scholarly journals Design of a Highly Miniaturized, Inherently Matched, Spherical Folded Dipole Antenna and Evaluation of its Quality Factor

2021 ◽  
Author(s):  
Ashwin Iyer ◽  
Sanghamitro Das
Keyword(s):  
Quality Factor ◽  
Impedance Matching ◽  
Three Dimensional ◽  
Dipole Antenna ◽  
Full Wave ◽  
Source Impedance ◽  
Miniaturized Antenna ◽  
Folded Dipole ◽  
High Degree ◽  
Full Volume

<div>A highly miniaturized three-dimensional spherical folded dipole antenna has been reported, for which inherent impedance matching is achieved with respect to a practical source impedance by employing a simple series-LC loading combination, thereby engineering its input impedance. In order to maximize its bandwidth, the miniaturized antenna employs a spherical helix structure as the folded arm that occupies the full volume of the corresponding Chu sphere. A bifilar (two folded arms) and a quadrifilar (four folded arms) helix loaded folded dipole antenna are designed, and full-wave simulations show that both the resulting antennas demonstrate excellent impedance matching when miniaturized by 85% in comparison to a resonant dipole operating at the same frequency. Despite the high degree of miniaturization, the resulting radiation efficiencies for the bifilar and quadrifilar antennas are found to be 87.1% and 90.6%, respectively. Furthermore, various quality-factor definitions are explored for the quadrifilar antenna, and it is observed that the resulting quality factor is around 1.83 (1.22) times that predicted by the Chu (Thal) lower bound.</div>

scholarly journals Design of a Highly Miniaturized, Inherently Matched, Spherical Folded Dipole Antenna and Evaluation of its Quality Factor

2021 ◽  
Author(s):  
Ashwin Iyer ◽  
Sanghamitro Das
Keyword(s):  
Lower Bound ◽  
Quality Factor ◽  
Impedance Matching ◽  
Three Dimensional ◽  
Dipole Antenna ◽  
Fractional Bandwidth ◽  
Full Wave ◽  
Source Impedance ◽  
Miniaturized Antenna ◽  
Folded Dipole

<div>A highly miniaturized three-dimensional spherical folded dipole antenna has been reported, for which inherent impedance matching is achieved with respect to a practical source impedance by employing a simple series-LC loading combination, thereby engineering its input impedance. In order to maximize its bandwidth, the miniaturized antenna employs a bifilar spherical helix that maximizes use of the volume of the corresponding Chu sphere. Full-wave simulations show that the resulting antenna demonstrates excellent impedance matching and over 95% radiation efficiency even when miniaturized by 85% in comparison to a resonant dipole operating at the same frequency. Furthermore, various quality-factor definitions for the miniaturized spherical folded dipole antenna were estimated. It is observed that, owing to the use of proximate but non-overlapping resonances, two of these definitions fall below the Chu lower bound around the frequency of operation, resulting in a fractional bandwidth larger than that predicted by the Chu limit.</div>

scholarly journals Design of a Highly Miniaturized, Inherently Matched, Spherical Folded Dipole Antenna and Evaluation of its Quality Factor

2021 ◽  
Author(s):  
Ashwin Iyer ◽  
Sanghamitro Das
Keyword(s):  
Lower Bound ◽  
Quality Factor ◽  
Impedance Matching ◽  
Three Dimensional ◽  
Dipole Antenna ◽  
Fractional Bandwidth ◽  
Full Wave ◽  
Source Impedance ◽  
Miniaturized Antenna ◽  
Folded Dipole

