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.

scholarly journals Design of a Substrate-Integrated Fabry-Pérot Cavity Antenna forK-Band Applications

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Truong Khang Nguyen ◽  
Ikmo Park
Keyword(s):  
Coplanar Waveguide ◽  
Ground Plane ◽  
Cost Effective ◽  
Frequency Selective Surface ◽  
High Gain ◽  
Hole Array ◽  
Impedance Bandwidth ◽  
Low Profile ◽  
Fabry Perot ◽  
Feeding Structure

This paper presents the design of a planar, low-profile, high-gain, substrate-integrated Fabry-Pérot cavity antenna forK-band applications. The antenna consists of a frequency selective surface (FSS) and a planar feeding structure, which are both lithographically patterned on a high-permittivity substrate. The FSS is made of a circular hole array that acts as a partially reflecting mirror. The planar feeding structure is a wideband leaky-wave slit dipole fed by a coplanar waveguide whose ground plane acts as a perfect reflective mirror. The measured results show that the proposed antenna has an impedance bandwidth of more than 8% (VSWR ≤ 2), a maximum gain of 13.1 dBi, and a 3 dB gain bandwidth of approximately 1.3% at a resonance frequency of around 21.6 GHz. The proposed antenna features low-profile, easy integration into circuit boards, mechanical robustness, and excellent cost-effective mass production suitability.

Wideband low-profile aperture-coupled circularly polarized antenna based on metasurface

2018 ◽  
Vol 10 (7) ◽  
pp. 851-859 ◽  
Author(s):  
Qi Zheng ◽  
Chenjiang Guo ◽  
Jun Ding
Keyword(s):  
Coplanar Waveguide ◽  
Axial Ratio ◽  
High Gain ◽  
Mode Analysis ◽  
Impedance Bandwidth ◽  
Equivalent Circuit Analysis ◽  
Circularly Polarized ◽  
Low Profile ◽  
Compact Size ◽  
Feeding Structure

AbstractIn this paper, a metasurface-based aperture-coupled circularly polarized (CP) antenna with wideband and high radiation gain is proposed and analyzed. The proposed antenna is comprised of coplanar waveguide coupling with 4 × 4 corner truncated square patches, which show compact size and low profile. The mechanism of the CP antenna is analyzed theoretically based on the mode analysis and equivalent circuit analysis. The parameters of feeding structure and truncated corner are studied and optimized to achieve wide impedance bandwidth (BW) and axial ratio (AR) BW. Finally, an overall size of 38.8 mm × 38.8 mm × 3.5 mm (0.71λ0 × 0.71λ0 × 0.064λ0 at 5.5 GHz) CP antenna is proposed and fabricated. The simulated results demonstrate that over 41.7% impedance BW (S11 < −10 dB) of 4.55–6.95 GHz and 3 dB AR BW of 5.05–6.15 GHz (fractional BW is about 19.6%) are achieved. In addition, the antenna yielded a broadside CP radiation with a high gain average about 7.5 dBic. Experimental results are in good agreement with the simulated ones.

scholarly journals CPW-fed circularly-polarized antenna array with high front-to-back ratio and low-profile

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 651-655 ◽  
Author(s):  
Yilin Liu ◽  
Kama Huang
Keyword(s):  
Antenna Array ◽  
Coplanar Waveguide ◽  
Ground Plane ◽  
Axial Ratio ◽  
Antenna Design ◽  
Impedance Bandwidth ◽  
Feeding Method ◽  
Circularly Polarized ◽  
Low Profile ◽  
Novel Design

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.

scholarly journals Millimeter Wave Fabry-Perot Resonator Antenna Fed by CPW with High Gain and Broadband

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Xue-Xia Yang ◽  
Guan-Nan Tan ◽  
Bing Han ◽  
Hai-Gao Xue
Keyword(s):  
Millimeter Wave ◽  
Coplanar Waveguide ◽  
Dielectric Substrate ◽  
High Gain ◽  
Center Frequency ◽  
Impedance Bandwidth ◽  
Gain Bandwidth ◽  
Broad Bandwidth ◽  
Low Profile ◽  
Fabry Perot

A novel millimeter wave coplanar waveguide (CPW) fed Fabry-Perot (F-P) antenna with high gain, broad bandwidth, and low profile is reported. The partially reflective surface (PRS) and the ground form the F-P resonator cavity, which is filled with the same dielectric substrate. A dual rhombic slot loop on the ground acts as the primary feeding antenna, which is fed by the CPW and has broad bandwidth. In order to improve the antenna gain, metal vias are inserted surrounding the F-P cavity. A CPW-to-microstrip transition is designed to measure the performances of the antenna and extend the applications. The measured impedance bandwidth ofS11less than −10 dB is from 34 to 37.7 GHz (10.5%), and the gain is 15.4 dBi at the center frequency of 35 GHz with a 3 dB gain bandwidth of 7.1%. This performance of the antenna shows a tradeoff among gain, bandwidth, and profile.

scholarly journals Wearable Textile Antennas with High Body-Antenna Isolation: Design, Fabrication, and Characterization Aspects

2020 ◽  
Author(s):  
Nikolay Atanasov ◽  
Gabriela Atanasova ◽  
Blagovest Atanasov
Keyword(s):  
Resonant Frequency ◽  
Human Body ◽  
Detailed Examination ◽  
Electromagnetic Properties ◽  
Trade Off ◽  
High Body ◽  
Wearable Antennas ◽  
Low Profile ◽  
Design Requirements

