scholarly journals Genetic Algorithms in Antennas and Smart Antennas Design Overview: Two Novel Antenna Systems for Triband GNSS Applications and a Circular Switched Parasitic Array for WiMax Applications Developments with the Use of Genetic Algorithms

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Stylianos C. Panagiotou ◽  
Stelios C. A. Thomopoulos ◽  
Christos N. Capsalis

Genetic algorithms belong to a stochastic class of evolutionary techniques, whose robustness and global search of the solutions space have made them extremely popular among researchers. They have been successfully applied to electromagnetic optimization, including antenna design as well as smart antennas design. In this paper, extensive reference to literature related antenna design efforts employing genetic algorithms is taking place and subsequently, three novel antenna systems are designed in order to provide realistic implementations of a genetic algorithm. Two novel antenna systems are presented to cover the new GPS/Galileo band, namely, L5 (1176 MHz), together with the L1 GPS/Galileo and L2 GPS bands (1575 and 1227 MHz). The first system is a modified PIFA and the second one is a helical antenna above a ground plane. Both systems exhibit enhanced performance characteristics, such as sufficient front gain, input impedance matching, and increased front-to-back ratio. The last antenna system is a five-element switched parasitic array with a directional beam with sufficient beamwidth to a predetermined direction and an adequate impedance bandwidth which can be used as receiver for WiMax signals.

2018 ◽  
Vol 10 (3) ◽  
pp. 336-344 ◽  
Author(s):  
Rajarshi Sanyal ◽  
Partha Pratim Sarkar ◽  
Santosh Kumar Chowdhury

This article presents a compact novel quasi-self-complementary semi-octagonal-shaped antenna for ultra-wideband (UWB) application. The proposed novel structure is fed by a microstrip line where different rectangular truncation is etched to the ground plane as an impedance matching element, which results for much wider impedance bandwidth (VSWR<2) from 2.9 to 20 GHz. In order to obtain band-notched characteristics at 5.5 GHz, an open-ended, quarter wavelength, spiral-shaped stub is introduced in the vicinity of the truncated part of the ground plane. An equivalent circuit model is adopted to investigate the band rejection characteristics of the ground plane stub. Sharpness of the rejection band can be controlled by maintaining the gap between stub resonator and the slotted periphery of ground plane. The proposed antenna design is validated by experimental measurements.


Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 651-655 ◽  
Author(s):  
Yilin Liu ◽  
Kama Huang

Abstract A novel design of a coplanar waveguide (CPW) feed antenna array with circular polarization (CP) and a high front-to-back ratio is described. The proposed CP array is achieved by using a compact CPW–slotline transition network etched in the ground plane. The measured results show that this kind of feeding method can improve the impedance bandwidth, as well as the axial ratio bandwidth of the CP antenna array and provide adequate gain. The proposed array can achieve a 6.08% impedance bandwidth and a 4.10% CP bandwidth. Details of the antenna design and experimental results are presented and discussed.


2014 ◽  
Vol 8 (1) ◽  
pp. 117-124 ◽  
Author(s):  
Mohammed Younus Talha ◽  
Kamili Jagadeesh Babu ◽  
Rabah W. Aldhaheri

A novel compact multiple-input–multiple-output (MIMO) antenna system operating from 5 to 7.3 GHz is proposed for wireless applications. It comprises of two similar antennas with microstrip feeding and radiating patches developed on a reduced ground plane. The developed antenna system resonates at a dual-band of 5.4 and 6.8 GHz frequencies, giving an impedance bandwidth of 38% (based on S11 < −10 dB). The unique structure of the proposed MIMO system gives a reduced mutual coupling of −27 dB at 5.4 GHz resonant frequency and −19 dB at 6.8 GHz resonant frequency and in the entire operating band the coupling is maintained well below −16 dB. The envelope correlation coefficient of the proposed MIMO system is calculated and is found to be less than 0.05 in the operating band. The measured and simulation results are found in good agreement.


2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Chien-Jen Wang ◽  
Dai-Heng Hsieh

A small dual-band monopole antenna with coplanar waveguide (CPW) feeding structure is presented in this paper. The antenna is composed of a meandered monopole, an extended conductor tail, and an asymmetrical ground plane. Tuning geometrical structure of the ground plane excites an additional resonant frequency band and thus enhances the impedance bandwidth of the meandered monopole antenna. Unlike the conventional monopole antenna, the new resonant mode is excited by a slot trace of the CPW transmission line. The radiation performance of the slot mode is as similar as that of the monopole. The parametrical effect of the size of the one-side ground plane on impedance matching condition has been derived by the simulation. The measured impedance bandwidths, which are defined by the reflection coefficient of −6 dB, are 186 MHz (863–1049 MHz, 19.4%) at the lower resonant band and 1320 MHz (1490–2810 MHz, 61.3%) at the upper band. From the results of the reflection coefficients of the proposed monopole antenna, the operated bandwidths of the commercial wireless communication systems, such as GSM 900, DCS, IMT-2000, UMTS, WLAN, LTE 2300, and LTE 2500, are covered for uses.


