scholarly journals Design of Wideband Absorber Based on Dual-Resistor-Loaded Metallic Strips

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Mingxi Zhang ◽  
Binchao Zhang ◽  
Xiaochun Liu ◽  
Shining Sun ◽  
Cheng Jin
Keyword(s):  
Physical Mechanism ◽  
Equivalent Circuit Model ◽  
Normal Incidence ◽  
Dielectric Substrate ◽  
Fractional Bandwidth ◽  
Resonant Frequencies ◽  
Conducting Plate ◽  
Low Profile ◽  
Resistive Sheet ◽  
Absorption Performance

A method for designing a dual-polarized wideband absorber with low profile by using dual-resistor-loaded metallic strips is proposed in this paper. Each unit cell consists of a resistive sheet with dual-resistor-loaded metallic strips and an underlying conducting plate. Two-dimensional arrays of two unequal metallic strips are printed on the dielectric substrate, and two resistors are embedded in the metallic strips. By properly designing the resonant frequencies of these metallic strips, a wide absorption band with three resonances is obtained. An equivalent circuit model is introduced, and the current distributions are examined to understand the physical mechanism of the proposed absorber. An example of the absorber is fabricated and measured to verify our designed concept. The measured results show that the wideband absorption performance with a fractional bandwidth of 129% under the normal incidence and the stable angular response are achieved. In addition, the proposed absorber has a low profile with 0.08λL, where λL is the wavelength at the lowest operating frequency.

scholarly journals Novel Frequency-Selective Rasorber with Ultrawide Absorption Bandwidth Covering Both the X- and Ku-Bands

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1449
Author(s):  
Jie Xiong ◽  
Yanjie Wu ◽  
Yu Mao ◽  
Feng Deng ◽  
Lijie Chen ◽  
...  
Keyword(s):  
Absorption Band ◽  
Equivalent Circuit Model ◽  
Normal Incidence ◽  
Strip Line ◽  
Total Thickness ◽  
Absorption Bandwidth ◽  
Low Profile ◽  
Frequency Selective ◽  
Profile Characteristics ◽  
Transmission Layer

A novel dual-polarized transmissive/absorptive frequency-selective rasorber (FSR) with an ultrawide absorption spectrum covering both the X- and Ku-bands is proposed in this paper. The FSR is constructed from a bottom lossless transmission layer and a top lossy absorption layer, in which a resistor-loaded incurved square loop strip line structure is utilized to obtain an ultrawide absorption band. To quantitatively analyze its operation principle, an accurate equivalent circuit model of the proposed FSR was developed. A 2D prototype was designed, assembled, fabricated, and measured. The FSR exhibits an absorption band that ranges from 8.1 to 19.1 GHz (81%) under normal incidence, whereas the passband insertion loss at 4.5 GHz is less than 0.45 dB. The total thickness of the FSR is only 5.1 mm, which keeps low profile characteristics. The simulation agrees well with the measured results.

scholarly journals Design and Analysis of Super Wideband Antenna for Microwave Applications

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 477
Author(s):  
Warsha Balani ◽  
Mrinal Sarvagya ◽  
Ajit Samasgikar ◽  
Tanweer Ali ◽  
Pradeep Kumar
Keyword(s):  
Communication Systems ◽  
Equivalent Circuit Model ◽  
Wireless Communication Systems ◽  
Impedance Bandwidth ◽  
Frequency Range ◽  
Fractional Bandwidth ◽  
Wide Bandwidth ◽  
Wireless Applications ◽  
Frequency Constraint ◽  
Time Domain Characterization

In this article, a compact concentric structured monopole patch antenna for super wideband (SWB) application is proposed and investigated. The essential characteristics of the designed antenna are: (i) to attain super-wide bandwidth characteristics, the proposed antenna is emerged from a traditional circular monopole antenna and has obtained an impedance bandwidth of 38.9:1 (ii) another important characteristic of the presented antenna is its larger bandwidth dimension ratio (BDR) value of 6596 that is accomplished by augmenting the electrical length of the patch. The electrical dimension of the proposed antenna is 0.18λ×0.16λ (λ corresponds to the lower end operating frequency). The designed antenna achieves a frequency range from 1.22 to 47.5 GHz with a fractional bandwidth of 190% and exhibiting S11 < −10 dB in simulation. For validating the simulated outcomes, the antenna model is fabricated and measured. Good conformity is established between measured and simulated results. Measured frequency ranges from 1.25 to 40 GHz with a fractional bandwidth of 188%, BDR of 6523 and S11 < −10 dB. Even though the presented antenna operates properly over the frequency range from 1.22 to 47.5 GHz, the results of the experiment are measured till 40 GHz because of the high-frequency constraint of the existing Vector Network Analyzer (VNA). The designed SWB antenna has the benefit of good gain, concise dimension, and wide bandwidth above the formerly reported antenna structures. Simulated gain varies from 0.5 to 10.3 dBi and measured gain varies from 0.2 to 9.7 dBi. Frequency domain, as well as time-domain characterization, has been realized to guide the relevance of the proposed antenna in SWB wireless applications. Furthermore, an equivalent circuit model of the proposed antenna is developed, and the response of the circuit is obtained. The presented antenna can be employed in L, S, C, X, Ka, K, Ku, and Q band wireless communication systems.

