scholarly journals Modified Crossed-Wire Antennas Radiating a Circularly Polarized Conical Beam

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Kazuhide Hirose ◽  
Kazuhiko Hata ◽  
Hisamatsu Nakano
Keyword(s):  
Method Of Moments ◽  
Experimental Work ◽  
Axial Ratio ◽  
Wire Length ◽  
Circularly Polarized ◽  
Ratio Criterion ◽  
The Wire ◽  
Wire Antennas ◽  
Spiral Type ◽  
Conical Beam

Two types of modified crossed-wire antennas are investigated to enhance a circularly polarized (CP) wave bandwidth. The wire length of each antenna is increased twice as long as that of the original antenna. First, a bent-type antenna is analyzed using the method of moments. It is found that the CP wave bandwidth for a 3 dB axial ratio criterion is twice as wide as that of the original antenna. Next, a spiral-type antenna is analyzed. It is revealed that the antenna shows a CP wave bandwidth of 28%, which is wider than that of the original antenna by a factor of 3.5. The analysis results are validated by experimental work.

scholarly journals A Loop-Line Antenna with Enhanced Bandwidth of Circular Polarization

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Kazuhide Hirose ◽  
Motoshi Nakatsu ◽  
Hisamatsu Nakano
Keyword(s):  
Transmission Line ◽  
Circular Polarization ◽  
Method Of Moments ◽  
Axial Ratio ◽  
Circularly Polarized ◽  
Maximum Value ◽  
Ratio Criterion

We investigate a circularly polarized (CP) transmission-line antenna composed of loop radiation elements, called a loop-line antenna. To enhance the CP wave bandwidth, an isolated loop radiation element is first analyzed using the method of moments. It is found that a CP wave bandwidth for a 3 dB axial-ratio criterion has a maximum value of 8%. On the basis of the analysis results, we design the loop-line antenna. It is found that the antenna shows a CP wave bandwidth of 6%, which is twice as wide as that of a conventional loop-line antenna. The analysis results are verified with experimental ones. In addition, a condition for wideband CP radiation is discussed and found to be a composite radiation element consisting of two CP loops.

scholarly journals A Low-Profile Circularly Polarized Conical-Beam Antenna with Wide Overlap Bandwidth

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Wei He ◽  
Yejun He ◽  
Long Zhang ◽  
Sai-Wai Wong ◽  
Wenting Li ◽  
...  
Keyword(s):  
Electric Field ◽  
Patch Antenna ◽  
Ground Plane ◽  
Axial Ratio ◽  
Impedance Bandwidth ◽  
Beam Radiation ◽  
Circularly Polarized ◽  
Low Profile ◽  
Two Sides ◽  
Conical Beam

In this paper, a low-profile circularly polarized (CP) conical-beam antenna with a wide overlap bandwidth is presented. Such an antenna is constructed on the two sides of a square substrate. The antenna consists of a wideband monopolar patch antenna fed by a probe in the center and two sets of arc-hook-shaped branches. The monopolar patch antenna is loaded by a set of conductive shorting vias to achieve a wideband vertically polarized electric field. Two sets of arc-hook-shaped parasitic branches connected to the patch and ground plane can generate a horizontally polarized electric field. To further increase the bandwidth of the horizontally polarized electric field, two types of arc-hook-shaped branches with different sizes are used, which can generate another resonant frequency. When the parameters of the arc-hook-shaped branches are reasonably adjusted, a 90° phase difference can be generated between the vertically polarized electric field and the horizontally polarized electric field, so that the antenna can produce a wideband CP radiation pattern with a conical beam. The proposed antenna has a wide impedance bandwidth ( ∣ S 11 ∣ < − 10   dB ) of 35.6% (4.97-7.14 GHz) and a 3 dB axial ratio (AR) bandwidth at phi = 0 ° and theta = 35 ° of about 30.1% (4.97-6.73 GHz). Compared with the earlier reported conical-beam CP antennas, an important feature of the proposed antenna is that the AR bandwidth is completely included in the impedance bandwidth, that is, the overlap bandwidth of ∣ S 11 ∣ < − 10   dB and AR < 3   dB is 30.1%. Moreover, the stable omnidirectional conical-beam radiation patterns can be maintained within the whole operational bandwidth.

scholarly journals Desain Antena Mikrostrip Segitiga Terpancung Tunggal LHCP Patch Stack sebagai Basic Sensor CP-SAR

2020 ◽  
Vol 1 (2) ◽  
pp. 79-84
Author(s):  
Muhammad Fauzan Edy Purnomo
Keyword(s):  
Synthetic Aperture Radar ◽  
Circular Polarization ◽  
Method Of Moments ◽  
Axial Ratio ◽  
Synthetic Aperture ◽  
Circularly Polarized ◽  
Left Handed ◽  
S Parameter ◽  
Radar Applications ◽  
Aperture Radar