<div>A highly miniaturized three-dimensional spherical folded dipole antenna has been reported, for which inherent impedance matching is achieved with respect to a practical source impedance by employing a simple series-LC loading combination, thereby engineering its input impedance. In order to maximize its bandwidth, the miniaturized antenna employs a bifilar spherical helix that maximizes use of the volume of the corresponding Chu sphere. Full-wave simulations show that the resulting antenna demonstrates excellent impedance matching and over 95% radiation efficiency even when miniaturized by 85% in comparison to a resonant dipole operating at the same frequency. Furthermore, various quality-factor definitions for the miniaturized spherical folded dipole antenna were estimated. It is observed that, owing to the use of proximate but non-overlapping resonances, two of these definitions fall below the Chu lower bound around the frequency of operation, resulting in a fractional bandwidth larger than that predicted by the Chu limit.</div>

scholarly journals Microstrip Folded Dipole Antenna for 35 GHz MMW Communication

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Guang Hua ◽  
Chen Yang ◽  
Ping Lu ◽  
Hou-Xing Zhou ◽  
Wei Hong
Keyword(s):  
Input Impedance ◽  
Low Cost ◽  
Design Procedure ◽  
Dipole Antenna ◽  
Feed Line ◽  
Low Profile ◽  
Mode Method ◽  
Miniaturized Antenna ◽  
On Chip ◽  
Folded Dipole

A microstrip asymmetric folded dipole antenna on chip is proposed in this paper. The construction of balun feed line is adopted to provide wideband. A new design procedure based on the odd-even mode method to calculate the input impedance of an asymmetric strip folded dipole antenna is presented. The folded dipole antenna has the advantage of small size, low profile, low cost, and so forth. The measured results show that a miniaturized antenna has the bandwidth of more than 14.2% (VSWR≤2); gain of the antenna is 5.7 dB at 35 GHz.

scholarly journals Optimized Wideband Impedance Matching Balun for Conducting Two-Arm Antennas

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Khalid F. A. Hussein
Keyword(s):  
Impedance Matching ◽  
Three Dimensional ◽  
Optimization Procedure ◽  
Coaxial Line ◽  
Dipole Antenna ◽  
Load Impedance ◽  
Bowtie Antenna ◽  
Dimensional Parameters ◽  
Step Transition ◽  
Diameter Change

A split coaxial balun with a step transition of the inner conductor diameter is introduced to satisfy impedance matching between unbalanced feeder and balanced antennas. The location of the step transition along the axis of the balun and the diameter change are two dimensional parameters that are not present in the conventional split coaxial balun. These additional parameters, together with the double slot width, provide more flexibility to design the balun for better impedance matching. The effects of the three dimensional parameters on the input impedance seen at the (unbalanced) coaxial line side of the balun are investigated when it is terminated with specific lumped impedance at its (balanced) split side. An optimization procedure is introduced to arrive at the balun dimensional parameters to give the best matching with specific load impedance. The proposed balun is designed to feed (balanced) two-arm antennas such as the dipole and the bowtie antenna from 50 Ω-coaxial line. The electromagnetic simulation shows that the proposed balun results in a perfect impedance matching. A comparison with the performance of the conventional split balun used to feed a dipole antenna shows that the balun proposed in the present paper gives a much lower value of the return loss at the design frequency and a wider bandwidth for VSWR ≤ 1.5. The simulation results obtained using the MoM are compared with experimental measurements showing good agreement.

Wideband 3D Folded Dipole Antenna with Feed Line for Small Terminal

2013 ◽  
Vol E96.B (10) ◽  
pp. 2410-2416 ◽  
Author(s):  
Tsutomu ITO ◽  
Mio NAGATOSHI ◽  
Shingo TANAKA ◽  
Hisashi MORISHITA
Keyword(s):  
Dipole Antenna ◽  
Feed Line ◽  
Folded Dipole

scholarly journals A 3D hydrodynamic flow-focusing device for cell sorting

2021 ◽  
Vol 25 (3) ◽  
Author(s):  
Xiaofei Yuan ◽  
Andrew Glidle ◽  
Hitoshi Furusho ◽  
Huabing Yin
Keyword(s):  
Cell Sorting ◽  
Control Strategies ◽  
Three Dimensional ◽  
Hydrodynamic Flow ◽  
Proof Of Concept ◽  
Flow Focusing ◽  
Hydrodynamic Focusing ◽  
Cell Handling ◽  
Fluid Flow Control ◽  
High Degree

