scholarly journals Frequency-Diverse Bunching Metamaterial Antenna for Coincidence Imaging

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1817 ◽  
Author(s):  
Mengran Zhao ◽  
Shitao Zhu ◽  
Jianxing Li ◽  
Hongyu Shi ◽  
Juan Chen ◽  
...  
Keyword(s):  
Reflection Coefficient ◽  
Random Distribution ◽  
Correlation Coefficients ◽  
Radiation Efficiency ◽  
Circular Array ◽  
Radiation Patterns ◽  
Ka Band ◽  
Metamaterial Antenna ◽  
Imaging Experiment ◽  
Coincidence Imaging

A frequency-diverse bunching metamaterial antenna for coincidence imaging in the Ka band is proposed in this paper. The bunching metamaterial antenna includes a broadband circular array and a frequency-diverse bunching metalens. Firstly, in order to enhance the bunching characteristic, the broadband circular array is designed based on the 60-degree beamwidth design to generate radiation patterns from 32 GHz to 36 GHz. Then, types of metamaterial elements with different transmission phases are selected to form the frequency-diverse bunching metalens based on a random distribution design and gradient zoom coefficient design. Moreover, the bunching metamaterial antenna is constituted by loading the frequency-diverse bunching metalens to the broadband circular array, which can generate frequency-diverse bunching random radiation patterns with beamwidth less than 100 degrees from 32 GHz to 36 GHz. Furthermore, the performances of the bunching metamaterial antenna, including the reflection coefficient, the radiation efficiency, and the correlation coefficients of radiation patterns at different frequencies are evaluated. Finally, the coincidence imaging experiment is implemented using the bunching metamaterial antenna and the image of the target is reconstructed successfully. The design is verified by simulations and measurements.

scholarly journals Performance Analyses of the Radio Orbital Angular Momentum Steering Technique Based on Ka-Band Antenna

2017 ◽  
Vol 2017 ◽  
pp. 1-12
Author(s):  
Mingtuan Lin ◽  
Yue Gao ◽  
Peiguo Liu ◽  
Zhiqing Guo
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Circular Array ◽  
Radiation Patterns ◽  
Transmission Performance ◽  
Ka Band ◽  
Performance Analyses

The misalignment in the orbital angular momentum- (OAM-) based system would distort the radiation patterns of twisted beams carrying OAM, consequently making the OAM-based communication infeasible. To tackle the misalignment problem, a radio OAM steering technique based on a uniform circular array (UCA) is illustrated. Subsequently, simulations are conducted to explore the influence of the OAM steering on the OAM mode quality and transmission performance. Furthermore, UCAs working at Ka-band with formulated feeding networks are designed and fabricated to analyze the performance of the OAM steering. The influences of OAM steering on mode quality and orthogonality are then evaluated in the experiment. Overall, the analyses of OAM steering technique are beneficial for the development of radio OAM study.

scholarly journals Effects of Different Substrates on Rectangular Microstrip Patch Antenna for X-band

2018 ◽  
Vol 7 (2) ◽  
pp. 91-95
Author(s):  
Imran Khan ◽  
D. Geetha Devanagavi ◽  
K. R. Sudhindra ◽  
S. Prathibha ◽  
C. Shruthi . ◽  
...  
Keyword(s):  
Reflection Coefficient ◽  
Radiation Pattern ◽  
Patch Antenna ◽  
Microstrip Patch Antenna ◽  
Radiation Efficiency ◽  
Radiation Patterns ◽  
Microstrip Patch ◽  
X Band ◽  
Rectangular Microstrip Patch Antenna

In this paper, the performance of Microstrip Patch Antenna (MSPA) is analyzed by changing the substrate materials. MSPA is designed to operate with the fixed dimensions of ????????×????????×????.???????????????? for three substrate materials. A comparison has been done in terms of reflection coefficient (S11), gain, efficiency (η), radiation pattern and cost. The simulated results show very good performance with TLC substrate as compared to FR4 and RT Duroid by showing good radiation efficiency for all the three bands viz 7.0, 9.6 and 10.8 GHz with the efficiency of 99%, 99% and 96% respectively, stable radiation patterns, gain of 1.32, 1.81 and 2.0 dB. FR-4 and RT Duroid produces two bands each of 8.4/ 9.6 GHz and 11.1/12.0 GHz respectively which shows a gain of 1.29/1.36 dB for FR4 and 1.04/7.95 dB for RT Duroid along with efficiency of 68%/ 60% and 96%/96% respectively with acceptable bandwidth. The Antenna is simulated using HFSS simulator solution software.

