scholarly journals Circularly Polarized Omnidirectional Antenna with Dipole Core and Diagonally Adjoined Parasitic Braces for ISM Band Applications

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Piyapong Dangkham ◽  
Sitthichai Dentri ◽  
Chuwong Phongcharoenpanich ◽  
Prayoot Akkaraekthalin
Keyword(s):  
Circular Polarization ◽  
Dipole Antenna ◽  
Experimental Results ◽  
Antenna Gain ◽  
Circularly Polarized ◽  
Ism Band ◽  
Omnidirectional Antenna ◽  
Quarter Wave ◽  
Radio Band ◽  
Good Agreement

This research proposes a circularly polarized (CP) single-fed omnidirectional dipole antenna operable in 2.45 GHz frequency for the industrial, scientific, and medical (ISM) radio band applications. The proposed antenna consisted of bisectional dipole core, a pair of quarter-wave baluns, and four diagonally adjoined parasitic braces. The bisectional dipole core was utilized to improve the antenna gain and realize omnidirectional radiation pattern, and the quarter-wave baluns were to symmetrize the current on the bisectional core. The four parasitic braces collectively generated circular polarization. In the study, simulations were conducted using CST Microwave Studio and a prototype antenna fabricated. To validate, experiments were carried out, and simulation and experimental results compared. The finding revealed good agreement between the simulation and experimental results. Essentially, in addition to achieving an antenna gain of 2.07 dBic, the proposed CP single-fed omnidirectional antenna is suited to ISM frequency band applications.

scholarly journals A Single Feed Circularly Polarized Planar Antenna Array

2019 ◽  
Vol 9 (2) ◽  
pp. 657-661
Keyword(s):  
Circular Polarization ◽  
Antenna Array ◽  
Communication Systems ◽  
Planar Antenna ◽  
Circularly Polarized ◽  
Quarter Wave ◽  
Feed Network ◽  
Polarization Characteristics ◽  
Structural Simplicity ◽  
Planar Antenna Array

A design of a circularly polarized planar antenna array of elliptical patches is presented. The designed prototype has been verified experimentally. Elliptical patches produce circular polarization by using a single feed only. A corporate feed network with quarter-wave transformers are used for uniform excitation of all the array elements. Primary advantages of the presented antenna array are structural simplicity, good circular polarization characteristics and no side lobes. Here, the design example is given for 2×2 elliptical patches at 2.8 GHz. Similar procedure can be extended for more number of array elements at the desired frequency of operation to cater the need of communication systems where circular polarization is essential.

A Laboratory Measurement Method of Antenna Gain

2012 ◽  
Vol 220-223 ◽  
pp. 1953-1956
Author(s):  
Hui Xie ◽  
Lin Zhao ◽  
Yu Jun Liang
Keyword(s):  
Laboratory Experiment ◽  
Direct Measurement ◽  
Measurement Method ◽  
Laboratory Measurement ◽  
Electrical Characteristics ◽  
Antenna Gain ◽  
Antenna Measurement ◽  
Measurement Result ◽  
Omnidirectional Antenna ◽  
Quarter Wave

Antenna gain is one of the most important electrical characteristics that are of interest to obtain by direct measurement in laboratory experiment. This paper introduced a laboratory measurement method of antenna gain, and demonstrated this experiment in detailed steps such as measurement environment surrounding the antenna, measurement preparation, measurement points for attention, etc. A quarter wave omnidirectional antenna, a collinear omnidirectional antenna, a biquad antenna and a cantenna were shown as models, and the measurement result is fully consistent with theoretical value.

scholarly journals A Multi-Band U-Strip and SRR Loaded Slot Antenna with Circular Polarization Characteristics

2020 ◽  
Vol 9 (1) ◽  
pp. 41-48
Author(s):  
P. M. Paul ◽  
K. Kandasamy ◽  
M. S. Sharawi
Keyword(s):  
Circular Polarization ◽  
Ring Resonator ◽  
Axial Ratio ◽  
Split Ring Resonator ◽  
Slot Antenna ◽  
Impedance Bandwidth ◽  
Split Ring ◽  
Circularly Polarized ◽  
Polarization Characteristics ◽  
Good Agreement

A compact multiband circularly polarized slot antenna is proposed here. An F-shaped microstrip feedline is used to excite the square slot antenna loaded with a U-shaped strip and a split ring resonator (SRR) to generate three circularly polarized bands at 1.5 GHz, 2.75 GHz and 3.16 GHz. A meandered slot is used in the feedline and the U-strip to improve the axial ratio bandwidth (ARBW). The meandered feedline excites the slot to produce resonance at 2.5 GHz. This resonance along with that of the F-shaped feed, loaded SRR and U-strip combine to give rise to three circularly polarized bands which can be tuned depending on the feed, SRR and U-strip dimensions. The orientation of the F-shaped feed decides the sense of polarization of the three circularly polarized bands of the proposed antenna. The proposed antenna is fabricated on a substrate of FR4 material with dimensions 50 x 50 x 1.56 mm3. The antenna is prototyped and measured in terms of impedance bandwidth, ARBW, gain and efficiency. The simulated and measured results show reasonably good agreement.

