scholarly journals Mechanical stress induces a scalable circularly polarized LEO satellite antenna with Quadrifilar spiral

2021 ◽  
Vol 19 (2) ◽  
pp. 2120-2146
Author(s):  
Jie Shen ◽  
◽  
Han-min Liu ◽  
Jing Wang ◽  
◽  
...  

<abstract> <p>This paper investigates a left-hand circularly polarized (LHCP) antenna and a right-hand circularly polarized (RHCP) antenna on LEO Satellite, which is based on the phase-tuning metasurface. We overcome its inherent limitations in size, weight and power, and designed a high-gain, ultra-lightweight, scalable antenna for small satellite communications. The antenna can generate continuous and large tunability of subwavelength, with low-Q resonators. The simulated and experimental results verify that different capacitance and inductance modes can be effectively generated by rotating the spiral arms of single-arm spiral antennas with corresponding degrees, which greatly simplify the feeding network. The maximum gain of the normal position within the angle of the uplink and downlink is 4~9 dBi higher than that of the ordinary polarized antenna. In addition, the design method proposed to this article is superior to the reference system in terms of impedance bandwidth, axial ratio bandwidth, and operation frequency. The performance achievements of this paper are implemented within the bandwidth of 3 MHz of uplink and downlink, such as impedance bandwidth is 3 MHz with impedance of 50, axial ratio bandwidth is 2.5 MHz, operation frequency of uplink is 240–243 MHz, downlink is 320 MHz and 401 MHz, and the voltage standing wave ratio (VSWR) is less than 2 dB which is so called S parameter, the above parameters can meet the performance index design requirements.</p> </abstract>

Frequenz ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Preet Kaur ◽  
Pravin R. Prajapati

Abstract A bilayer split-ring chiral metamaterial converts the linearly polarized wave, into a nearly perfect left or right-handed circularly polarized wave. The proposed antenna is intended to operate at center frequency of 5.80 GHz with switchable polarization capability. The polarization re-configurability is achieved by electronically switching of two PIN-diode pairs, which are embedded into bilayer split-ring Chiral Metamaterial. The optimized length of rectangular patch is 16 mm and width is 12.1 mm. Two types of radiation characteristics offered by the proposed antenna; left hand circularly polarized in mode 1 and right hand circularly polarized in mode 2. Measured results show that its impedance bandwidth is 155 MHz from 5.70 to 5.855 GHz for both mode 1 and mode 2. The measured axial-ratio bandwidth is 100 MHz from 5.75 to 5.85 GHz for mode 1 and 110 MHz from 5.73 to 5.84 GHz for mode 2. Antenna has LHCP gain of 2.52 dBi and RHCP gain of −23 dBi in mode 1. RHCP gain of 2 dBi and polarization purity of about −20 dBi is obtained in mode 2. The proposed antenna has simple structure, low cost and it has potential application in field of wireless communication (i.e., WiMax, WLAN etc.).


Frequenz ◽  
2019 ◽  
Vol 73 (9-10) ◽  
pp. 317-320
Author(s):  
Saeid Karamzadeh ◽  
Vahid Rafiei ◽  
Hasan Saygin

Abstract In this work circularly polarization diversity has been achieved by utilizing two Schottky diodes on low profile cavity-backed substrate integrated waveguide (CBSIW). In comparison with other studies in the literature, the size of antenna has been reduced to 0.54λg × 0.76λg by helping a 50-Ohm coaxial feed line. The impedance bandwidth, axial ratio bandwidth and antenna gain are improved to 10.02 %, 5.2 % and 7.68dBi, respectively. In addition, the proposed antenna can generate either a left-hand circularly polarized (LHCP) or a right-hand circularly polarized (RHCP) radiation. The developed antenna was fabricated and tested and the achieved results were in good agreement with the simulated one.


Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5610
Author(s):  
Sachin Kumar ◽  
Gwan Hui Lee ◽  
Dong Hwi Kim ◽  
Hyun Chul Choi ◽  
Kang Wook Kim

A broadband compact-sized planar four-port multiple-input–multiple-output (MIMO) antenna with polarization diversity is presented. The proposed dual circularly polarized (CP) MIMO antenna consists of four G-shaped monopole elements, two of which are left-hand CP and the other two are right-hand CP. A vertical line strip in the G-shaped radiating element acts in balancing the vertical and horizontal electric field components to obtain 90° phase difference between them for circular polarization. Also, an I-shaped strip is incorporated between the ground planes of the G-shaped antenna elements to obtain equal voltage level in the proposed MIMO configuration. The dual circular polarization mechanism of the proposed MIMO/diversity antenna is analysed from the vector current distributions. The impedance bandwidth (S11 ≤ –10 dB) of the MIMO antenna is 105.9% (4–13 GHz) and the 3 dB axial ratio bandwidth (ARBW) is 67.7% (4.2–8.5 GHz), which is suitable for C-band applications. The overall size of the MIMO antenna is 70 × 68 × 1.6 mm3, and the minimum isolation between the resonating elements is 18 dB. The envelope correlation coefficient is less than 0.25, and the peak gain within the resonating band is 6.4 dBi.


