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Publication Metadata only Assessing Automotive Bumper Materials: A Comparative Study on Attenuation at 77GHz(IEEE, 2024) Neubauer, Michael; Petanjek, David; Hirschmugl, Michael; Kiebach, Helge; Karamzadeh, Saeid; Bahcesehir UniversityHaving information about the materials surrounding the radar sensors is essential in the automotive sector, in order to guarantee good functionality of the sensor. Since automotive manufacturers also start integrating radar sensors behind bumpers, it is essential to know the characteristics of the materials used in bumpers and how a repair of a bumper would alter those characteristics. This paper shows, how the damping characteristics of different samples were measured at 77GHz using a scalar measurement setup and compares the attenuation for different types of paints and modifications.Publication Metadata only Design and analysis of a label-free water-soluble glucose sensor based on suspended hybrid plasmonic micro-ring resonator(IEEE, 2022) Moeinimaleki, Kaveh; Moeinimaleki, Babak; Zarean, Rana; Abedashtiani, Alireza; Karamzadeh, Saeid; Akdeniz University; Bahcesehir UniversityIn this paper, the design and analysis of a label-free water-soluble glucose sensor based on a suspended hybrid plasmonic micro-ring resonator with an external radius of 940 nm in the third telecommunication window to sense the concentration of water-soluble glucose is presented. The simulation results obtained using three-dimensional FDTD show that the sensitivity and the figure of merit values obtained for glucose measurements with concentrations of 0 to 50% in water solution are 218.5 (nm/RIU) and 16.11 (1/RIU), respectively. Comparing the results of the proposed sensor with the previous work, which has four times more footprint, shows that the structure's sensitivity has increased by 17 percent.Publication Metadata only Signal Processing Techniques for Human Vital Signs Sensing by Short Range Radar(IEEE, 2020) Eren, Cansu; Karamzadeh, Saeid; Kartal, Mesut; Istanbul Technical University; Bahcesehir University; Istanbul Technical UniversityAmbient Assistant Living(AAL) applications gain importance considering the aging population in the world. The aim of this study is the analysis of signal localization techniques that extract frequency rates of human breathing in AAL applications. Ultra-wideband radar system has been used to detect respiratory rate due to its high resolution and non-ionizing energy. Experimental scenarios are performed in three cases, and the human body is expected as speaking and hand-waving during scenes. In this way, the realistic situations are have been mimicked. The spectrum analysis of the measured signals is performed by Fast Fourier Transform (FFT) and Hilbert Huang Transform (HHT). The comparison of these techniques is given. Considering non-linearity and non-stationarity of HHT, it is more effective and provides regional analysis.Publication Metadata only Comparison of Six Different Dielectric Substrates in Microstrip Patch Antenna Design(IEEE, 2024) Goksel, Fatih; Karamzadeh, Saeid; Bahcesehir University; Bahcesehir UniversityMicrostrip patch antenna (MSPA) is the most popular antenna type due to the small size, easy to fabricate, simple and inexpensive construction, lightweight and low volume, conformity with planar and non-planar surfaces, dual and triple frequency operation in recent years. Especially, due to the becoming the size of the devices becoming smaller, desire to design MSPA has gained more importance than before. In this study, as a result of comparison between six different types of antennas, showed us which of the substrate or substrates give us the best performance of the newly designed patch antenna could be chosen. Based on this, in this study, designed rectangular MSPA simulated with six different substrates which are FR4 Glass Epoxy with 4.3, ROGERS DT5880 with 2.2, ROGERS 4003C with 3.3, Teflon with 2.1, Arlon AD300A with 3 and last Alumina with 9.9 dielectric constant. The study includes a copper patch antenna and copper ground working at 5.8 GHz. The six substrates are kept constant at 1.6 mm height. Good results gained at the desired frequency of 5.8 GHz antenna which is at the resonant frequency between 5.7-5.9 GHz. The main aim of this study is to support their research and create an idea about the six different substrates which can be prepared by researchers while choosing the substrate of the MSPAs.Publication Metadata only Detection of Human Respiratory and Range by IRUWB Radar(IEEE, 2023) Shakfa, Ali; Esmaeilishahir, Mahdi; Karamzadeh, Saeid; Bahcesehir UniversityThe technology of Impulse Radio Ultra-Wide-Band (IR-UWB) radar is very promising for non-contact sensing applications, such as detecting human vital signs like heart rate (HR) and respiration rate (RR), as well as determining the location of a person. This research paper introduces a