scholarly journals A Miniaturized Circularly-Polarized Antenna for In-Body Wireless Communications

Micromachines ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 70 ◽  
Author(s):  
Yi Fan ◽  
Xiongying Liu ◽  
Jiming Li ◽  
Tianhai Chang
Keyword(s):  
Wireless Communications ◽  
Ex Vivo ◽  
Axial Ratio ◽  
Impedance Bandwidth ◽  
Circularly Polarized ◽  
Ism Band ◽  
Left Handed ◽  
Current Path ◽  
Implantable Antenna ◽  
Good Agreement

A novel miniaturized single-fed circularly-polarized (CP) microstrip patch antenna operating in the Industrial, Scientific, Medical (ISM) band of 2.40–2.48 GHz, is comprehensively proposed for implantable wireless communications. By employing reactive loading in the arrow-shaped slotted patch to form slow wave effect and embedding V-shaped slots into patch to lengthen the current path, the proposed implantable antenna is minimized with the overall dimensions of 9.2 mm × 9.2 mm × 1.27 mm. The radiation patterns of the proposed antenna illustrate the performance of left-handed circular polarization. The simulated results show that an impedance bandwidth of 7.2% (2.39–2.57 GHz) and an axial ratio bandwidth of 3.7% (2.39–2.48 GHz) at the ISM band are achieved, respectively. Ex vivo measured results are in good agreement with the corresponding simulated ones.

scholarly journals A novel compact dual band RFID handheld reader antenna for microwave ISM band application

2021 ◽  
Vol 23 (1) ◽  
pp. 321
Author(s):  
Wahiba Belgacem ◽  
Miloud Bousahla ◽  
Sidi Mohammed Meriah
Keyword(s):  
Parametric Study ◽  
Relative Permittivity ◽  
Experimental Results ◽  
Dual Band ◽  
Medical Applications ◽  
Ism Band ◽  
Rfid Reader ◽  
Reader Antenna ◽  
Good Agreement ◽  
Cst Microwave Studio

This paper presents a new design of dual band RFID reader antenna for ISM-band industrial science and medical applications at 2.4 GHz and 5.8 GHz. Theantenna is designed and physically built using FR4 substrate and taking a 1.5 thickness, 4.3 relative permittivity and 0.025 loss tangents. Different slots havebeen introduced to reduce the antenna dimensions and to achieve the dual bandfor microwave ISM band application. The dimension of the proposed antenna is 34 × 34 × 1.5 mm3, which it could be easily integrated into RFID readers.Numerical simulations have been performed usingcomputer simulationtechnology (CST) Microwave Studio software. A parametric study wasinvestigated in order to show the effect of slots variation and to obtain the desiredfunctional characteristics. Experimental results show a good agreement withresults obtained by simulations. A satisfactorily omnidirectional for the radiationpatterns across the antenna operation bands was obtained.

scholarly journals A Very Wideband Circularly Polarized Crossed Straight Dipole Antenna with Cavity Reflector and Single Parasitic Element

2018 ◽  
Vol 8 (1-2) ◽  
Author(s):  
Huy Hung Tran ◽  
Minh Thuan Doan ◽  
Cong Danh Bui ◽  
Nguyen Truong Khang
Keyword(s):  
Circular Polarization ◽  
Axial Ratio ◽  
Dipole Antenna ◽  
Impedance Bandwidth ◽  
Circularly Polarized ◽  
Parasitic Element ◽  
Proper Size ◽  
Radiating Element ◽  
Final Design ◽  
Operating Bandwidth

A very wideband circularly polarized (CP) crossed dipole antenna is presented in this paper. The primary radiating element of the antenna consists of two straight dipoles arranged orthogonally through double printed rings. To further enhance the axial ratio bandwidth, a cavity with proper size and single parasitic element are employed to generate two additional bands. The use of cavity reflector is investigated thoroughly, providing a solid framework for designing this type of antennas. The final design with an overall size of 0.92λo × 0.92λo × 0.32λo at the center CP frequency yields a measured –10 dB-impedance bandwidth of 75.2% and 3 dB-axial ratio bandwidth of 67.7%. The proposed antenna exhibits right-handed circular polarization and an average broadside gain of about 8.3 dBi over the CP operating bandwidth.

