Browsing by Author "Secmen, Mustafa"

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Citation - Scopus: 1
A Broadband Lens Loaded Vivaldi Antenna for Sub-6 GHz/mm Wave 5G Applications and Wideband Nondestructive Material Characterization
(Institute of Electrical and Electronics Engineers Inc., 2024) Berker Colak; Zeynep Ertekin; Mustafa Seçmen; Colak, Berker; Ertekin, Zeynep; Secmen, Mustafa
This study presents a broadband and compact antipodal Vivaldi antenna design and production having an improved gain characteristic with the addition of a dielectric lens made of PLA. The proposed antenna has measured VSWR of less than 2.1 through the broadband frequency of 3.3-43.5 GHz and has more than 6.5 dBi measured gain above 8.5 GHz (up to 43.5 GHz). The antenna which can fit in a cube with just 4.8 cm edge has low-cost and easy manufacturing. It can meet the need of multiple antennas due to its broad frequency range (from S-band to Ka-band) which covers different applications such as wideband nondestructive material characterization and testing. Since the proposed antenna covers sub-6 GHz (3.3 GHz 5.8 GHz) and mmWave (26 38 41 GHz) 5G frequencies it can be also used in base stations with MIMO or array configuration. © 2024 Elsevier B.V. All rights reserved.
A Differential Evolution Algorithm for the Extraction of Complex Natural Resonance Frequencies of Electromagnetic Targets
(SPRINGER-VERLAG BERLIN, 2011) Mustafa Secmen; M. Fatih Tasgetiren; Secmen, Mustafa; Tasgetiren, M. Fatih; DS Huang; Y Gan; V Bevilacqua; JC Figueroa
This paper presents a differential evolution algorithm in order to find unique resonance frequencies of an electromagnetic target in the resonance scattering region. These frequencies are estimated from the roots of Laplace transform of a specially designed incident signal. The parameters of the signal are computed with an intelligent differential evolution (DE) algorithm. The algorithm searches for minimization of the scattered signal's energy in late-time region which is main fitness function in the algorithm. The proposed algorithm is demonstrated for a scattered signal of a dielectric sphere having several poles. The acquired pole results show very good agreement with theoretical expectations. Besides the differential evolution algorithm has higher accuracy as compared to a similar method which utilizes from genetic algorithm.
A Dual-Band Circularly Polarized Bi-Sectoral Waveguide Horn Antenna for High Power LEOP TT&C Systems
(Institute of Electrical and Electronics Engineers Inc., 2022) Esra Alkın; Ceyhan Türkmen; Mustafa Seçmen; Secmen, Mustafa; Turkmen, Ceyhan; Alkin, Esra
In this study a dual-band circularly polarized bi-sectoral waveguide antenna is proposed which is used launch and early orbit phases (LEOP) of telemetry tracking and command (TT&C) applications of satellite systems to almost cover full space together with omni-directional (toroidal) antennas. The structure consists of four parts (pyramidal horn antennas) each having excited by a single inclined slot being cut over circular waveguide. However because the overall antenna is only fed with a single rectangular waveguide it works as transceiver (in TX and RX bands simultaneously). The parts belonging to each band have bi-directional patterns being opposite to each other. Therefore instead of using four separate antennas each being fed by separate rectangular waveguide to cover both directions in dual band (TX and RX bands) in 3D space one antenna with just one feed is demonstrated as being sufficient for same purpose. For this purpose an antenna is designed for a Ku-band TT&C application. The results show that the antenna is dual-band over 500 MHz bandwidth around 11.75 GHz (TX) and 13.75 GHz (RX) center frequencies. The antenna has more than 9.5 dBi peak gain in both main lobes and 15 dB return loss at TX band, and has more than 10 dBi peak gain and 10 dB return loss at RX band. Besides it has less than 3 dB and 3.5 dB axial ratio (AR) values at TX and RX bands within almost 45º and 60º azimuth and elevation beamwidth values respectively. © 2022 Elsevier B.V. All rights reserved.