scholarly journals A Ka-Band Cylindrical Paneled Reflectarray Antenna

Electronics ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 654 ◽  
Author(s):  
Francesco Greco ◽  
Luigi Boccia ◽  
Emilio Arnieri ◽  
Giandomenico Amendola
Keyword(s):  
High Gain ◽  
Cylindrical Symmetry ◽  
Radiation Efficiency ◽  
Ka Band ◽  
Cylindrical Reflector ◽  
Geometric Relation ◽  
Reflectarray Antenna ◽  
Parabolic Reflectors ◽  
Reflecting Surface ◽  
Continuous Metal

Cylindrical parabolic reflectors have been widely used in those applications requiring high gain antennas. Their design is dictated by the geometric relation of the parabola, which relate the feed location, f, to the radiating aperture, D. In this work, the use of reflectarrays is proposed to increase D without changing the feed location. In the proposed approach, the reflecting surface is loaded with dielectric panels where the phase of the reflected field is controlled using continuous metal strips of variable widths. This solution is enabled by the cylindrical symmetry and, with respect to rectangular patches or to other discrete antennas, it provides increased gain. The proposed concept has been evaluated by designing a Ka-band antenna operating in the Rx SatCom band (19–21 GHz). A prototype has been designed and the results compared with the ones of a parabolic cylindrical reflector using the same feed architecture. Simulated results have shown how this type of antenna can provide higher gain in comparison to the parabolic counterpart, reaching a radiation efficiency of 65%.

scholarly journals Radar Coincidence Imaging With a Uniform Circular Array

IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 105226-105236
Author(s):  
Rui Li ◽  
Ying Luo ◽  
Qun Zhang ◽  
Yi-Jun Chen ◽  
Dan Wang
Keyword(s):  
Circular Array ◽  
Coincidence Imaging

scholarly journals Metamaterial Inspired Microstrip Antenna Investigations Using Metascreens

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Muhammad Tauseef Asim ◽  
Mushtaq Ahmed
Keyword(s):  
Low Cost ◽  
Cell Structure ◽  
Unit Cell ◽  
Dual Band ◽  
Impedance Bandwidth ◽  
Radiation Patterns ◽  
Wireless Applications ◽  
Left Handed ◽  
Metamaterial Antenna ◽  
Unit Cell Structure

A dual layer periodically patterned metamaterial inspired antenna on a low cost FR4 substrate is designed, simulated, fabricated, and tested. The eigenmode dispersion simulations are performed indicating the left handed metamaterial characteristics and are tunable with substrate permittivity. The same metamaterial unit cell structure is utilized to fabricate a metascreen. This metascreen is applied below the proposed metamaterial antenna and next used as superstrate above a simple patch to study the effects on impedance bandwidth, gain, and radiation patterns. The experimental results of these antennas are very good and closely match with the simulations. More importantly, the resonance for the proposed metamaterial antenna with metascreen occurs at the left handed (LH) eigenfrequency of the metamaterial unit cell structure. The measured −10 dB bandwidths are 14.56% and 22.86% for the metamaterial antenna with single and double metascreens, respectively. The metascreens over the simple patch show adjacent dual band response. The first and second bands have measured −10 dB bandwidths of 9.6% and 16.66%. The simulated peak gain and radiation efficiency are 1.83 dBi and 74%, respectively. The radiation patterns are also very good and could be useful in the UWB wireless applications.

A metamaterial antenna with frequency-scanning omnidirectional radiation patterns

2012 ◽  
Vol 101 (17) ◽  
pp. 173501 ◽  
Author(s):  
He-Xiu Xu ◽  
Guang-Ming Wang ◽  
Mei-Qing Qi ◽  
Zhi-Ming Xu
Keyword(s):  
Radiation Patterns ◽  
Frequency Scanning ◽  
Metamaterial Antenna
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