technique for detecting the respiration rate and location of a stationary human. The method involves using preprocessing techniques to improve clutter reduction and estimating the frequency domain of the signals. Low pass and bandpass filters as preprocessing methods are presented. The Fast Fourier Transform (FFT) processing method is used to determine the human RR in the frequency domain. The proposed approach is evaluated using a P440 (IR-UWB) radar and shows promising results. The experiments demonstrate that the proposed method is effective in accurately detecting the vital signs of a stationary single or multiple persons.Publication Metadata only A Wearable Circularly Polarized Antenna for 5G Applications(IEEE, 2022) Ibrahim, Assim; Tetik, Evrim; Karamzadeh, Saeid; Bahcesehir University; Istanbul Arel University5G technology for health care is a considerable demand nowadays due to the revolution in IoT devices. A dual-band antenna on a Rogers RT/duroid 5880 substrate with a dielectric constant of 2.2 and thickness of 0.508 mm, is presented for 3.4 GHz and 5.85GHz frequency bands. The top layer of the proposed antenna consists of a square part that includes an inductive meander line. It is connected to an I-shape, which is merged with reversed L-shaped, the higher resonant frequency excited at 3.4 GHz. In the bottom layer, after the reflector is made, the inductive meander line is created and connected to a reversed U-shape. The proposed antenna of size 19 x 12 mm(2) reveals to perform well for frequencies between 3.37 and 3.47 GHz. It has an axial ratio less than 3dBi and a peak gain of 1.7 dBi that increases after adding a multi-layer of a human hand up to 8 dBi.Publication Metadata only X-Band Circularly Polarized Antenna for CubeSat Communication(IEEE, 2023) Karamzadeh, Saeid; Bahcesehir UniversityA compact size high gain circularly polarized patch antenna with polarization diversity is presented for CubeSat communication. The antenna has polarization diversity and could support both Right-Hand Circular Polarization (RHCP) and Left-Hand Circular Polarization (LHCP) at the same time. The impedance bandwidth of the antenna is 27% (7.1GHz - 9.4GHz) which is represented by the S11 result. The axial ratio of the proposed antenna is 23% (7.2GHz - 9.1GHZ) and the gain is 5.5 dBic. The radiation pattern of the antenna convenient for CubeSat is also provided.Publication Metadata only Wide Angle Frequency Scanning Antenna for X-Band Applications(IEEE, 2020) Karamzadeh, Saeid; Rafiei, Vahid; Bahcesehir UniversityBeam Steering antennas are a significant part of the communication systems applications requiring tracking or frequent repositioning. In this work, a new high gain broadband leaky-wave antenna is presented for X-band applications. The impedance bandwidth of the proposed Antenna is 32.65% and the scanning angle is 160 degrees. The fabricated antenna results are in good agreement with the simulation results.Publication Metadata only A Compact Low SAR Value Circularly Polarized Wearable Antenna Design for 5G Applications(IEEE, 2022) Gokdemir, Melih; Saeidi, Tale; Karamzadeh, Saeid; Akleman, Funda; Istanbul Technical University; Bahcesehir UniversityIn this study, a wideband wearable antenna is proposed for 5G and IoT applications. The presented circularly polarized coplanar waveguide antenna has a compact size (16mm x 21.5mm). The other result of the novel design which makes this antenna one of the best choices for wearable applications is its low SAR values. These values are 0.0846 and 0.0497 W/kg for mass densities of 1g and 10g, respectively.Publication Metadata only Metamaterial-Based Circularly Polarized Wearable Antenna for ISM and 5G Communications(IEEE, 2022) Saeidi, Tale; Gokdemir, Melih; Karamzadeh, Saeid; Bahcesehir University; Istanbul Technical UniversityA multiband, small, high gain, low specific absorption rate (SAR), and circularly polarized (CP) textile wearable antenna is designed on a layer of denim (epsilon(r) = 1.3, h = 0.787 mm) substrate. The antenna is comprised of a rectangular patch that feeds through an inset transmission line and four tilted periodic slots to enhance the bandwidth (BW) and achieve circular polarization. A layer of fleece fabric (epsilon(r) = 1.04, h = 3 mm) attached to a layer of full ShieldIt to create maximum directivity and minimize SAR value. Then, the antenna is loaded with six arrays of Split Ring Resonator (SRR) on the same antenna layer to enhance the BW that had been reduced after adding the second layer. The antenna works for both ISM and 5G communication systems as it operates at 2.35-2.45 GHz and 3.3-3.9 GHz, respectively. It has the maximum directive gain of 8.52 dBi, acceptable SAR values for both standards with total dimensions of 54 x 56 mm(2). In addition, the antenna's CP is examined, showing AR values of < 3 dB at the working BW with a decent agreement between the simulation and measurement outcomes.