Alper Caliskan

Development of signal processing techniques for through-wall imaging radar systems

This paper presents some adaptive signal processing and synthetic aperture radar (SAR) imaging techniques for ultra-wide band (UWB) ground penetrating radar. Novel UWB antenna structures are used in this work. Raw and processed data collected by experimental studies of through-wall imaging (TWI) scenarios are demonstrated in B-scan and C-scan target detection images.

High resolution signal processing techniques for millimeter wave short range surveillance radar

In this paper, we investigated adaptive signal processing algorithms for high-resolution imaging of short range targets by 24 GHz millimeter wave (MMW) surveillance radar system. For test measurements, a step frequency continuous wave (SFCW) based Synthetic Aperture Radar (SAR) imaging system has been developed by using Anritsu MS4644A Vector Network Analyzer (VNA) and A-scan radar data were collected to demonstrate B-scan target images. We applied SAR processing and MUSIC (Multiple Signal Classification) algorithm for raw data to enhance the cross-range and range resolutions, respectively. The fusion of SAR and MUSIC algorithms is proposed to obtain improved image quality for better target identification and false alarm rate performance.

Microstrip SIW patch antenna design for X Band Application

In this paper, designs of both circular and octagonal microstrip patch antennas are presented on the Substrate Integrated Waveguide (SIW) for X- Band Applications. Both antennas are modelled and simulated using the full -wave simulator CST MWS. It can be concluded that the proposed antenna designs are able to achieve high gain and directivity with the miniature, compact, light, cost effective and easy to fabricate structures.

Impacts on signal processing techniques for ground penetrating radar

This paper presents some important signal processing techniques for ground penetrating radar. Novel ultrawide band antennas are experimentally designed in this work. Obtained data from experimental studies are presented and used for B-scan and C-scan images.

24 GHz short range radar system measurements for synthetic aperture radar imaging

In this paper, 24 GHz short-range radar measurements and synthetic aperture radar (SAR) imaging results are presented. The designed radar system has one transmitter and one receiver channel and 24 GHz output carrier signal is modulated with 50 MHz square wave at the transmitter channel. In the measurement, horn antennas are used for synthetic radar imaging and A-scan data were obtained with 90 m range. We applied SAR imaging algorithm in order to improve the image resolution to raw B-scan data. Raw and processed data are demonstrated comparatively for target detection performance.

Design of displaced and circular polarized Waveguide Slot Array antenna with dielectric for K-band radar application

In this paper we design an effective Waveguide Slotted Array (WSA) antennas for K-band radar application. First of all, WSA parameters such as waveguide dimensions, slot length, slot width, slot displacement and other parameters of the antenna are calculated by using analytic techniques for 25 GHz. After, in order to suppress side lobe level Taylor and Chebyshev coefficients are determined in detailed and then we calculate slot displacements for each slot. The antennas are simulated according to Taylor and Chebyshev coefficient to obtain low side lobes and also reach effective result, which have high efficiency, high gain and small size, for 25 GHz. Sixteen and thirty-six slots are used to obtain desired results like high gain and narrow beam width at the H-plane. According to simulation results, the antennas which have sixteen and thirty-six slots presents 15.9 and 19.3 dBi realized gains, −17.2 and −16.1 dB side lobe levels (SLL), 9.6 and 4.1 deg. half power beam widths at 25 GHz, respectively. The most significant part of this paper is that change of antenna polarization. Normally longitudinal slots have linear polarization and to obtain circular polarization inclined or cross slot are used. However, these slot structure require complex analytic approach and optimization of the structure takes a lot of time. So, effective approach to change antenna polarization are presented.

Experimental study of human respiratory detection using UWB GPR

Todays, Ground Penetrating Radar (GPR) System is used for civil applications such as detection of buried pipes, mine and military fields. One of the recent applications of GPR in civil and defense industry is detection of human vital signs through obstacles such as wall, rubble etc. In this study, we aim to set ultra-wideband ground penetrating radar system for detection human vital signs. For this purpose, system parameters will be designed and data acquisition will be performed successfully. For signal extraction of respiratory motion, Fast Fourier Transform will be applied on radar data.

Design of Dielectric Lens Loaded Double Ridged Horn Antenna for Millimetre Wave Application

In this paper, designs of Dielectric Lens Loaded Double Ridged Horn Antenna for Millimetre Wave Applications is investigated. Firstly a double ridged horn antenna is designed and simulated in CST environment. After that, 2 dielectric lens architecture are designed and placed at the aperture of the antenna. It is seen that by placing spherical shaped dielectric lens, it is possible to achieve improvement in return loss and farfield gain of the antennas design in a 20–40 GHz bandwidth.

Coplanar stripline-fed Microstrip Yagi-Uda antenna for ISM band application

In this paper, design and experimental results of a coplanar stripline fed Microstrip Yagi-Uda antenna are presented. The proposed antenna consists of a microstrip line to coplanar stripline transition, reflector microstrip patch, coplanar stripline-fed driver dipole, and three director microstrip patches on low-cost FR4 with the relative permittivity 4.4, thickness 1.58mm, loss tangent 0.025. The 10-dB bandwidth and gain are measured as 130 MHz at the center frequency of 2.45 GHz, 7.5 dBi.

Design and realization of dual band Microstrip Monopole antenna

Herein, design and experimental results of a dual band Microstrip Monopole antenna are presented. The proposed antenna consists of a zig-zag microstrip line as monopole patch alongside of a Defected Ground structure under the fed-line of the antenna for size miniaturization propose, fabricated on FR4. The 10-dB bandwidth and gain performances are measured as 130 MHz and 6 dB at the centre frequency of 2.42 GHz, and140 MHz, and 2dB at the centre frequency of 5.92 GHz respectively.