Citation - WoS: 1
Citation - Scopus: 1
A Measurement Technique For Determination of Power Levels of Different Propagation Modes in Circular Waveguides
(IEEE, 2020) Ceyhan Turkmen; Esra Alkin; Mustafa Secmen; Secmen, Mustafa; Turkmen, Ceyhan; Alkin, Esra
This study describes a measurement technique for detecting the power levels of different propagation modes in a circular waveguide in the mod converter structure from a rectangular waveguide to a circular waveguide. Specially designed SMA-waveguide adapters are generally used to measure these power levels of propagating modes inside the circular waveguide. While these adaptors can measure power level of desired transmitted mode they are inadequate to obtain suppression levels of other propagation modes simultaneously. Without need of special adapters the technique proposed in this study can determine the amplitudes of different propagation modes in the waveguide at the same time by using 2-port S-parameter values belonging to two identical mode converters. This method has been verified by a rectangular TE10 - circular TM01 mod converter designed and manufactured at center frequency of about 11.4 GHz.
Citation - WoS: 1
A Numerical Parametric Study of SAR from a Dual-Band PIFA Based Antenna for Mobile Communication
(IEEE, 2017) Serdar Okuyucu; Mustafa Secmen; Korkut Yegin; Basak Ozbakis; Ozbakis, Basak; Secmen, Mustafa; Yegin, Korkut; Ozbakts, Basak; Okuyucu, Serdar
Specific Absorption Rate (SAR) analysis is a vital part of compliance tests for commercial mobile phones performed in accordance with the set of comprehensive standardized practices provided by authoritative bodies. Dependence of SAR on a variety of parameters with the structure of the handset pronounced the most calls for bringing in the SAR analysis of various types of phones into the field of study for reference. This paper focuses on the SAR analysis of a PIFA based mobile phone antenna when operated next to standardized and anatomically correct head models. The effect of averaging method used positioning of the phone frequency of operation and the presence of a homogeneous hand model on SAR is investigated along with the antenna performance in terms of terminal and radiational characteristics.
Citation - WoS: 3
Citation - Scopus: 2
A Parallel Connected Hybrid Microstrip-Substrate Integrated Waveguide Bandstop Filter
(KAUNAS UNIV TECHNOLOGY, 2023) Kemal Guvenli; Sibel Yenikaya; Mustafa Secmen; Guvenli, Kemal; Yenikaya, Sibel; Secmen, Mustafa
This study presents an original parallel connected hybrid microstrip-substrate integrated waveguide (PCHMSIW) bandstop filter. A low-pass filter implemented on a microstrip structure and a SIW-based high-pass filter are connected in parallel to each other. In this way the aim is to obtain a bandstop filter in the novel hybrid design. The parallel connected hybrid microstrip-substrate integrated waveguide (PCHM-SIW) bandstop filter is synthesised simulated and produced. The effects of connecting filters in parallel are discussed. It is seen from the results of CST Studio Suite simulation that PCHM-SIW bandstop filter has a bandwidth of 2.85 GHz and a center frequency of 4.26 GHz. The frequency change rate of the center frequency between simulation and measurement is 7.02 % where it is just 3.76 % for the deviation in bandwidth. The results of the simulation and those of the measurement are close to each other. These results converge to ideal analytical results.
Active impedance calculation in uniform microstrip patch antenna arrays with simulated data
(2012) Mustafa Seçmen; Secmen, Mustafa
This paper presents a simple active impedance evaluation of the antenna elements in uniform microstrip antenna arrays which includes additional impedance contributing from mutual coupling effects. The mutual coupling between antenna elements has been investigated in many studies which utilize from analytical or numerical methods such as method of moments. However these approaches can lead to significant increase in the mathematical complexity for the desired results when the number of elements in the array increases. For this purpose a simple technique for the extraction of active impedances of identical antenna elements in arrays is proposed which uses simulation data of reliable electromagnetic simulation program. In the method initially the self-impedance of an isolated element is evaluated, then this impedance is used initial data in the Newton-iteration approach for the calculation of active impedances of antenna elements in corporate-feed arrays. © 2012 IEEE. © 2012 Elsevier B.V. All rights reserved.
