scholarly journals Resonant Elements for Tunable Reflectarray Antenna Design

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
M. Y. Ismail ◽  
M. Inam
Keyword(s):  
Single Layer ◽  
Scattering Parameter ◽  
Accurate Analysis ◽  
Band Frequency ◽  
Rectangular Patch ◽  
Phase Errors ◽  
X Band ◽  
Phase Range ◽  
Finite Integral ◽  
Reflectarray Antenna

This paper presents an accurate analysis of different configurations of reflectarray resonant elements that can be used for the design of passive and tunable reflectarrays. Reflection loss and bandwidth performances of these reflectarray elements have been analyzed in the X-band frequency range with the Finite Integral Method technique, and the results have been verified by the waveguide scattering parameter measurements. The results demonstrate a reduction in the phase errors offering an increased static linear phase range of 225° which allows to improve the bandwidth performance of single layer reflectarray antenna. Moreover a maximum dynamic phase range of 320° and a volume reduction of 22.15% have been demonstrated for a 10 GHz reflectarray element based on the use of rectangular patch with an embedded circular slot.

scholarly journals Development of a Pin Diode-Based Beam-Switching Single-Layer Reflectarray Antenna

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Muhammad Inam Abbasi ◽  
Muhammad Yusof Ismail ◽  
Muhammad Ramlee Kamarudin
Keyword(s):  
Satellite Communication ◽  
Single Layer ◽  
Field Measurements ◽  
Scattering Parameter ◽  
Pin Diodes ◽  
Band Frequency ◽  
Frequency Tunability ◽  
Unit Cells ◽  
Phase Range ◽  
Beam Switching

This paper presents a practical demonstration for the design and development of a switchable planar reflectarray using PIN diodes in the X-band frequency range. Waveguide scattering parameter measurements for the unit cells and far-field measurements of the periodic reflectarrays have been carried out to verify the predicted results. Reflectarray unit cell measurements demonstrated a frequency tunability of 0.36 GHz with a dynamic phase range of 226°. On the other hand, the designed 6 × 6 periodic reflectarray has been shown to achieve beam switching from +6° to −6° with different switching states of PIN diodes. This type of beam switching can be used in satellite communication for specific region coverage.

scholarly journals Reconfigurable Reflectarray Antenna: A Comparison between Design Using PIN Diodes and Liquid Crystals

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Muhammad Inam Abbasi ◽  
Muhammad Yusof Ismail ◽  
Muhammad Ramlee Kamarudin ◽  
Qammer H. Abbasi
Keyword(s):  
Liquid Crystal ◽  
Frequency Tuning ◽  
Pin Diode ◽  
Scattering Parameter ◽  
Pin Diodes ◽  
Band Frequency ◽  
Dynamic Phase ◽  
Frequency Tunability ◽  
Phase Range ◽  
Reflectarray Antenna

This work presents the design and analysis of active reflectarray antennas with slot embedded patch element configurations within an X -band frequency range. Two active reflectarray design technologies have been proposed by digital frequency switching using PIN diodes and analogue frequency tuning using liquid crystal-based substrates. A waveguide simulator has been used to perform scattering parameter measurements in order to practically compare the performance of reflectarray designed based on the two active design technologies. PIN diode-based active reflectarray unit cell design is shown to offer a frequency tunability of 0.36 GHz with a dynamic phase range of 226°. On the other hand, liquid crystal-based design provided slightly lower frequency tunability of 0.20 GHz with a dynamic phase range of 124°. Moreover, the higher reflection loss and slow frequency tuning are demonstrated to be the disadvantages of liquid crystal-based designs as compared to PIN diode-based active reflectarray designs.

scholarly journals A Compact Single Layer Reflectarray Antenna Based on Circular Delay-Lines for X-band Applications

2018 ◽  
Vol 27 (2) ◽  
pp. 440-447 ◽  
Author(s):  
T. Shabbir ◽  
R. Saleem ◽  
S. U. Rehman ◽  
M. F. Shafique
Keyword(s):  
Single Layer ◽  
Delay Lines ◽  
X Band ◽  
Reflectarray Antenna

scholarly journals Design of A Perfect Metamaterial Absorber for Microwave Applications