A wideband coplanar waveguide (CPW) antenna with circular polarization characteristics using modified ground slot is studied in this work. Proposed design incorporates a hexagonal slot instead of rectangular slot, accounting for enhanced impedance matching. This ground slot is energized by a 50Ω feed line, resulting in excitation of two orthogonal phase quadrature modes (even-odd modes). Thus, fulfilling the essential criteria required for realizing circular polarization. A narrow horizontal slit (lg) is embedded in the ground plane at immediate left of feed line, accounting for wideband characteristics. 10dB impedance bandwidth of proposed antenna extends from 2.65- 5.60 GHz, while 3dB axial ratio bandwidth extends from 3.90- 5.80 GHz. Hence, overlapping bandwidth of proposed antenna extends from 3.90 - 5.60 GHz. RHCP characteristics with monopole radiation pattern makes proposed antenna useful for WLAN, radio navigation and radiolocation applications.


2020 ◽  
Vol 8 (5) ◽  
pp. 3988-3990

In this paper, A coplanar waveguide (CPW) ultra-wideband(UWB) antenna is designed, analyzed and simulated by computer simulation technology(CST). The proposed antenna is fabricated on FR-4 dielectric substrate. A microstrip feed line is used to excite the antenna.The ground plane is slotted to improve the impedance bandwidth (BW). Here, a rectangular patch is used as radiator and two corners out of four are truncated to improve impedance matching and UWB characterization.This antenna satisfies UWB characteristics like VSWR<2, Return loss(S11)<-10 dB,Gain<5dB and the antenna is operating within the frequency range of 1.59 to 11.87 GHz range which covers whole ultra wideband i.e. 3.1 to 10.6 GHz range.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Akrem Asmeida ◽  
Zuhairiah Zainal Abidin ◽  
Shaharil Mohd Shah ◽  
Muhammad Ramlee Kamarudin ◽  
Norun Abdul Malek ◽  
...  

Producing a suitable impedance matching between the radiating element and the feedline is the prior hurdle to overcome for a wideband antenna with circular polarisation designs. This study presents a novel antenna consisting of a defected ground structure (DGS) and a crescent-slot radiating patch for broad impedance bandwidth. In addition, a narrow rectangular slot was etched on the ground plane for antenna compactness and outcomes improvement. In order to examine the reliability, two different numerical softwares were compared based on the antenna’s basic structure. Apart from this, an equivalent circuit of the proposed prototype is modelled logically using ADS 2016. The numerical results demonstrate that the impedance bandwidth was about 74.6% for < −10 dB, while the 3 dB axial ratio bandwidth greater than 53% was achieved. In the operational bandwidth of the design, good impedance matching and high efficiency were seen, which shows that this design is appropriate for modern wireless communication systems in ISM and GSM bands.


2021 ◽  
Author(s):  
Saida Ibnyaich ◽  
Samira Chabaa ◽  
Layla wakrim ◽  
Abdessalam El Yassini ◽  
Abdelouhab Zeroual ◽  
...  

Abstract A new compact pentagonal microstrip patch antenna with slotted ground plane structure, developed for use in ultrawideband applications, is studied in this article. The proposed antenna is mainly constituted by a pentagonal shaped patch antenna, a defected ground plane structure, two stubs, and four slots to improve the bandwidth. The designed antenna has an overall dimension of 30×17.59×1.6mm 3 , for WIMAX /WLAN/ WiFi/HIPERLAN-2 /Bluetooth /LTE /5G applications with a very large bandwidth starting from 2.66 GHz to 10.82 GHz (S 11 <-6 dB ). A parametric study of the ground plane structure was carried out to find the final and the optimal UWB antenna, and to confirm that the antenna has good performance and broader bandwidth. The proposed antenna prototype has been fabricated. The measured results indicate that the antenna has a good impedance matching. The antenna has an electrically small dimension with a good gain, a notable efficiency, and a wide impedance bandwidth, which makes this antenna an excellent candidate for ultrawideband wireless communication, microwave imaging, radar applications, and the major part of the mobile phone frequencies as well.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
A. Mchbal ◽  
N. Amar Touhami ◽  
H. Elftouh ◽  
A. Dkiouak

A compact ultra-wideband (UWB) multiple input-multiple output (MIMO) antenna with high isolation is designed for UWB applications. The proposed MIMO antenna consists of two identical monopole antenna elements. To enhance the impedance matching, three slots are formed on the ground plane. The arc structure as well as the semicircle with an open-end slot is employed on the radiating elements the fact which helps to extend the impedance bandwidth of the monopole antenna from 3.1 up to 10.6 GHz, which corresponds to the UWB band. A ground branch decoupling structure is introduced between the two elements to reduce the mutual coupling. Simulation and measurement results show a bandwidth range from 3.1 to 11.12 GHz with |S11_|<−15 dB, |S21_|<−20 dB, and ECC < 0.002.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Rahul Yadav

This paper presents a spiral antenna design operating in the frequency range of 1–15 GHz having both selective notch bands and wideband response. The main feed arm of spiral antenna is configured as rectangular monopole of width quarter wavelength to achieve impedance matching with standard 50 Ω excitation. Frequency tuning in the design is achieved by placing varactor diode at an appropriate position along the spiral arms and in the ground plane. The design offers a peak gain of 3.4 dB (simulated) and 3 dB (measured). The unique frequency response of antenna makes its suitable to be used for front-end system of cognitive radio for sensing the spectrum in various modes.


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