Citation - WoS: 1
Citation - Scopus: 7
An Identification Method Using ESPRIT and PCA for Radar Targets in Resonance Region
(IEEE, 2013) Salih Poyraz; Mustafa Secmen; Poyraz, Salih; Secmen, Mustafa
This paper aims at the development of a fast and sufficiently aspect- independent identification method with the processing of wideband scattered signals from radar targets. In the given method estimation of signal parameters by rotational invariance techniques (ESPRIT) is mainly used for the purpose of classification of targets in resonance region. Multiple reference vectors acquired by using this technique are reduced to one vector for each target with principal component analysis (PCA) and this sole vector is used as feature vector of the given target. The identification phase is employed according to the highest correlation coefficients between ESPRIT vectors of test signals and feature vectors. The proposed method is applied to small-scale airplane targets modeled with wires and about 88 percent identification rate is obtained even for SNR level of -5 dB. The results for other similar dimension reduction techniques are also demonstrated and PCA is found to give better accuracy rates.
Citation - WoS: 4
Citation - Scopus: 3
An RF anechoic box system development for shielding effectiveness measurements
(Institute of Electrical and Electronics Engineers Inc., 2016) Şebnem Seçkin Uǧurlu; Mehmet Can Özgönül; Ahmet Özkurt; Mustafa Seçmen; Ugurlu, Sebnem Seckin; Ozkurt, Ahmet; Secmen, Mustafa; Ozgonul, Mehmet Can
Shielding effectiveness is a term that defines the electromagnetic shielding property of a material. The demand of using wireless technologies and higher frequencies in new devices also bring the need to shield the unwanted electromagnetic fields. Therefore determining the shielding effectiveness of materials becomes an important concept. In this study a compact low-cost RF anechoic box system for shielding effectiveness is explained. The design and construction of the anechoic box is given as well as the designed printed log-periodic antennas specifically for the measurement system that operates in the frequency band of 750-3000 MHz. The simulation and measurement results of the antennas given. Also the performance of the whole system is investigated by measuring the shielding effectiveness of an absorber used in the anechoic box with another reference antenna. Open area measurements are compared to the measurements taken in the anechoic box. © 2016 Elsevier B.V. All rights reserved.
Citation - WoS: 5
Citation - Scopus: 3
Analysis- Design- and Actual Fabrication of a Hybrid Microstrip-SIW Bandpass Filter Based on Cascaded Hardware Integration at X-Band
(KAUNAS UNIV TECHNOLOGY, 2021) Kemal Guvenli; Sibel Yenikaya; Mustafa Secmen; Guvenli, Kemal; Yenikaya, Sibel; Secmen, Mustafa
In this paper the Microstrip-Substrate Integrated Waveguide (M-SIW) bandpass filter is designed simulated and fabricated based on the theoretical analysis. The Substrate Integrated Waveguide (SIW) highpass filter and the microstrip lowpass filter are combined in a hybrid design to achieve the M-SIW bandpass filter in the X-band. This design is more comprehensible and easier to achieve a bandpass filter at a desired frequency. The SIW highpass filter and the microstrip lowpass filter are connected in series to achieve the bandpass filter. To the measured results of the fabricated M-SIW bandpass filter the center frequency is 10.20 GHz and the bandwidth is 2.40 GHz. When the analytical and measurement results are compared the frequency change in the cut-off frequency is 6.02 % and the frequency change in the bandwidth is 8.74 % It is generally seen that analytical simulation and measurement results are compatible with each other. The M-SIW bandpass filter can be broadly used in radar Worldwide Interoperability for Microwave Access (WiMAX) and satellite technologies. The filters are simulated in Computer Simulation Technology (CST) Studio Suite.