2021 ◽  
Vol 22 (1) ◽  
pp. 1-4
Author(s):  
Khalid Al-Badri
Keyword(s):  
Normal Incidence ◽  
Metamaterial Absorber ◽  
Absorption Bands ◽  
Band Frequency ◽  
Image Sensing ◽  
Rectangular Patch ◽  
Low Profile ◽  
X Band ◽  
Unit Cells ◽  
Perfect Metamaterial Absorber

In this manuscript, a multi-band and low-profile metamaterial absorber with polarisation independence from 00 to 450 is presented. The proposed metamaterial structure is composed of a single ring with a rectangular patch, consisting of periodic unit cells with a size of 150mm × 250mm × 1.5mm. The structure exhibits three absorption peaks under normal incidence, which cover the X-band. According to the results, the desired material can excellently absorb the electromagnetic wave signal, with an outstanding absorption rate of about 95% at the microwave x-band frequency. The proposed structure shows three absorption bands where two of them exceed 90% absorption level. The results displayed a high Q-factor of 103.5 at a resonance frequency of 8.58 GHz and the figure of merit (FOM) is 98.4, which can be used to enhance the sensor sensing, narrowband band filter and image sensing. The proposed structure is fabricated, and experiments are carried out to validate the design principle. Strong agreements are observed between the measured and the corresponding simulated results.

scholarly journals Microwave Absorption Performance of Single-Layer and Multi-Layer Structures Prepared by CNTs/Fe3O4 Nonwoven Materials

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1000
Author(s):  
Rong Zhan ◽  
Jiaqiao Zhang ◽  
Qiang Gao ◽  
Qi Jia ◽  
Zhixiang Zhang ◽  
...  
Keyword(s):  
Reflection Loss ◽  
Single Layer ◽  
Frequency Range ◽  
Band Frequency ◽  
Layer Structures ◽  
X Band ◽  
Combination Scheme ◽  
Film Forming ◽  
Hot Rolled ◽  
Minimum Reflection Loss

Electromagnetic radiation can cause serious harm to the human body, such as the rise in body temperature and the decrease in immune function. In this study, the carbon nanotubes (CNTs)/Fe3O4 nonwovens were used to prepare wearable flexible absorbing materials. First, the single-layer absorbing structures were prepared by hot rolling, dipping, and film fabrication, respectively. Then, the single-layer structures were combined to form the multi-layer absorbing structures. By testing and analyzing the absorbing performance of various structures in the X-band frequency range, the optimum combination scheme was found, together with a good reflection loss value of CNTs/Fe3O4 nonwoven material. The experiment results displayed that the single-layer hot-rolled nonwovens modified by CNTs have the best wave absorbing performance. Its minimum reflection loss of −18.59 dB occurred at 10.55 GHz, and the efficient frequency occurred at 8.86–12.40 GHz. The modified film can significantly improve the absorbing performance of multi-layer structures. In addition, the absorbing performance was closely related to both the place where the absorbing film was introduced and the type of absorbing fillers. When the film-forming CNTs (FC) film was located at the bottom layer of the multi-layer structure, the hot rolled CNTs hot rolled mixed reagent film forming CNTs (HC-HM-FC) structure constructed exhibited the best absorbing effects. Its minimum reflection loss can reach −33 dB, and the effective absorbing frequency range covered half of the X-band.

scholarly journals Dual Layer Microstrip Refflectarray Composed of Two Stacked Arrays with Minkowski and Square Shaped Radiating Element

2012 ◽  
Vol 58 (1) ◽  
Author(s):  
M. F. Ismail ◽  
A. Wahid ◽  
M. K. A. Rahim ◽  
F. Zubir
Keyword(s):  
Single Layer ◽  
Side Lobe ◽  
Side Lobe Level ◽  
Variable Dimension ◽  
Reflection Phase ◽  
Radiating Element ◽  
Reflector Surface ◽  
Phase Range ◽  
Reflectarray Antenna ◽  
Lower Insertion Loss

