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This paper describes an antenna design that is suitable for microwave imaging and radar applications. Microwave imaging technology has attracted many interests nowadays and it has been used in a variety of applications such as: non-destructive testing and evaluation, through-the-wall imaging, concealed weapon detection at security check points, structural health monitoring and medical imaging. Similarly, radar-based applications have been popular in many areas. The basic idea of using microwave imaging and radar systems is to transmit electromagnetic waves from a transmitting antenna to the target material and receive the scattered waves at a receiving antenna. For this reason, the choice of the antenna plays an important role for the system. There is a need for compact sized, low cost and high efficiency antennas which can radiate ultra-wideband signal to transmit short pulses. Furthermore, these antennas should have similarly end-fire radiation pattern to obtain good resolution of the produced images for using both in imaging systems and radar applications. In this study, firstly a conventional compact-sized rectangular patch antenna is designed. Then, various optimizations are performed on that antenna by using High Frequency Structural Simulator (HFSS) software. After that, this antenna is fabricated and tested with Vector Network Analyzer. The fabricated antenna has a simulated and measured bandwidth from 4 GHz to 9 GHz for |S11|<10 dB, respectively. The return loss results show that the good impedance matching is obtained through the working frequency band. The proposed antenna has nearly stable end-fire radiation patterns throughout the frequency range. All of the results exhibit that the designed antenna can be used in high range radar applications and is a good candidate for microwave imaging applications.

International Conference on Advanced Technologies, Computer Engineering and Science
ICATCES

Ali Recai Çelik M.Bahattin Kurt Selcuk Helhel

Today, approximately 200 million people around the world are required to regularly check blood sugar levels every day, and this number is increasing day by day. If hyperglycaemia and hypoglycemia occur as a result of blood sugar level abnormalities, serious tissue and organ damage and, most importantly, vital risks can occur. In generally, blood glucose level measurement methods are divided into three categories, which are invasive, minimally invasive and non-invasive. In invasive methods people need to measure blood glucose levels by drilling their fingers, squeezing blood droplets on test strips and treating the results with portable glucometers. The process can be uncomfortable and complicated and has to be repeated many times each day. By using minimally invasive methods, the glucose ratio is determined by the help of tissue fluid or very little blood. Actually this method is uncomfortable for human life too. For this reason, there is a growing need for a new generation of non-invasive glucose-level monitoring systems in which the glucose level can be reliably determined. The goal of the ongoing works in literature are to prevent or delay early diagnosis and complications, rather than to treat the diabetes. This review giving a comprehensive knowledge about non-invasive design methods used in the literature.General definitions are given for each of the design methods. Scientists, laboratories and universities have been working on the design of non-invasive glucometer with various methods, yet there is no product that can measure with high accuracy.

International Conference on Advanced Technologies, Computer Engineering and Science
ICATCES

Ercan Mengüç Selcuk Helhel

Detection of the breast cancer at the early stage has gained much attention over last decades. In this paper, a simulation study of a radar-based ultra-wideband microwave system is presented to detect breast cancer tumors. The main principle of this technique is based on the significant difference in the dielectric properties of malignant breast tumors and normal breast tissue in the microwave frequencies. The tumor’s electrical properties, in particular conduction and specific absorption rate (SAR), change significantly from those of healthy biological tissue when exposed to microwave radiation. In the measurements, a simple planar breast phantom that consisted low dielectric constant material to represent the fat tissue and high dielectric constant material to represent the tumor is used. An ultra-wideband and high gain antenna is used to measure electromagnetic field data for tumorous and non-tumorous breast tissue. According to the obtained results, the used antenna and microwave system are successful for detecting the breast cancer tumor. Measurement system is developed by using High Frequency Structural Simulator (HFSS) software. Antenna design parameters, properties of the breast phantom, analysis and measurement results are demonstrated and explained clearly in the paper.

International Conference on Advanced Technologies, Computer Engineering and Science
ICATCES

Ali Recai Çelik M.Bahattin Kurt Selcuk Helhel