2016 ◽  
Vol 9 (3) ◽  
pp. 697-703 ◽  
Author(s):  
Nagendra Kushwaha ◽  
Raj Kumar

This paper presents a high gain, wideband circularly polarized (CP) antenna. High gain of the antenna is achieved by employing a frequency selective surface (FSS) as a reflector. The antenna is a coplanar waveguide-fed structure with a modified L-shaped radiating patch. The unit element of the FSS is formed by connecting two modified dipoles at an angle of 90°. The antenna with reflector has a measured impedance bandwidth of 74.3% (2.2–4.8 GHz) and a 3-dB axial ratio bandwidth (ARBW) of 62% (2.2–4.18 GHz). The maximum boresight gain of the proposed antenna with reflector is 7.1 dB at 3.4 GHz. The radiation patterns of the antenna with the FSS are also measured and compared with simulated patterns. The various aspects of effect of FSS on CP antenna performance are also discussed.


Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2071
Author(s):  
Bruno Ferreira-Gomes ◽  
Osvaldo N. Oliveira ◽  
Jorge Ricardo Mejía-Salazar

We report on the design of a low-profile integrated millimeter-wave antenna for efficient and broadband circularly polarized electromagnetic radiation. The designed antenna comprises a chiral dielectric metasurface built with a 2×2 arrangement of dielectric cylinders with slanted-slots at the center. A broadbeam high-gain with wide axial ratio (AR)<3 dB bandwidth was reached by pairing the electric and magnetic resonances of the dielectric cylinders and the slanted slots when excited by an elliptically polarized driven-patch antenna. This electric-magnetic pairing can be tuned by varying the cylinders diameter and the tilting and rotation angles of the slanted slots. The simulation results indicate impedance-matching bandwidths up to 22.6% (25.3–31.6 GHz) with 3-dB AR bandwidths of 11.6% (26.9–30.2 GHz), which in terms of compactness (0.95λ0×0.95λ0) and performance are superior to previous antenna designs. Since the simulations were performed by assuming materials and geometries easily implementable experimentally, it is hoped that circularly polarized antennas based on chiral metasurfaces can be integrated into 5G and satellite communications.


2021 ◽  
Author(s):  
SACHIN KUMAR YADAV ◽  
Amanpreet Kaur ◽  
Rajesh Khanna

Abstract A circularly polarized hollow dielectric resonator antenna (CPHDRA) is designed for X-band applications. Rectangular dielectric resonator (RDR) is used as a radiator element, fed by a quarter-wave transformer (QWT) feedline. By performance of the RDR antenna, an air cylindrical rod structure is extracted from RDR to enhance the gain and impedance bandwidth. Two parasitic strips are placed on the top of the RDR to achieve circular polarization with reported ≤ 3-dB axial ratio (AR) bandwidth for X-band applications. In this article, UWB antenna covers range from 2.74 to 10.4GHz by using asymmetrical defective ground structure (DGS). In near field of the dielectric resonator, three different radiating modes namely HE11δ, HE21δ, HE23δ, and HE32δ are at 4.4, 6, 8.8, and 9.9 GHz. For the generation of circular polarization (CP), two orthogonal modes are generated at 8.8 and 9.9 GHz as per XZ and YZ planes. It has reported 23.8 % (8 to 10.1 GHz) of 3-dB AR bandwidth. The simulated and measured impedance bandwidths are 118.46 % and 121.12 % along with a peak gain of 6.55 dB without the use of a metallic reflector. By using a metallic reflector suspended in the bottom side of the substrate with a distance of 13.1mm is reported along with the peak gain of 9.8 dBi.


2015 ◽  
Vol 8 (7) ◽  
pp. 1101-1109 ◽  
Author(s):  
Pravin R. Prajapati ◽  
Amalendu Patnaik ◽  
M. V. Kartikeyan

A novel asymmetric “+” shaped fractal slotted circularly polarized microstrip antenna with a Yagi–Uda structure is proposed. Four asymmetric plus shape slots are embedded symmetrically in the center of all four quadrants of a square patch. To suppress undesirable higher modes, dumbbell-shaped defected ground structure (DGS) is introduced at the ground layer of the antenna. We introduce a method to compensate the reduction in gain occurring due to the presence of DGS, without changing in the overall size of the antenna. A 3 dB axial ratio bandwidth of 4 MHz at center frequency of 862 MHz, 10 dB impedance bandwidth of 13.20 MHz and a gain of 4.25 dB is achieved with the proposed antenna. A laboratory prototype of the proposed antenna is made to cross-verify the simulation results. Very good agreements between the two are obtained. The proposed antenna may prove useful for International Mobile Telecommunication application for designing high-gain arrays.


2018 ◽  
Vol 10 (7) ◽  
pp. 851-859 ◽  
Author(s):  
Qi Zheng ◽  
Chenjiang Guo ◽  
Jun Ding

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.


2019 ◽  
Vol 8 (3) ◽  
pp. 83-91
Author(s):  
R. S. Bhadade ◽  
S. P. Mahajan

In this paper we propose a circularly polarized pentagonal microstrip antenna on a suspended substrate with coaxial probe feed and five loaded slits for Massive MIMO BS Antenna applications. Massive Multiple-Input Multiple-Output (MIMO) is one of the key component to be incorporated in the 5G cellular systems. The proposed antenna is successfully simulated using HFSS 13.0, fabricated on a FR-4 substrate and measured. The proposed antenna exhibits a much higher gain of 6.17dB, improved impedance bandwidth of 171.9 MHz (Return loss, S11= -10dB) , axial ratio bandwidth (< 3dB) of 135 MHz , patch area of 1775 mm2  , and also yields return loss better than -15 dB around the center frequency of 2.45 GHz (ISM Band). Measured characteristics of the antenna are in good agreement with the simulated results.


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