A dual layer microstrip reflectarray composed of two stacked arrays with Minkowski and square patches of variable dimension is presented. The reflection phase coefficients on the reflector surface is achieved by tuning the dimensions of the patches. This technique is to broaden the bandwidth and to extend the reflection phase range compare to a conventional single layer reflectarray. From the simulation results of a unit cell composed of two stacked arrays of Minkowski and square patch showed that, 415° reflection phase range is achieved and lower insertion loss which is lower than 0.9 dB. Base on the simulated reflection phase coefficient, a dual layer microstrip reflectarray antenna with Minkowski and square radiating shape elements have been design and model using commercially available computer models of CST Microwave Studio. The reflectarray has been constructed using Taconic RF-35 substrate. From the radiation pattern at 11 GHz frequency, it shows that the HPBW of 4.7º in both plane, a side lobe level (SLL) of –17 dB and a maximum directivity of 26.1 dBi.

scholarly journals Broadband single-layer reflectarray antenna loaded with meander-delay-lines for X-band applications

2021 ◽  
Vol 60 (1) ◽  
pp. 1105-1112
Author(s):  
Tayyab Shabbir ◽  
Mohammad Tariqul Islam ◽  
Norbahiah Misran ◽  
Samir Salem Al-Bawri ◽  
Simranjit Singh
Keyword(s):  
Single Layer ◽  
Delay Lines ◽  
X Band ◽  
Reflectarray Antenna

scholarly journals A Novel Asymmetric Patch Reflectarray Antenna with Ground Ring Slots for 5G Communication Systems

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1450
Author(s):  
M. Hashim Dahri ◽  
M. Haizal Jamaluddin ◽  
Fauziahanim C. Seman ◽  
Muhammad Inam Abbasi ◽  
Adel Y. I. Ashyap ◽  
...  
Keyword(s):  
Communication Systems ◽  
Ground Plane ◽  
Single Layer ◽  
High Gain ◽  
Circular Ring ◽  
Vertical Side ◽  
Phase Range ◽  
Dual Resonance ◽  
Reflectarray Antenna ◽  
5G Communication

The narrow bandwidth and low gain performances of a reflectarray are generally improved at the cost of high design complexity, which is not a good sign for high-frequency operation. A dual resonance asymmetric patch reflectarray antenna with a single layer is proposed in this work for 5G communication at 26 GHz. The asymmetric patch is developed from a square patch by tilting its one vertical side by a carefully optimized inclination angle. A progressive phase range of 650° is acquired by embedding a circular ring slot in the ground plane of the proposed element for gain improvement. A 332-element, center feed reflectarray is designed and tested, where its high cross polarization is suppressed by mirroring the orientation of asymmetric patches on its surface. The asymmetric patch reflectarray offers a 3 dB gain bandwidth of 3 GHz, which is 4.6% wider than the square patch reflectarray. A maximum measured gain of 24.4 dB has been achieved with an additional feature of dual linear polarization. Simple design with wide bandwidth and high-gain of asymmetric patch reflectarray make it suitable to be used in 5G communications at high frequencies.

Electromagnetic shielding performance of copper and silver-plated hybrid yarn based multilayer fabrics in C & X band frequency range

2021 ◽  
pp. 152808372199936
Author(s):  
Dharmendra Nath Pandey ◽  
Arindam Basu ◽  
Pramod Kumar
Keyword(s):  
Single Layer ◽  
Woven Fabrics ◽  
Electromagnetic Shielding ◽  
Wave Polarization ◽  
Frequency Range ◽  
Band Frequency ◽  
Hybrid Yarn ◽  
Triple Layer ◽  
X Band ◽  
Layer Composition

In the present study, a strategic designing of multilayer shield was planned to enhance the multiple reflection phenomenon to achieve maximum absorption properties in microwave frequency (C & X band) range. Multi-layer EMR shields were developed using pure cotton fabric and conductive woven fabrics, incorporated with copper- based & silver-plated hybrid yarn. First of all, single layer fabrics were produced in five variants, nomenclature as L1A (pure cotton) L1B, L1C (copper-based hybrid yarn), LS1B and LS1C (silver plated hybrid yarn). These five variants were used to prepare four sets of double & triple layer fabric. In both double and triple layer composition, L1A fabric (pure cotton) was used as top layer followed by B and C series fabrics, containing copper and silver-plated hybrid yarn. The EMSE performance in C and X band frequency range of single layer, double layer and triple layers in terms of scattering parameters S11(reflectance) & S21 (transmittance) in vertical and horizontal wave polarization was studied. It was found that number of layers, layer composition, orientation of metallic yarn, frequency and EM wave polarization have significant influence on overall electromagnetic shielding effectiveness.

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