Dual-band stacked circularly polarized microstrip antenna for S and C band applications

2015 ◽  
Vol 8 (8) ◽  
pp. 1215-1222 ◽  
Author(s):  
Sachin Kumar ◽  
Abhishek Sharma ◽  
Binod K. Kanaujia ◽  
Mukesh K. Khandelwal ◽  
Anil Kumar Gautam
Keyword(s):  
Circular Polarization ◽  
Microstrip Antenna ◽  
Dual Band ◽  
Impedance Bandwidth ◽  
Radiation Characteristics ◽  
Antenna Structure ◽  
Circularly Polarized ◽  
Patch Structure ◽  
Dual Band Antenna ◽  
Good Agreement

A single-fed circularly polarized microstrip antenna is proposed where the antenna structure exhibits truncated corners in the radiating square patch. The truncated corners square patch structure is loaded with a circular slot and is resonating at 2.25 GHz with circular polarization. Furthermore, the proposed antenna is stacked using an upper circular patch thus achieving a dual-band circularly polarized pattern. The dual-band antenna resonates at 2.25 GHz in the first band and with impedance bandwidth ranging from 4.4 to 5.5 GHz in the second band. The size of the proposed stacked structure is compact compared with the conventional circularly polarized stacked antenna designs. Proposed structures are fabricated and fed using Subminiature version A (SMA) connector. The measured results are in good agreement with the simulated. The antenna shows stable radiation characteristics for the entire band of operation.

scholarly journals Dual-Frequency Circularly Polarized Truncated Square Aperture Patch Antenna with Slant Strip and L-Shaped Slot for WLAN Applications

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Sorana Niyamanon ◽  
Rewat Senathong ◽  
Chuwong Phongcharoenpanich
Keyword(s):  
Radiation Pattern ◽  
Patch Antenna ◽  
Axial Ratio ◽  
Experimental Results ◽  
Antenna Design ◽  
Impedance Bandwidth ◽  
Dual Frequency ◽  
Circularly Polarized ◽  
Good Agreement

This research proposes a dual-frequency circularly polarized truncated square aperture patch antenna with slant stripline and L-shaped slot for WLAN applications. In the antenna design, the parameters were optimized and the WLAN-enabled dual-frequency (2.4 and 5.8 GHz) antenna was realized. Simulations were subsequently carried out for the impedance bandwidth (S11) < −10 dB, axial ratio (AR) ≤ 3 dB, optimal gain, and bidirectional radiation pattern. To validate, an antenna prototype was fabricated and the experiments were undertaken. The simulated and experimental results are in good agreement. In essence, the proposed WLAN-enabled dual-frequency circularly polarized antenna is most suited for applications in the vertically and horizontally elongated areas, including in the tunnel, train carriage, and buildings.

scholarly journals A Liquid Metal Conical Helical Antenna for Circular Polarization-Reconfigurable Antenna

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Yun Zhou ◽  
Shaojun Fang ◽  
Hongmei Liu ◽  
Shiqiang Fu
Keyword(s):  
Liquid Metal ◽  
Circular Polarization ◽  
Pitch Angle ◽  
Axial Ratio ◽  
Experimental Results ◽  
Reconfigurable Antenna ◽  
Polarization Mode ◽  
Helical Antenna ◽  
Left Hand ◽  
Good Agreement

A novel polarization-reconfigurable conical helical antenna based on the liquid metal is presented. The antenna is implemented by using truncated structure, variable pitch angle, a matching stub, and a mechanical autorotation device. The experimental results show that a good agreement between simulations and measurements is obtained. The gain of the antenna achieves higher than 8 dBi in the work band (1525–1660.5 MHz), and the 3 dB axial ratio (AR) bandwidth reaches 410 MHz. The polarization mode of the antenna can be switched between right-hand and left-hand circular polarization.

Inducing Frictional Force to Enhance the Transient Response in Beams

2019 ◽  
Vol 22 (2) ◽  
pp. 88-93
Author(s):  
Hamed Khanger Mina ◽  
Waleed K. Al-Ashtrai
Keyword(s):  
Numerical Analysis ◽  
Transient Response ◽  
Frictional Force ◽  
Damping Ratio ◽  
Experimental Results ◽  
Damping Capacity ◽  
Tightening Force ◽  
Contact Areas ◽  
Good Agreement ◽  
Ansys Workbench

This paper studies the effect of contact areas on the transient response of mechanical structures. Precisely, it investigates replacing the ordinary beam of a structure by two beams of half the thickness, which are joined by bolts. The response of these beams is controlled by adjusting the tightening of the connecting bolts and hence changing the magnitude of the induced frictional force between the two beams which affect the beams damping capacity. A cantilever of two beams joined together by bolts has been investigated numerically and experimentally. The numerical analysis was performed using ANSYS-Workbench version 17.2. A good agreement between the numerical and experimental results has been obtained. In general, results showed that the two beams vibrate independently when the bolts were loosed and the structure stiffness is about 20 N/m and the damping ratio is about 0.008. With increasing the bolts tightening, the stiffness and the damping ratio of the structure were also increased till they reach their maximum values when the tightening force equals to 8330 N, where the structure now has stiffness equals to 88 N/m and the damping ratio is about 0.062. Beyond this force value, increasing the bolts tightening has no effect on stiffness of the structure while the damping ratio is decreased until it returned to 0.008 when the bolts tightening becomes immense and the beams behave as one beam of double thickness.

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