scholarly journals A Balanced-Fed Dual Inverted-F Antenna with Reduced Human Body Effects

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Wang-Sang Lee ◽  
Hyun-Sung Tae ◽  
Kyoung-Sub Oh ◽  
Jong-Won Yu
Keyword(s):  
Resonant Frequency ◽  
Human Body ◽  
Impedance Matching ◽  
Ground Plane ◽  
Impedance Bandwidth ◽  
Compact Structure ◽  
Close Proximity

A balanced-fed dual inverted-F antenna with reduced human body effects for WLAN applications at 2.45 GHz is presented. In order to reduce the influence by a close proximity or a touch of a human body, the proposed antenna employs an impedance matching using a lumped LC-balun which has the simple and compact structure applying for mobile handsets. The resonant frequency of the proposed antenna is fixed at 2.45 GHz regardless of the close proximity of a human body. By applying for the L-shape ground plane, the proposed antenna has the wide impedance bandwidth of about 150 MHz and the peak realized gain of about 4 dBi.

scholarly journals Planar MIMO Antenna with Slits for WBAN Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Do-Gu Kang ◽  
Jinpil Tak ◽  
Jaehoon Choi
Keyword(s):  
Resonant Frequency ◽  
Human Body ◽  
Impedance Matching ◽  
Ground Plane ◽  
Antenna Size ◽  
Mimo Antenna ◽  
Ism Band ◽  
Antenna Performance

A planar MIMO antenna with slits for WBAN applications is proposed. The antenna consists of two PIFAs, ground pads, and two slits. By adding ground pads, the antenna size is reduced with improved impedance matching. Through two slits in a ground plane, the isolation characteristic is improved and the resonant frequency can be controlled. To analyze the antenna performance on a human body, the proposed antenna on a human equivalent flat phantom is investigated through simulations. Regardless of the existence of the phantom, the antenna operates in 2.4 GHz ISM band with the isolation higher than 18 dB.

scholarly journals Design and Evaluation of a Flexible Dual-Band Meander Line Monopole Antenna for On- and Off-Body Healthcare Applications

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 475
Author(s):  
Shahid M Ali ◽  
Cheab Sovuthy ◽  
Sima Noghanian ◽  
Zulfiqur Ali ◽  
Qammer H. Abbasi ◽  
...  
Keyword(s):  
Human Body ◽  
Impedance Matching ◽  
Ground Plane ◽  
Monopole Antenna ◽  
Dual Band ◽  
Impedance Bandwidth ◽  
Healthcare Applications ◽  
Wearable Antennas ◽  
Challenging Environment ◽  
Meander Line

The human body is an extremely challenging environment for wearable antennas due to the complex antenna-body coupling effects. In this article, a compact flexible dual-band planar meander line monopole antenna (MMA) with a truncated ground plane made of multiple layers of standard off-the-shelf materials is evaluated to validate its performance when worn by different subjects to help the designers who are shaping future complex on-/off-body wireless devices. The antenna was fabricated, and the measured results agreed well with those from the simulations. As a reference, in free-space, the antenna provided omnidirectional radiation patterns (ORP), with a wide impedance bandwidth of 1282.4 (450.5) MHz with a maximum gain of 3.03 dBi (4.85 dBi) in the lower (upper) bands. The impedance bandwidth could reach up to 688.9 MHz (500.9 MHz) and 1261.7 MHz (524.2 MHz) with the gain of 3.80 dBi (4.67 dBi) and 3.00 dBi (4.55 dBi), respectively, on the human chest and arm. The stability in results shows that this flexible antenna is sufficiently robust against the variations introduced by the human body. A maximum measured shift of 0.5 and 100 MHz in the wide impedance matching and resonance frequency was observed in both bands, respectively, while an optimal gap between the antenna and human body was maintained. This stability of the working frequency provides robustness against various conditions including bending, movement, and relatively large fabrication tolerances.

scholarly journals Compact and Low-Profile UWB Antenna Based on Graphene-Assembled Films for Wearable Applications

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2552 ◽  
Author(s):  
Ran Fang ◽  
Rongguo Song ◽  
Xin Zhao ◽  
Zhe Wang ◽  
Wei Qian ◽  
...  
Keyword(s):  
Human Body ◽  
Coplanar Waveguide ◽  
Wearable Devices ◽  
Impedance Bandwidth ◽  
Body Measurements ◽  
Uwb Antenna ◽  
Wearable Antennas ◽  
Low Profile ◽  
Close Proximity ◽  
Feeding Structure

