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 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 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

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.

scholarly journals A theoretical and numerical approach for selecting miniaturized antenna topologies on magneto-dielectric substrates

2015 ◽  
Vol 7 (3-4) ◽  
pp. 369-377 ◽  
Author(s):  
Alex Pacini ◽  
Alessandra Costanzo ◽  
Diego Masotti
Keyword(s):  
Near Field ◽  
Dielectric Materials ◽  
Numerical Approach ◽  
Operating Conditions ◽  
Microwave Range ◽  
Dielectric Substrates ◽  
Full Wave ◽  
Miniaturized Antenna ◽  
Wavelength Radiation ◽  
Definition Of

An increasing interest is arising in developing miniaturized antennas in the microwave range. However, even when the adopted antennas dimensions are small compared with the wavelength, radiation performances have to be preserved to keep the system-operating conditions. For this purpose, magneto-dielectric materials are currently exploited as promising substrates, which allows us to reduce antenna dimensions by exploiting both relative permittivity and permeability. In this paper, we address generic antennas in resonant conditions and we develop a general theoretical approach, not based on simplified equivalent models, to establish topologies most suitable for exploiting high permeability and/or high-permittivity substrates, for miniaturization purposes. A novel definition of the region pertaining to the antenna near-field and of the associated field strength is proposed. It is then showed that radiation efficiency and bandwidth can be preserved only by a selected combinations of antenna topologies and substrate characteristics. Indeed, by the proposed independent approach, we confirm that non-dispersive magneto-dielectric materials with relative permeability greater than unit, can be efficiently adopted only by antennas that are mainly represented by equivalent magnetic sources. Conversely, if equivalent electric sources are involved, the antenna performances are significantly degraded. The theoretical results are validated by full-wave numerical simulations of reference topologies.

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