Application of dielectric resonator based metamaterial in waveguide coupler
(Institute of Electrical and Electronics Engineers Inc., 2016) Gizem Kalender; Emine Yeşim Zoral; Mustafa Seçmen; Zoral, E. Yesim; Secmen, Mustafa; Kalender, Gizem
In this study an implementation of the metamaterial structure is used in a waveguide directional coupler. For this purpose a four-hole waveguide directional coupler in X-band is designed. Then the block of dielectric-resonator array is inserted between isolation port and holes of the coupler and the performances of the coupler with and without dielectric resonators are compared in terms of the coupling and isolation. The obtained results show that the coupler with dielectric resonators significantly improves the coupling and isolation performances at a new operation frequency band at which the traditional coupler does not work. Therefore the metamaterial structure attains multi-band characteristics to the coupler. Besides this new frequency band can be shifted by arranging the distance between the dielectric resonators and holes. Finally it is also observed that the bandwidth of the new frequency band can be increased by using more dielectric resonators in the array. © 2017 Elsevier B.V. All rights reserved.
A Bandwidth Enhanced Circularly Polarized and Omnidirectional Circular Waveguide Antenna for Satellite Telemetry/Telecommand Systems
(2022) Secmen, Mustafa; Türkmen, Ceyhan; Alkın, Esra
In satellite systems, throughout time interval from launching to settlement on proper orbit and possible significant change in aspect angle of the satellite after the settlement on the orbit, it is required continuous communication between satellite and ground station for current position and other information belonging to satellite. However, position and aspect angle of the satellite with respect to earth will be random due to possible jolts, especially while passing through atmosphere. For this reason, telemetry/TM (transmitter) and telecommand/TC (receiver) antennas on satellite platforms should receive electromagnetic waves from all directions and they should send enough electromagnetic waves to all directions to ensure continuous two-way communication, which is called as telemetry/telecommand. The other fundamental problem on signal levels of communication is polarization mismatch, which is caused by variable aspect angle due to satellite jolts/vibrations. The antennas in earth station and telemetry/telecommunication antennas on satellite are generally selected with same circular polarization to reduce these losses as much as possible. Waveguide antennas, which are omnidirectional or hemispherical and having circular polarization, are frequently used as a solution to this problem. However, considering pattern characteristics of radiation in 3-dimensional space, this antenna gives desired performance to cover about half of entire space (at most 60%). For this reason, to cover entire space as radiation pattern, these antennas are located being far away from each other as much as possible, and signals on these two antennas must be connected via very long waveguides in satellite. Also, these antennas work at only telemetry or telecommand frequencies. Therefore, it is needed to use a total of 4 antennas for coverage of overall space as a radiation pattern, when it is considered as telemetry/telecommand (transceiver). In this project, communication, which is ensured by using systems with 4 antennas in literature and real-life applications, is realized with only a waveguide system having circular polarization. It is the first time a circularly polarized transceiver structure fed by one waveguide structure is developed, which operates in both TM (transmitting) and TC (receiving) frequencies. In addition, another important feature developed in this project is the fact that coverage of 3-dimensional space by using 2 antennas placed on satellite being away from each other is provided with only one antenna system. Overall system/antenna in the project has 3 main sections/designs. First of these sections/designs is rectangular TE10 to circular TM01 waveguide mode converter, which provides feeding slotted antenna arrays on circular waveguide with symmetric mode TM01. In literature, there are waveguide mode converters operating at either TM or TC frequencies, a dual-band converter functioning at TX/RX frequencies is designed for the first time in this project. Second part consists of a power divider/combiner design, which connects mode converter and two circular slotted waveguide antennas perpendicular to each other. Third part is the structure of omnidirectional and bi-directional waveguide antennas, which work at TM and TC frequencies, and contain thick inclined slots to increase the frequency band. As for radiation pattern, most of the entire space is covered with circularly polarized by placing omnidirectional and bi-directional antennas in this section perpendicular to each other and putting disks radially away from circular waveguides. The whole system structure/antenna developed and produced for Ku band gives a return loss of about 10 dB within frequency bands of approximately 500 MHz around 11.75 GHz and 13.75 GHz transmitter and receiver center frequencies, respectively, and the measurements revealed minimum gain of -10 dBi and maximum axial ratio of 4-4.5 dB within the average coverage percentage of 65%.