Sound absorption performance of flexible polyurethane/silicon dioxide perforated coating composites

2021 ◽  
pp. 004051752110155
Author(s):  
Min Peng ◽  
Xiaoming Zhao ◽  
Weibin Li
Keyword(s):  
Silicon Dioxide ◽  
Sound Absorption ◽  
Woven Fabric ◽  
Perforation Rate ◽  
Cavity Depth ◽  
Resonant Frequencies ◽  
The Matrix ◽  
Absorption Performance ◽  
Traditional Sense ◽  
Flexible Polyurethane

Perforated materials in the traditional sense are rigid, usually dense, costly and inflexible. For this study, polyester/cotton blended woven fabric as the base fabric, nano-SiO2 (silicon dioxide) as the functional particles and PU (polyurethane) as the matrix were selected. Accordingly, flexible PU/SiO2 perforated coating composites with different process parameters were developed. The influence of the nano-SiO2 content, perforation diameter, perforation rate, number of fiber felt layers and cavity depth on the sound absorption coefficient were investigated. The resonant frequencies of materials with different cavity depths were evaluated by both theoretical calculation and experimental method. It was found that the flexible perforated composite has good sound absorption and mechanical properties, and has great potential for applications requiring soft and lightweight sound absorption materials.

Miniaturized frequency selective surface with high angular stability

Frequenz ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Zain Ul Abidin ◽  
Qunsheng Cao ◽  
Gulab Shah ◽  
Zaheer Ahmed Dayo ◽  
Muhammad Ejaz
Keyword(s):  
Resonant Frequency ◽  
Electric Field Distribution ◽  
Equivalent Circuit Model ◽  
Surface Current ◽  
Frequency Selective Surface ◽  
Angular Stability ◽  
Working Mechanism ◽  
Low Profile ◽  
Simple Geometry ◽  
Frequency Selective

Abstract In this paper, a miniaturized bandstop frequency selective surface (FSS) with high angular stability is presented. Each FSS element consists of four sets each consisting eight octagonal concentric interconnected loops. The four sets are connected with each other through outermost octagonal loop. The unit size is miniaturized to 0.066 λ0 at the resonant frequency of 1.79 GHz. The proposed configuration achieves excellent angular stability (only 0.025 GHz resonant frequency deviation is observed upto 83° oblique angles). The working mechanism of FSS is explained with the help of equivalent circuit model (ECM), electric field distribution, and corresponding surface current distribution. A prototype of the designed bandstop FSS is fabricated to verify the simulated frequency response. The experimental results are consistent with the simulation results. Simple geometry, low profile, high angular stability, and compact cell size are prominent features of the proposed structure.

A Wideband Bandpass Filter Integrated Single-Pole Double-Throw Switch with Wide Stopband

Frequenz ◽  
2018 ◽  
Vol 72 (11-12) ◽  
pp. 533-537 ◽  
Author(s):  
Jin Xu ◽  
Qi-Hang Cai ◽  
Zhi-Yu Chen
Keyword(s):  
Insertion Loss ◽  
Bandpass Filter ◽  
Fractional Bandwidth ◽  
Central Frequency ◽  
Resonant Frequencies ◽  
Capacitively Coupled ◽  
Filter Theory ◽  
Compact Size ◽  
Better Than ◽  
Coupled Resonator

Abstract This paper proposes a wideband bandpass filter (BPF) integrated single-pole double-throw (SPDT) switch by using the capacitively coupled LC resonators with loaded p-i-n diodes. The BPF-integrated on-state channel can be synthesized by using the coupled resonator filter theory, and the off-state channel with high suppression is built due to the misaligned resonant frequencies of LC resonators. As an example, a BPF-integrated SPDT switch is designed and fabricated with the central frequency of 1 GHz and the 3 dB fractional bandwidth of 29.7 %. The on-state channel has a measured insertion loss of 1.23 dB, and a 20 dB rejection wide stopband from 1.47 GHz to 8.6 GHz. The off state channel has a 43 dB suppression around 1 GHz. The isolation between two ports is better than 52.4 dB. The fabricated BPF-integrated SPDT switch size including bias circuits but excluding feeding lines has a compact size of 0.086 λg×0.096 λg.

scholarly journals Millimeter Wave Fabry-Perot Resonator Antenna Fed by CPW with High Gain and Broadband

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Xue-Xia Yang ◽  
Guan-Nan Tan ◽  
Bing Han ◽  
Hai-Gao Xue
Keyword(s):  
Millimeter Wave ◽  
Coplanar Waveguide ◽  
Dielectric Substrate ◽  
High Gain ◽  
Center Frequency ◽  
Impedance Bandwidth ◽  
Gain Bandwidth ◽  
Broad Bandwidth ◽  
Low Profile ◽  
Fabry Perot