In this article, a graphene-assembled film (GAF)-based compact and low-profile ultra-wide bandwidth (UWB) antenna is presented and tested for wearable applications. The highly conductive GAFs (~106 S/m) together with the flexible ceramic substrate ensure the flexibility and robustness of the antenna, which are two main challenges in designing wearable antennas. Two H-shaped slots are introduced on a coplanar-waveguide (CPW) feeding structure to adjust the current distribution and thus improve the antenna bandwidth. The compact GAF antenna with dimensions of 32 × 52 × 0.28 mm3 provides an impedance bandwidth of 60% (4.3–8.0 GHz) in simulation. The UWB characteristics are further confirmed by on-body measurements and show a bending insensitive bandwidth of ~67% (4.1–8.0 GHz), with the maximum gain at 7.45 GHz being 3.9 dBi and 4.1 dBi in its flat state and bent state, respectively. Our results suggest that the proposed antenna functions properly in close proximity to a human body and can sustain repetitive bending, which make it well suited for applications in wearable devices.

Design of a compact MIMO antenna system with reduced mutual coupling

2014 ◽  
Vol 8 (1) ◽  
pp. 117-124 ◽  
Author(s):  
Mohammed Younus Talha ◽  
Kamili Jagadeesh Babu ◽  
Rabah W. Aldhaheri
Keyword(s):  
Resonant Frequency ◽  
Mutual Coupling ◽  
Mimo System ◽  
Ground Plane ◽  
Multiple Input Multiple Output ◽  
Antenna System ◽  
Dual Band ◽  
Impedance Bandwidth ◽  
Mimo Antenna ◽  
Operating Band

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.

scholarly journals Bandwidth Enhancement Technique of the Meandered Monopole Antenna

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Chien-Jen Wang ◽  
Dai-Heng Hsieh
Keyword(s):  
Communication Systems ◽  
Coplanar Waveguide ◽  
Impedance Matching ◽  
Ground Plane ◽  
Matching Condition ◽  
Resonant Mode ◽  
Monopole Antenna ◽  
Dual Band ◽  
Impedance Bandwidth ◽  
Feeding Structure

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.

scholarly journals A Wideband Circular Polarized Antenna using Coplanar Waveguide

2019 ◽  
Vol 8 (6S4) ◽  
pp. 587-589
Keyword(s):  
Circular Polarization ◽  
Coplanar Waveguide ◽  
Impedance Matching ◽  
Ground Plane ◽  
Axial Ratio ◽  
Impedance Bandwidth ◽  
Rectangular Slot ◽  
Feed Line ◽  
Polarization Characteristics ◽  
Orthogonal Phase

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.

scholarly journals Design of Ultra Wideband Antenna

2020 ◽  
Vol 8 (5) ◽  
pp. 3988-3990
Keyword(s):  
Return Loss ◽  
Coplanar Waveguide ◽  
Impedance Matching ◽  
Ground Plane ◽  
Dielectric Substrate ◽  
Ultra Wideband ◽  
Impedance Bandwidth ◽  
Uwb Antenna ◽  
Rectangular Patch ◽  
Microstrip Feed

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.

scholarly journals Wideband Crescent-Shaped Slotted Printed Antenna with Radiant Circular Polarisation

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Akrem Asmeida ◽  
Zuhairiah Zainal Abidin ◽  
Shaharil Mohd Shah ◽  
Muhammad Ramlee Kamarudin ◽  
Norun Abdul Malek ◽  
...  
Keyword(s):  
Communication Systems ◽  
High Efficiency ◽  
Impedance Matching ◽  
Ground Plane ◽  
Axial Ratio ◽  
Basic Structure ◽  
Impedance Bandwidth ◽  
Defected Ground Structure ◽  
Circular Polarisation ◽  
Rectangular Slot

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.

scholarly journals A Pentagonal Shaped Microstrip Planar Antenna with Defected Ground Structure for Ultrawideband Applications

2021 ◽  
Author(s):  
Saida Ibnyaich ◽  
Samira Chabaa ◽  
Layla wakrim ◽  
Abdessalam El Yassini ◽  
Abdelouhab Zeroual ◽  
...  
Keyword(s):  
Patch Antenna ◽  
Impedance Matching ◽  
Ground Plane ◽  
Small Dimension ◽  
Impedance Bandwidth ◽  
Defected Ground Structure ◽  
Uwb Antenna ◽  
Large Bandwidth ◽  
Excellent Candidate ◽  
Radar Applications

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.

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
Keyword(s):  
Genetic Algorithms ◽  
Impedance Matching ◽  
Ground Plane ◽  
Smart Antennas ◽  
Antenna System ◽  
Antenna Design ◽  
Impedance Bandwidth ◽  
Parasitic Array ◽  
Extensive Reference ◽  
Antenna Systems

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.

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