Citation - WoS: 4
Citation - Scopus: 4
Base station antenna with enhanced cross polarization discrimination performance by using horizontal meandered dipoles and vertical parasitic elements
(Advanced Electromagnetics, 2019) Orhan Murat Kadagan; Ceyhan Türkmen; Mustafa Seçmen; Kadagan, Orhan Murat; Secmen, Mustafa; Turkmen, Ceyhan
In this study the design and implementation of a ±45° dual polarized base station antenna with improved cross-polarization discrimination (XPD) values are presented. In order to increase the cross polarization parasitic elements are added to antenna design which are formed by two orthogonal dipoles above ground plane. The overall antenna and radiator sizes are diminished by using meandered dipoles. The designed compact antenna has VSWR of 2:1 within 1.71-2.69 GHz frequency band which covers GSM 1800/3G/LTE bands. In the given bandwidth minimum gain of the designed antenna is 0 dBi within the beamwidth of 120° (± 60°) at azimuth plane (ϕ = 0°). Minimum XPD value of 2 dB is achieved between 1.71-2.4 GHz for ±60° beamwidth without parasitic elements where XPD values are improved to minimum 10 dB by using thick parasitic elements. The designed antenna is manufactured where return losses for both port 1 and port 2 are measured to be higher than 10 dB and the isolation between ports is more than 20 dB. In addition the measured peak gain values are varied between 3 dB and 7 dB in frequency range of 1.71 GHz-2.69 GHz. XPD values are measured better than almost 10 dB in the given frequency band. © 2021 Elsevier B.V. All rights reserved.
Citation - Scopus: 5
Broadband Compact Quasi Yagi Antenna for UHF Wireless Communication Systems with Enhanced Performance at UHF ISM Bands
(SPOLECNOST PRO RADIOELEKTRONICKE INZENYRSTVI, 2020) Yigit Bakirli; Ali Selek; Mustafa Secmen; Selek, Ali; Secmen, Mustafa; Bakirli, Yigit
In this study a broadband planar quasi Yagi antenna operated at ultra-high frequency (UHF) band is presented. The performance of the antenna is particularly improved for two popular UHF frequencies of 433 and 868 MHz used in several wireless communication applications such as Long Range (LoRa) Internet of Things (IoT) Machine-to-Machine (M2M) Wireless Meter bus (M-bus) and Radio Frequency Identification (RFID). The proposed antenna includes a printed feed dipole with a ground reflector and two parasitic (director) elements on a substrate to keep total dimensions of the antenna within compact size. The parasitic elements are very thick and closely spaced to feed dipole. Significant increase in the bandwidth is obtained with the improved effects due to usage of tapered feed line and tapered reflector. The antenna's 10-dB return loss bandwidth is measured more than 70% between 428 MHz and 896 MHz. The antenna offers moderate peak gain values of 5.5 dBi and 5 dBi, and front-to-back ratio (F/B) values of 12 dB and 14 dB at lower and higher parts of UHF band around 433 and 868 MHz respectively. The peak gain and F/B ratio values are found to be minimum 4 dBi and 8.5 dB within the operating bandwidth respectively.
