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 ◽  
...  

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.

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.


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.


A printed dual broadband monopole antenna has been presented here for WLAN and WIMAX applications. The antenna is designed with the help of simulation software HFSS and proposed antenna is fabricated to verify the simulated results with the measured results. The patch of the proposed antenna consists of two identical metallic structures which are like English letter “E” and are placed face to face to each other. Now, the lower arms of E-shaped structures are connected together with a rectangular microstrip transmission line of length 15 mm and width 3.06 mm to form the proposed patch. The proposed “E” shape patch is printed on FR4 substrate of height 1.6 mm, relative permittivity εr= 4.4, and loss tangent 0.02. The ground plane of the proposed antenna consists of partial rectangular metal at opposite side of the patch. The proposed antenna achieves dual band characteristics using the proposed structure. The measured results show that the proposed structure covers the transmission bands from 2.45 GHz to 3.66 GHz with center frequency of 3.0 GHz and from 4.16 GHz to 5.94 GHz with center frequency of 5.37 GHz. There is a good impedance matching between measurement result and computer simulated results. The measured percentage bandwidths have been obtained by 39.1 % and 35.24 %, respectively. The peak gain (measured) at 3 GHz and 5.37 GHz resonant frequencies are 3 dBi and 4 dBi, respectively. This proposed antenna also exhibits with monopole like E-Plane and H-plane co-polarization radiation pattern at two center frequencies. The obtained bands are useful for WLAN and WiMAX applications.


Author(s):  
Muhammad Mateen Hassan ◽  
Muzhair Hussain ◽  
Adnan Ahmed Khan ◽  
Imran Rashid ◽  
Farooq Ahmed Bhatti

Abstract The paper presents a 1 × 2 B-shaped antenna array for dual-band operation at 4 and 8 GHz. The antenna design consists of a rectangular patch with two annular-strip lines fabricated on the top layer and finite ground plane on the bottom layer. The array is formed by designing an optimum T-shaped microstrip line for impedance matching. The dimensions of the antenna array are 78 × 36 × 1.6 mm3. Full-wave simulations have been conducted and the measured results are in good consent with the simulated results. The measured impedance bandwidth (reference −10 dB) has been observed at 3.84–4.16 and 7.78–8.38 GHz. Measured peak gain and radiation efficiency at 4 and 8 GHz are 8.3, 9.4 dB and 82.5 and 81.2%, respectively.


Frequenz ◽  
2019 ◽  
Vol 73 (1-2) ◽  
pp. 25-36
Author(s):  
Kahina Djafri ◽  
Mouloud Challal ◽  
Jordi Romeu

Abstract This paper presents a novel design approach of a compact dual-band monopole antenna with an overall size of 18.9x13x1.6mm3. The proposed antenna is composed of a fractal ring shaped patch fed by a Y-shaped transmission line on the top side of the substrate and a second fractal ring along with a U-shaped ground plane on the bottom side. The second fractal ring, identical to the radiating ring, is loaded and a rectangular slot is etched at the top side of the ground plane respectively, to achieve dual-band characteristic and improve the impedance matching. The effect of standard ground-plane (SGP) of a laptop computer is incorporated in the design; the antenna is mounted on a SGP in order to investigate its performance. The antenna covers widely the frequency bands of the WLAN 2.4 GHz (2.2–2.52 GHz) and WiMAX 3.5 GHz (3.32–4.35 GHz), and exhibits an omnidirectional radiation pattern in the H-plane and a monopole like radiation pattern in the E-plane. A good agreement between the simulated and measured results indicates that the proposed dual-band antenna design is suitable for WLAN/WiMAX applications.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
M. R. Ahsan ◽  
M. T. Islam ◽  
M. Habib Ullah ◽  
N. Misran

A meandered-microstrip fed circular shaped monopole antenna loaded with vertical slots on a high dielectric material substrate(εr=15)is proposed in this paper. The performance criteria of the proposed antenna have been experimentally verified by fabricating a printed prototype. The experimental results show that the proposed antenna has achieved wider bandwidth with satisfactory gain by introducing meandered-microstrip feeding in assistant of partial ground plane. It is observed that, the −10 dB impedance bandwidth of the proposed antenna at lower band is 44.4% (600 MHz–1 GHz) and at upper band is 28% (2.25 GHz–2.95 GHz). The measured maximum gains of −1.18 dBi and 4.87 dBi with maximum radiation efficiencies have been observed at lower band and upper band, respectively. The antenna configuration and parametric study have been carried out with the help of commercially available computer-aided EM simulator, and a good accordance is perceived in between the simulated and measured results. The analysis of performance criteria and almost consistent radiation pattern make the proposed antenna a suitable candidate for UHF RFID, WiMAX, and WLAN applications.


2015 ◽  
Vol 8 (8) ◽  
pp. 1197-1206 ◽  
Author(s):  
Seyed Saeed Mirmosaei ◽  
Seyed Ebrahim Afjei ◽  
Esfandiar Mehrshahi ◽  
Mohammad M. Fakharian

In this paper, an ultra-wideband (UWB) planar monopole antenna with impedance bandwidth from 2.83 to 11.56 GHz and dual band-notched characteristics is presented. The antenna consists of a small rectangular ground plane, a bat-shaped radiating patch, anda 50-Ω microstrip line. The notched bands are realized by introducing two different types of structures. The half-wavelength spiral-slots are etched on the radiating patch to obtain a notched band in 5.15 5.925 GHz for WLAN, HIPERLAN, and DSRC systems. Based on the single band-notched UWB antenna, the second notched band is realized by etching a folded stepped impedance resonator as defected ground structure on the ground plane for WiMAX and C-band communication systems. The notched frequencies can be adjusted by altering the length of resonant cells. Surface current distributions and equivalent circuit are used to illustrate the notched mechanism. The performance of this antenna both by simulation and by experiment indicates that the proposed antenna is suitable and a good candidate for UWB applications.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Wang-Sang Lee ◽  
Hyun-Sung Tae ◽  
Kyoung-Sub Oh ◽  
Jong-Won Yu

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.


Author(s):  
A H Majeed ◽  
K H Sayidmarie

<p class="Default">In this paper, a new approach to the design of an UWB monopole antenna with dual band-notched characteristics is presented.   The antenna has the form of an elliptical monopole over a ground plane having an elliptical slot to achieve the UWB. The dual-band notch function is created by inserting a U-shaped and a C-shaped slots on the radiating patch, thus no extra size is needed. The proposed antenna shows a good omnidirectional radiation pattern across the band from 3.2 to more than 14 GHz. The dual band-rejection is for 4.88-5.79GHz centered at 5.4GHz and 7.21-8.46 GHz centered at 7.8 GHz. The antenna prototype using the FR-4 substrate with ε<sub>r</sub>=4.3 has a compact size of 25mm×25 mm ×1.45mm. The fabricated prototype showed experimental results comparable to those obtained from the simulations.</p>


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