scholarly journals A Compact Two-Level Sequentially Rotated Circularly Polarized Antenna Array forC-Band Applications

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Stefano Maddio
Keyword(s):  
Antenna Array ◽  
Return Loss ◽  
Single Layer ◽  
Axial Ratio ◽  
Gain Bandwidth ◽  
Trade Off ◽  
Left Hand ◽  
Compact Dimension ◽  
Space Filling Design ◽  
Sequential Phase

A compact circular polarized antenna array with a convenient gain/bandwidth/dimension trade-off is proposed for applications in theC-band. The design is based on the recursive application of the sequential phase architecture, resulting in a 4 × 4 array of closely packed identical antennas. The 16 antenna elements are disc-based patches operating in modal degeneration, tuned to exhibit a broad while imperfect polarization. Exploiting the compact dimension of the patches and a space-filling design for the feeding network, the entire array is designed to minimize the occupied area. A prototype of the proposed array is fabricated with standard photoetching procedure in a single-layer via less printed board of overall area 80 × 80 mm2. Adequate left-hand polarization is observed over a wide bandwidth, demonstrating a convenient trade-off between bandwidth and axial ratio. Satisfying experimental results validate the proposed design, with a peak gain of 12.6 dB at 6.7 GHz maintained within 3 dB for 1 GHz, a very wide 10 dB return loss bandwidth of 3 GHz, and a 4 dB axial ratio bandwidth of 1.82 GHz, meaning 31% of fractional bandwidth.

scholarly journals Wideband Circular Polarized Dielectric Resonator Antenna Array for Millimeter-Wave Applications

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3614
Author(s):  
Arun Kesavan ◽  
Mu’ath Al-Hassan ◽  
Ismail Ben Mabrouk ◽  
Tayeb A. Denidni
Keyword(s):  
Antenna Array ◽  
Millimeter Wave ◽  
Axial Ratio ◽  
Unit Element ◽  
Dielectric Resonator Antenna ◽  
Gain Bandwidth ◽  
Left Hand ◽  
Wide Resonance ◽  
Element Array ◽  
Peak Gain

A novel circular polarized dielectric antenna array (DRA) for millimeter-wave applications at 30 GHz is presented in this paper. The unit element array is a flower-shaped DRA fed with a cross slot. To obtain circular polarization, a sequential network combined with the cross slots is used to feed the 2×2 array. The prototype of the proposed antenna array is fabricated and measured to obtain a wide resonance bandwidth from 27 GHz to 38 GHz frequency band. Furthermore, this left-hand polarized antenna array has achieved a peak gain of 9.5 dBi with 3-dB axial ratio at 30 GHz. The proposed DRA array with wideband resonance and gain bandwidth has the potential to be used for millimeter-wave wireless communications at the 30 GHz band.

scholarly journals Dual Circularly Polarized Omnidirectional Antenna with Slot Array on Coaxial Cylinder

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Bin Zhou ◽  
Junping Geng ◽  
Zhe Li ◽  
Wenzhi Wang ◽  
Xianling Liang ◽  
...  
Keyword(s):  
Return Loss ◽  
Axial Ratio ◽  
Coaxial Cylinder ◽  
Circularly Polarized ◽  
Left Hand ◽  
Omnidirectional Antenna ◽  
Right Hand ◽  
Two Sides

A dual circularly polarized (CP) omnidirectional antenna based on slot array in coaxial cylinder structure is presented in this paper. It is constructed by perpendicular slot pairs around and along the axis of the coaxial cylinder to realize the omnidirectional CP property, and two ports are assigned in its two sides as left hand circularly polarized (LHCP) port and right hand circularly polarized (RHCP) port, respectively. The proposed antenna achieves a bandwidth of 16.4% ranging from 5.05 to 5.95 GHz with an isolation higher than 15 dB between the two CP ports, and the return loss (RL) is higher than 10 dB within the bandwidth in both of the two ports. From the measured results, the average axial ratio (AR) of the proposed antenna in omnidirectional plane is lower than 1.5 dB.

A CPW-fed reconfigurable patch antenna with circular polarization diversity

2014 ◽  
Vol 7 (6) ◽  
pp. 753-758 ◽  
Author(s):  
Ch. Sulakshana ◽  
L. Anjaneyulu
Keyword(s):  
Circular Polarization ◽  
Patch Antenna ◽  
Return Loss ◽  
Coplanar Waveguide ◽  
Axial Ratio ◽  
Polarization Diversity ◽  
Left Hand ◽  
Switching Condition ◽  
Parametric Studies ◽  
Made In

This paper presents a simple and compact coplanar waveguide (CPW)-fed circular-shaped reconfigurable patch antenna with a switchable circular polarization (CP) sense. The circular patch is cut at the ends vertically and switches are introduced to connect the patch ends. By controlling the ON/OFF status of the two switches, the polarization of the antenna can be switched between two states: left-hand circular polarization and right-hand circular polarization. The patch is designed on a very thin RT Duroid substrate of dielectric constant (εr) of 2.2 and thickness of 0.254 mm. The overall antenna dimensions are 35 × 30 mm. The antenna is designed and simulated using finite-element method -based EM simulator, HFSS. For each switching condition the return loss curve, radiation pattern are obtained. Axial ratio curves for polarization diversity cases are also plotted. Parametric studies have been made in order to get optimized values for certain antenna dimensions such as thickness, CPW ground to feed gap, etc.