Citation - WoS: 2
Citation - Scopus: 11
Circularly polarized hemispherical antennas for telemetry and telecommand applications in satellite communication
(Institute of Electrical and Electronics Engineers Inc., 2016) Ceyhan Türkmen; Mustafa Seçmen; Secmen, Mustafa; Turkmen, Ceyhan
This study describes about Ku-band antennas with circular polarization in hemispherical radiation pattern for telemetry and telecommand applications of satellite communication. The first section of antenna contains a septum polarizer structure which converts linear-polarization to circular-polarizations (left-hand and right-hand). This structure feeds a circular aperture waveguide which is the second part. The axial ratio performance of the antenna is improved by adding some metallic rings with optimized dimensions. Therefore circular polarization is achieved in wider azimuth and elevation angles. Two different designs are carried out for 11.35-11.8 GHz and 14.3-14.65 GHz. The return losses are greater than 15 dB in the given frequency bands. Besides the axial ratio of the antenna is under 3 dB throughout 170° at azimuth and elevation which proves circular polarization property in hemispherical region. The gain at the broadside is almost 9.3 dB and it is higher than -10 dB throughout 170° angle coverage. © 2017 Elsevier B.V. All rights reserved.
Citation - WoS: 1
Compact dual-band rectangular TE10 mode to circular TM01 mode converter for telemetry/telecommand applications in satellite communication: design equivalent circuit modeling mode level measurement technique and 3d printed manufacturing
(Tubitak Scientific & Technological Research Council Turkey, 2022) Esra Alkin; Ceyhan Turkmen; Mustafa Secmen; Secmen, Mustafa; Turkmen, Ceyhan; Alkin, Esra
In this study the design of a dual-band mode converter which provides transition from rectangular waveguide TE10 mode to circular waveguide TM01 mode and operates simultaneously in telemetry/telecommand (TT&C) frequencies is presented along with its equivalent circuit and a mode level measurement technique. This dual-band converter is designed to uniformly excite TT&C slot antennas used in satellite communication with symmetric circular TM01 mode. The structure can work as a transceiver due to having one common rectangular waveguide feed. As a Ku-band application a converter giving high purity TM01 mode at circular waveguide at 11.75 GHz/TX and 13.75 GHz/RX center frequencies is designed and manufactured with 3D printing technology. Approximate equivalent circuit models of the designed structure are extracted by using lumped elements from simulated S-parameter results. In addition a measurement technique to detect the normalized power levels of different propagation modes in dual-band mode converter is applied on the manufactured structures to obtain transmission levels of circular TM01 mode and suppression levels of circular TE11 mode. It is revealed from the measurement results that while the designed structure gives more than 17.5 dB return loss and suppression of TE11 mode and less than 0.6 dB insertion loss of TM01 mode within 500 MHz bandwidth at TX band it gives more than 23 dB return loss and suppression of TE11 mode and less than 0.3 dB insertion loss of TM01 mode within 900 MHz bandwidth at RX band.
Citation - Scopus: 1
Compact dual-band rectangular TE10 mode to circular TM01 mode converter for telemetry/telecommand applications in satellite communication: design equivalent circuit modeling mode level measurement technique and 3d printed manufacturing
(Turkiye Klinikleri, 2022) Esra Alkın; Ceyhan Türkmen; Mustafa Seçmen; Secmen, Mustafa; Türkmen, Ceyhan; Alkın, Esra
In this study the design of a dual-band mode converter which provides transition from rectangular waveguide TE10 mode to circular waveguide TM01 mode and operates simultaneously in telemetry/telecommand (TT&C) frequencies is presented along with its equivalent circuit and a mode level measurement technique. This dual-band converter is designed to uniformly excite TT&C slot antennas used in satellite communication with symmetric circular TM01 mode. The structure can work as a transceiver due to having one common rectangular waveguide feed. As a Ku-band application a converter giving high purity TM01 mode at circular waveguide at 11.75 GHz/TX and 13.75 GHz/RX center frequencies is designed and manufactured with 3D printing technology. Approximate equivalent circuit models of the designed structure are extracted by using lumped elements from simulated S-parameter results. In addition a measurement technique to detect the normalized power levels of different propagation modes in dual-band mode converter is applied on the manufactured structures to obtain transmission levels of circular TM01 mode and suppression levels of circular TE11 mode. It is revealed from the measurement results that while the designed structure gives more than 17.5 dB return loss and suppression of TE11 mode and less than 0.6 dB insertion loss of TM01 mode within 500 MHz bandwidth at TX band it gives more than 23 dB return loss and suppression of TE11 mode and less than 0.3 dB insertion loss of TM01 mode within 900 MHz bandwidth at RX band. © 2023 Elsevier B.V. All rights reserved.