This chapter provides a brief overview of the types of wearable antennas with high body-antenna isolation. The main parameters and characteristics of wearable antennas and their design requirements are discussed. Next, procedures (passive and active) to test the performance of wearable antennas are presented. The electromagnetic properties of the commercially available textiles used as antenna substrates are investigated and summarized here, followed by a more detailed examination of their effects on the performance of wearable antennas with high body-antenna isolation. A trade-off between substrate electromagnetic properties and resonant frequency, bandwidth, radiation efficiency, and maximum gain is presented. Finally, a case study is presented with detailed analyses and investigations of the low-profile all-textile wearable antennas with high body-antenna isolation and low SAR. Their interaction with a semisolid homogeneous human body phantom is discussed. The simulations and experimental results from different (in free-space and on-body) scenarios are presented.

scholarly journals A Compact Printed Quadruple Band-Notched UWB Antenna

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Xiaoyin Li ◽  
Lianshan Yan ◽  
Wei Pan ◽  
Bin Luo
Keyword(s):  
Coplanar Waveguide ◽  
Radiation Patterns ◽  
Uwb Antenna ◽  
Broad Bandwidth ◽  
Wireless Applications ◽  
Notched Band ◽  
Low Profile ◽  
X Band

A novel compact coplanar waveguide- (CPW-) fed ultrawideband (UWB) printed planar volcano-smoke antenna (PVSA) with four band-notches for various wireless applications is proposed and demonstrated. The low-profile antenna consists of a C-shaped parasitic strip to generate a notched band at 8.01~8.55 GHz for the ITU band, two C-shaped slots, and an inverted U-shaped slot etched in the radiator patch to create three notched bands at 5.15~5.35 GHz, 5.75~5.85 GHz, and 7.25~7.75 GHz for filtering the WLAN and X-band satellite signals. Simulated and measured results both confirm that the proposed antenna has a broad bandwidth of 3.1~12 GHz with VSWR < 2 and good omnidirectional radiation patterns with four notched-bands.

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 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.

Slot loaded EBG-based metasurface for performance improvement of circularly polarized antenna for WiMAX applications

2019 ◽  
Vol 12 (3) ◽  
pp. 212-220 ◽  
Author(s):  
Alka Verma ◽  
Anil Kumar Singh ◽  
Neelam Srivastava ◽  
Shilpee Patil ◽  
Binod Kumar Kanaujia
Keyword(s):  
Performance Improvement ◽  
Coplanar Waveguide ◽  
Axial Ratio ◽  
Impedance Bandwidth ◽  
Compact Structure ◽  
Circularly Polarized ◽  
Feed Line ◽  
Rectangular Patch ◽  
Low Profile ◽  
Good Agreement

AbstractIn this paper, an electromagnetic band gap (EBG) metasurface (MS) superstrate-based circularly polarized antenna for the WiMAX (3.5 GHz) band is proposed. The proposed structure comprises a 2 × 2 slot-loaded rectangular patch MS array that can be perceived as a polarization-dependent EBG MS superstrate. Furthermore, to achieve circular polarization, the proposed antenna has an inclined coupling slot onto the ground with a conventional coplanar waveguide feed line. The proposed antenna has a compact structure with a low profile of 0.037λ0 (λ0 stands for the free-space wavelength at 3.48 GHz) and a ground size of 30 × 30 mm2. The measured results show that the −10 dB impedance bandwidth for the proposed antenna is 34.6% and the 3-dB axial ratio (AR) bandwidth is 6.8% with a peak gain of 3.91 dBi in the desired operating band. Good agreement between the simulated and the measured results verifies the performance of the proposed antenna.

scholarly journals Analysis on the Effects of the Human Body on the Performance of Electro-Textile Antennas for Wearable Monitoring and Tracking Application

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1636 ◽  
Author(s):  
Nurul Huda Abd Rahman ◽  
Yoshihide Yamada ◽  
Muhammad Shakir Amin Nordin
Keyword(s):  
Human Body ◽  
Free Space ◽  
Dielectric Material ◽  
Near Field ◽  
The Body ◽  
Antenna Structure ◽  
Dielectric Characteristics ◽  
Wearable Antennas ◽  
Close Proximity ◽  
Substantial Drop

Previous works have shown that wearable antennas can operate ideally in free space; however, degradation in performance, specifically in terms of frequency shifts and efficiency was observed when an antenna structure was in close proximity to the human body. These issues have been highlighted many times yet, systematic and numerical analysis on how the dielectric characteristics may affect the technical behavior of the antenna has not been discussed in detail. In this paper, a wearable antenna, developed from a new electro-textile material has been designed, and the step-by-step manufacturing process is presented. Through analysis of the frequency detuning effect, the on-body behavior of the antenna is evaluated by focusing on quantifying the changes of its input impedance and near-field distribution caused by the presence of lossy dielectric material. When the antenna is attached to the top of the body fat phantom, there is an increase of 17% in impedance, followed by 19% for the muscle phantom and 20% for the blood phantom. These phenomena correlate with the electric field intensities (V/m) observed closely at the antenna through various layers of mediums (z-axis) and along antenna edges (y-axis), which have shown significant increments of 29.7% in fat, 35.3% in muscle and 36.1% in blood as compared to free space. This scenario has consequently shown that a significant amount of energy is absorbed in the phantoms instead of radiated to the air which has caused a substantial drop in efficiency and gain. Performance verification is also demonstrated by using a fabricated human muscle phantom, with a dielectric constant of 48, loss tangent of 0.29 and conductivity of 1.22 S/m.

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