Single-layer wideband circularly polarized antenna array using sequential phase feed for C-band applications

2020 ◽  
Vol 26 (6) ◽  
pp. 4163-4172
Author(s):  
K. Srinivasan ◽  
M. Balasaraswathi ◽  
C. S. Boopathi ◽  
Huy Hung Tran
Keyword(s):  
Antenna Array ◽  
Single Layer ◽  
Circularly Polarized ◽  
Sequential Phase

A Wideband Polarization Reconfigurable Antenna Array Based on Mode Combination Method

Frequenz ◽  
2019 ◽  
Vol 73 (5-6) ◽  
pp. 153-159
Author(s):  
Zhuo Mu ◽  
Shen-Yun Wang ◽  
Wen-Ying Meng
Keyword(s):  
Circular Polarization ◽  
Antenna Array ◽  
Linear Polarization ◽  
Axial Ratio ◽  
Combination Method ◽  
Impedance Bandwidth ◽  
Reconfigurable Antenna ◽  
Circularly Polarized ◽  
Left Hand ◽  
Measurement Results

Abstract This paper reports a novel polarization-reconfigurable antenna array based on the theory of mode combination (MC), which can electronically alter its polarization states between left-hand circular polarization (LCP) mode, right-hand circular polarization (RCP) mode, and two combined linear polarization (LP) modes. The array element is adopted as the L-probes fed circularly-polarized antenna reported by Luk et al. [1]. To verify the concept, a prototype of 2×2 antenna array is manufactured and tested. By properly exciting the feeding probes, four polarization modes can be switchable. Measurement results show that the proposed antenna has an overlapped −10 dB impedance bandwidth around 34 % for both CP modes and LP(2) mode, and an overlapped 3 dB axial-ratio bandwidth around 22.0 % of the CP modes. The average realized gains are around 12.4 dB for CP modes and LP(1) mode, which remain stable in the axial-ratio bandwidth.

The microtubule associated protein (MAP) tau forms a new class of triple-stranded left-hand helical fibrous protein polymer

1992 ◽  
Vol 50 (1) ◽  
pp. 540-541
Author(s):  
G. C. Ruben ◽  
K. Iqbal ◽  
I. Grundke-Iqbal ◽  
H. Wisniewski ◽  
T. L. Ciardelli ◽  
...  
Keyword(s):  
Axial Ratio ◽  
Normal Structure ◽  
Paired Helical Filaments ◽  
Left Hand ◽  
New Class ◽  
Protein Polymer ◽  
Fibrous Protein ◽  
Protein Map ◽  
Neurotransmitter Transport ◽  
Alzheimer Neurofibrillary Tangles

In neurons, the microtubule associated protein, tau, is found in the axons. Tau stabilizes the microtubules required for neurotransmitter transport to the axonal terminal. Since tau has been found in both Alzheimer neurofibrillary tangles (NFT) and in paired helical filaments (PHF), the study of tau's normal structure had to preceed TEM studies of NFT and PHF. The structure of tau was first studied by ultracentrifugation. This work suggested that it was a rod shaped molecule with an axial ratio of 20:1. More recently, paraciystals of phosphorylated and nonphosphoiylated tau have been reported. Phosphorylated tau was 90-95 nm in length and 3-6 nm in diameter where as nonphosphorylated tau was 69-75 nm in length. A shorter length of 30 nm was reported for undamaged tau indicating that it is an extremely flexible molecule. Tau was also studied in relation to microtubules, and its length was found to be 56.1±14.1 nm.

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 CPW-fed circularly-polarized antenna array with high front-to-back ratio and low-profile

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 651-655 ◽  
Author(s):  
Yilin Liu ◽  
Kama Huang
Keyword(s):  
Antenna Array ◽  
Coplanar Waveguide ◽  
Ground Plane ◽  
Axial Ratio ◽  
Antenna Design ◽  
Impedance Bandwidth ◽  
Feeding Method ◽  
Circularly Polarized ◽  
Low Profile ◽  
Novel Design

Abstract A novel design of a coplanar waveguide (CPW) feed antenna array with circular polarization (CP) and a high front-to-back ratio is described. The proposed CP array is achieved by using a compact CPW–slotline transition network etched in the ground plane. The measured results show that this kind of feeding method can improve the impedance bandwidth, as well as the axial ratio bandwidth of the CP antenna array and provide adequate gain. The proposed array can achieve a 6.08% impedance bandwidth and a 4.10% CP bandwidth. Details of the antenna design and experimental results are presented and discussed.

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