and the features that an implant antenna should have, were presented. By comparing the real tissue and skinmimicking gel methods used to measure microstrip implant antennas in the laboratory environment, the pros and cons were also discussed. Finally, modeling approaches, numerical analysis and measurement results of an exemplary MICS/ISM-band implant antenna were given. Simulations have been carried out with the CST-MWS, which is based on the finite integral method in time domain. Measurements of the implant antenna, fabricated using RO3210 (r=10.2) dielectric material, in MICS and ISM band skin mimicking liquids proposed in the literature were performed. It has been observed that the measurement and simulation results are fairly compatible, except for some frequency shifts and level differences due to fabrication and measurement tolerances. The measured implant antenna with fractional bandwidths of 77% and 15% respectively in MICS and ISM bands, compact size of 10.6×10×1.27 mm3 and low SAR values compatible with international standards, is a good alternative that can be used in dual-band implant communication applications. [ABSTRACT FROM AUTHOR]

In this study, x band microstrip ring patch antenna was designed and its performance was investigated under various types of feeding methods and dimensions. The patch dimensions and dielectric base thickness were kept constant. The simulations were performed by using Ansys HFSS programme. In simulations, FR-4 and Rogers RT-5880 dielectric base materials were preferred. The bandwidth of the antennas changes between 260 to 1160 MHz and the gain of the antennas are between 4.6 and 9.35 dB. [ABSTRACT FROM AUTHOR]

XLPE dielectric materials have an important place in electricity transmission and distribution. The aging of XLPE dielectric materials during the service period is inevitable. The surface properties of XLPE dielectric materials play an active role in the determination and evaluation of their service life. Properties such as hydrophobicity and hydrophilicity are the methods used in the analysis of the surface properties of materials. Within the scope of this project, contact angle measurements were carried out under the electric field for evaluation and determination on the wettability behavior of the XLPE material, which plays an important role in electrical insulation, which is widely used in electrical energy transmission and distribution. In the contact angle measurement platform manufactured using the 3D printer, XLPE insulator was placed between the aluminum plane electrodes and exposed to an electric field. A high voltage source of 0-10kV was used as a high voltage generator during the experiments. Snapshots of the 1.8M saltwater droplet dropped on the XLPE insulator surface under the electric field were taken. In the image processing part of the study, images taken with a digital microscope were processed using the image processing techniques with the help of a graphical user interface (GUI) prepared on the MATLAB platform. Contact angle values were obtained as output. Contact angles obtained from XLPE surfaces under the electric field will allow an evaluation of the service life of XLPE dielectric materials. An approach based on the contact angle for evaluation and determination of the wettability of XLPE dielectric materials is presented. As a result, the correlation between the electric field, wettability, and contact angle was observed. [ABSTRACT FROM AUTHOR]

With developing technology, applications in agricultural products are becoming more common. The main dominant parameter in these applications is the determination of the dielectric property of the plant material. Because how the electromagnetic (EM) wave penetrating the material interacts with the material depends on its dielectric properties. The ability of remote sensing (RS) and drying and heating technologies to increase efficiency and quality in production is related to the dielectric characteristics of the material. In this study, the dielectric parameters of leaves of apricot and plum trees made widely produced in Turkey are measured by using the transmission line technique. Measurements are conducted between 3.30-4.90 GHz (for WR229 waveguide) and dielectric characteristics of apricot and plum leaves depending on moisture content and frequency are investigated. A new model is proposed by a curve fitting method based on frequency and moisture content using dielectric measurement data of apricot leaves. This model is compared with the dielectric measurement results of the plum leaves of the same family as the apricot type and the accuracy of the proposed model is tested. To make sure the performance of the model well enough, the coefficient of determination R2 and Mean Square Root of Error (RMSE) values are obtained as 0.996 and 0.653, respectively. [ABSTRACT FROM AUTHOR]