Citation - WoS: 6
Citation - Scopus: 7
Compact Planar Folded Monopole Antenna with Coupling Mechanism for Quad ISM Band GNSS and UMTS Applications
(IEEE, 2018) Ali Selek; Ceyhan Turkmen; Mustafa Secmen; Selek, Ali; Secmen, Mustafa; Turkmen, Ceyhan
This study presents a compact meandered type monopole antenna improved with coupling mechanisms to increase the number of allocated frequency bands in consideration. The proposed antenna includes a meandered (folded) conductor structure. Two straight conductors placed at the end of the meandered part bring Industrial Scientific and Medical (ISM) bands at the upper UHF band with coupling mechanism and one stub-like conductor inserted at the input of the meandered region gives another ISM band at the higher frequency. The antenna works at four popular ISM frequency bands of 433 866 915 MHz and 2.4 GHz which cover several wireless applications such as M-bus M2M IoT LoRa RFID Wi-Fi and Bluetooth. Along with the optimized dimensions of meandered and straight conductor parts the proper arrangement of the dimensions related with coplanar feed part additionally provides upper Global Navigation Satellite System (GNSS) band which includes upper bands of GPS GLONASS Galileo applications and almost full coverage of 3G/UMTS-2100/IMT-2000 band. The described antenna has compact structure with about 0.125 lambda(0) by 0.046 lambda(0) at the lowest frequency reasonable gain and omnidirectional radiation pattern characteristics.
Citation - Scopus: 2
Compact Printed Log Periodic Dipole Antenna with Second Order Semi-Circle Iteration
(IEEE, 2017) Mehmet C. Ozgonul; Mustafa Secmen; Serdar Okuyucu; Secmen, Mustafa; Ozgonul, Mehmet C.; Okuyucu, Serdar
In this study a size-reduced Log Periodic Dipole Antenna (LPDA) with second order semi-circle iteration is presented. Second order semi-circles are added to the dipole arms which results in lateral size reduction of 23% and 8% with respect to standard LPDA and LPDA with first order semi-circle iteration respectively. Measurement and simulation results demonstrate that the antenna has a wide range of operating frequency from 0.87 GHz to 2.55 GHz and shows better gain variation than reference LPDAs.
Citation - WoS: 7
Citation - Scopus: 8
Compact wideband tapered-fed printed bow-tie antenna with rectangular edge extension
(WILEY, 2019) Goksenin Bozdag; Mustafa Secmen; Secmen, Mustafa; Bozdag, Goksenin
In this article a wideband printed bow-tie antenna is designed entire band of GPS (L5) PCS IMT-2000 Bluetooth Wi-Fi WiMAX bands and the most of frequency range of UWB. Apart from the traditional designs the proposed antenna includes tapered printed line with a feeding point patch and triangular bows with rectangular edge extensions which makes the antenna more compact. The antenna realized at the frequency band of 1.49-9.5 GHz (more than 6.3:1 ratio bandwidth) has the dimensions of 122mmx56mm (0.61(0)x0.28(0)). According to measurement results the realized gain varies between almost 1 and 6.5 dBi with 4.44dBi average which are in good agreement with simulation results. Radiation patterns at the lower frequencies of operating band show dipole like radiation pattern with higher cross-pol discrimination levels while they degrade at the higher frequencies due to increase in gain.