AbstractOptical-based microfluidic cell sorting has become increasingly attractive for applications in life and environmental sciences due to its ability of sophisticated cell handling in flow. The majority of these microfluidic cell sorting devices employ two-dimensional fluid flow control strategies, which lack the ability to manipulate the position of cells arbitrarily for precise optical detection, therefore resulting in reduced sorting accuracy and purity. Although three-dimensional (3D) hydrodynamic devices have better flow-focusing characteristics, most lack the flexibility to arbitrarily position the sample flow in each direction. Thus, there have been very few studies using 3D hydrodynamic flow focusing for sorting. Herein, we designed a 3D hydrodynamic focusing sorting platform based on independent sheath flow-focusing and pressure-actuated switching. This design offers many advantages in terms of reliable acquisition of weak Raman signals due to the ability to precisely control the speed and position of samples in 3D. With a proof-of-concept demonstration, we show this 3D hydrodynamic focusing-based sorting device has the potential to reach a high degree of accuracy for Raman activated sorting.

scholarly journals Comparative Study of Silk Fibroin-Based Hydrogels and Their Potential as Material for 3-Dimensional (3D) Printing

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3887
Author(s):  
Watcharapong Pudkon ◽  
Chavee Laomeephol ◽  
Siriporn Damrongsakkul ◽  
Sorada Kanokpanont ◽  
Juthamas Ratanavaraporn
Keyword(s):  
3D Printing ◽  
Silk Fibroin ◽  
Biomedical Applications ◽  
Mechanical Stability ◽  
Three Dimensional ◽  
Structure Stability ◽  
3 Dimensional ◽  
Critical Technology ◽  
Box Structure ◽  
High Degree

Three-dimensional (3D) printing is regarded as a critical technology in material engineering for biomedical applications. From a previous report, silk fibroin (SF) has been used as a biomaterial for tissue engineering due to its biocompatibility, biodegradability, non-toxicity and robust mechanical properties which provide a potential as material for 3D-printing. In this study, SF-based hydrogels with different formulations and SF concentrations (1–3%wt) were prepared by natural gelation (SF/self-gelled), sodium tetradecyl sulfate-induced (SF/STS) and dimyristoyl glycerophosphorylglycerol-induced (SF/DMPG). From the results, 2%wt SF-based (2SF) hydrogels showed suitable properties for extrusion, such as storage modulus, shear-thinning behavior and degree of structure recovery. The 4-layer box structure of all 2SF-based hydrogel formulations could be printed without structural collapse. In addition, the mechanical stability of printed structures after three-step post-treatment was investigated. The printed structure of 2SF/STS and 2SF/DMPG hydrogels exhibited high stability with high degree of structure recovery as 70.4% and 53.7%, respectively, compared to 2SF/self-gelled construct as 38.9%. The 2SF/STS and 2SF/DMPG hydrogels showed a great potential to use as material for 3D-printing due to its rheological properties, printability and structure stability.

Investigation of e-textile dipole antenna performance based on embroidery parameters

2021 ◽  
pp. 004051752110134
Author(s):  
Daniel Agu ◽  
Rachel J Eike ◽  
Allyson Cliett ◽  
Dawn Michaelson ◽  
Rinn Cloud ◽  
...  
Keyword(s):  
Frequency Band ◽  
Impedance Matching ◽  
Dipole Antenna ◽  
Water Soluble ◽  
Wearable Sensor ◽  
Dipole Antennas ◽  
Antenna Performance ◽  
Large Production ◽  
Lower Transmission ◽  
The Ideal

E-textile antennas have the potential to be the premier on-body wearable sensor. Embroidery techniques, which can be applied to produce e-textile antennas, assist in large production volumes and fast production speeds. This paper focuses on the effects of three commonly used embroidery parameters, namely stitch type, conductive thread location, and stabilizer, on the performance of embroidered dipole antennas in order to determine the ideal embroidery combination for optimal antenna performance. Fifty-four dipole antenna samples were fabricated and measured at the industrial, scientific, and medical (ISM) frequency band of 2.45 GHz. The results of this study show that machine-embroidered antenna designs with satin stitches resonate at a lower frequency and exhibit a lower transmission gain compared with those made with contour stiches, and the conductive thread location in the bobbin location plus the use of a water-soluble stabilizer can help improve impedance matching.

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