The development of SAR radar technology (Synthetic Aperture Radar) and aircraft as the carrier media is relatively fast and demands the need for communication facilities and infrastructure that have a variety of platforms and high-quality imaging, which can produce processed data with high resolution and good images for all type explored terrain. Based on the demands of the progress of civilization, the antenna placed on the carrier media should have simple, compact, thin, and conformal characteristics. This research will analyze and study the need for a single, low power microstrip antenna in the L-band (1.25 GHz - 1.27 GHz) for CP (Circularly Polarized)-SAR radar applications. The use of Method of Moments (MoM) show that the result of characteristic performance and S-parameter for the single triangular truncated patch stack Left-Handed Circular Polarization (LHCP) antenna, f = 1.25 GHz, are consecutively 7.23 dBic of gain, 0.51 of axial ratio, -16.35 dB of S-parameter. Moreover, the 3-dB axial ratio bandwidth LHCP antenna is around 15 MHz or the percentage around 1.2%                 Perkembangan teknologi radar SAR (Synthetic Aperture Radar) dan pesawat terbang sebagai media pembawanya relatif cepat dan menuntut kebutuhan sarana dan prasarana komunikasi yang memiliki ragam platform dan pencitraan yang berkualitas tinggi, yang mampu menghasilkan data olahan dengan resolusi tinggi dan gambar yang baik untuk segala jenis medan yang dijelajahi. Berdasarkan tuntutan kemajuan peradaban zaman, maka antena yang diletakan pada media pembawa tersebut, seyogyanya memiliki karakteristik sederhana, compact, tipis, dan conformal. Dalam makalah ini akan dianalisis dan dikaji kebutuhan antena mikrostrip tunggal berdaya rendah pada pita L (1,25  GHz - 1,27 GHz) untuk aplikasi radar CP (Circularly Polarized)-SAR. Penggunaan Method of Moments (MoM) menunjukkan bahwa hasil performansi karakteristik dan S-parameter untuk antena segitiga terpancung tunggal Left-Handed Circular Polarization (LHCP)  patch stack, f = 1.25 GHz, berturut-turut yaitu gain sebesar 7.23 dBic, axial ratio sebesar 0.51, dan S-parameter sebesar -16.35 dB. Selain itu, bandwidth axial ratio 3-dB antena LHCP sekitar 15 MHz atau persentasinya sebesar 1,2%.

Development of Wire Suspended Robot System (ARANEUS 2.0) for Bridge Inspection

10.29007/zw9k ◽  
2020 ◽  
Author(s):  
Kazuhide Nakata ◽  
Kazuki Umemoto ◽  
Kenji Kaneko ◽  
Ryusuke Fujisawa
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Concrete Surface ◽  
Wire Length ◽  
High Definition ◽  
Bridge Inspection ◽  
Robot System ◽  
Inspection Method ◽  
Aerial Vehicle ◽  
The Wire

This study addresses the development of a robot for inspection of old bridges. By suspending the robot with a wire and controlling the wire length, the movement of the robot is realized. The robot mounts a high-definition camera and aims to detect cracks on the concrete surface of the bridge using this camera. An inspection method using an unmanned aerial vehicle (UAV) has been proposed. Compared to the method using an unmanned aerial vehicle, the wire suspended robot system has the advantage of insensitivity to wind and ability to carry heavy equipments, this makes it possible to install a high-definition camera and a cleaning function to find cracks that are difficult to detect due to dirt.

A Broadband Circularly Polarized Cross-slotted Patch Antenna with Horizontal Meandered Strip (HMS)

Frequenz ◽  
2020 ◽  
Vol 74 (5-6) ◽  
pp. 191-199
Author(s):  
M. K. Verma ◽  
Binod K. Kanaujia ◽  
J. P. Saini ◽  
Padam S. Saini
Keyword(s):  
Circular Polarization ◽  
Patch Antenna ◽  
Impedance Matching ◽  
Axial Ratio ◽  
Impedance Bandwidth ◽  
Radiation Patterns ◽  
Circularly Polarized ◽  
Feeding Technique

AbstractA broadband circularly polarized slotted square patch antenna with horizontal meandered strip (HMS) is presented and studied. The HMS feeding technique provides the good impedance matching and broadside symmetrical radiation patterns. A set of cross asymmetrical slots are etched on the radiating patch to realize the circular polarization. An electrically small stub is added on the edge of the antenna for further improvement in performance. Measured 10-dB impedance bandwidth (IBW) and 3-dB axial ratio bandwidth (ARBW) of the proposed antenna are 32.31 % (3.14–4.35 GHz) and 20.91 % (3.34–4.12 GHz), respectively. The gain of the antenna is varied from 3.5 to 4.86dBi within 3-dB ARBW. Measured results matched well with the simulated results.

Bilayer split-ring chiral metamaterial based reconfigurable antenna for polarization conversion

Frequenz ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Preet Kaur ◽  
Pravin R. Prajapati
Keyword(s):  
Low Cost ◽  
Axial Ratio ◽  
Center Frequency ◽  
Impedance Bandwidth ◽  
Split Ring ◽  
Circularly Polarized ◽  
Left Hand ◽  
Rectangular Patch ◽  
Mode 2 ◽  
Chiral Metamaterial

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.).

A Single-Layer Dual Circularly Polarized SIW Cavity-Backed Patch Filtenna With Wide Axial Ratio Bandwidth

2021 ◽  
pp. 1-1
Author(s):  
Wenlei Wang ◽  
Huayan Jin ◽  
Weiliang Yu ◽  
Xiao Hong Zhang ◽  
Fan Wu ◽  
...  
Keyword(s):  
Single Layer ◽  
Axial Ratio ◽  
Circularly Polarized

scholarly journals Design of a Wideband Dual-Feed Circularly Polarized Antenna for Different Axial Ratio Requirements

2020 ◽  
pp. 1-1
Author(s):  
Lehu Wen ◽  
Steven Gao ◽  
Qi Luo ◽  
Wei Hu ◽  
Benito Sanz Izquierdo
Keyword(s):  
Axial Ratio ◽  
Circularly Polarized
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