A novel millimeter wave coplanar waveguide (CPW) fed Fabry-Perot (F-P) antenna with high gain, broad bandwidth, and low profile is reported. The partially reflective surface (PRS) and the ground form the F-P resonator cavity, which is filled with the same dielectric substrate. A dual rhombic slot loop on the ground acts as the primary feeding antenna, which is fed by the CPW and has broad bandwidth. In order to improve the antenna gain, metal vias are inserted surrounding the F-P cavity. A CPW-to-microstrip transition is designed to measure the performances of the antenna and extend the applications. The measured impedance bandwidth ofS11less than −10 dB is from 34 to 37.7 GHz (10.5%), and the gain is 15.4 dBi at the center frequency of 35 GHz with a 3 dB gain bandwidth of 7.1%. This performance of the antenna shows a tradeoff among gain, bandwidth, and profile.

Investigation of a Compound Perforated Panel Absorber With Backing Cavities Partially Filled With Polymer Materials

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
C. Q. Wang ◽  
Y. S. Choy
Keyword(s):  
Sound Absorption ◽  
Normal Incidence ◽  
Polyester Fiber ◽  
Polymer Materials ◽  
Element Simulation ◽  
Parallel Arrangement ◽  
Cavity Configuration ◽  
Absorption Performance ◽  
Good Agreement ◽  
Panel Absorber

The paper concerns the sound absorption performance of a compound absorber which consists of a parallel arrangement of multiple perforated panel absorbers of different backing cavity depths partially filled with poroelastic polymer materials. Three polymer materials are considered: expandable polystyrene (EPS) foam, polymethacrylimide (PMI) foam, and polyester fiber. The normal incidence sound absorption coefficients of the compound panel absorber are tested experimentally. Results show that the former two foams can achieve similar absorption performance to the rigid cavity configuration, while the resonances shift to lower frequencies due to the changes of effective cavity depths. It is also found that the additional attenuation by polymer foams may improve sound absorption, but the effect is marginal. For polyester fiber, results show that it performs more like a single perforated panel absorber. Finite element simulation of the compound panel absorber is also discussed, and good agreement is observed between simulated and experimental results.

Design and implementation of 2.5D frequency-selective surface based on substrate-integrated waveguide technology

2019 ◽  
Vol 11 (3) ◽  
pp. 255-267 ◽  
Author(s):  
Krushna Kanth Varikuntla ◽  
Raghavan Singaravelu
Keyword(s):  
Incidence Angle ◽  
Equivalent Circuit Model ◽  
Frequency Selective Surface ◽  
Dielectric Substrate ◽  
Angular Stability ◽  
Substrate Integrated Waveguide ◽  
Patch Type ◽  
Angular Performance ◽  
Final Design ◽  
Frequency Selective

AbstractIn this paper, the patch-type frequency selective surfaces (FSS) based on substrate-integrated waveguide (SIW) technology is proposed to improve the bandwidth (BW) and angular performance. The proposed FSS configuration overcomes the limitations of both conventional 2D and 3D FSS structures. A closely coupled cascaded mechanism is employed to combine two identical FSS elements separated by thin dielectric substrate results in incorporation of SIW technology; hence, named as 2.5D FSS. A derived equivalent circuit model is used to estimate the basic performance of proposed FSS–SIW elements, and the response of analytical expressions has been validated and final design is obtained using full-wave simulations. Two basic FSS elements viz. single square loop and a Jerusalem cross have been investigated to prove the enhancement in their BW and angular stability. The proposed technique evidently improves the BW and angular stability of FSS structures than in its established form. Besides, various important parameters that influence the performance characteristics of reported 2.5D FSSs are also studied. The important observations made on the thickness, as the thickness increases the bandstop FSS, can change to bandpass FSS. Finally, the proposed FSS structure has been fabricated and measured using free space measurement setup, to show the effectiveness of theoretical results. The measured results show good agreement with simulated results at normal and oblique incidence angle.

Design and Development of Low-Profile Multi-Band Antenna Fed by SIW Cavity Resonator Using Twin Apertures

Frequenz ◽  
2019 ◽  
Vol 73 (7-8) ◽  
pp. 235-243
Author(s):  
Meenakshi Sharma ◽  
Manish Zadoo ◽  
Ashwani Kumar ◽  
Pramod Kumar ◽  
Shailendra Singh
Keyword(s):  
Secure Communication ◽  
Cavity Resonator ◽  
Band Spectrum ◽  
Resonant Frequencies ◽  
Low Profile ◽  
Data Rates ◽  
X Band ◽  
Linearly Polarized ◽  
Novel Design ◽  
Multi Band

Abstract A novel design of compact, linearly polarized and low-profile planar antenna which is electrified by Substrate Integrated Waveguide (SIW) resonator has been developed for multi-band applications of X-band spectrum. Radiating patch has been excited through two closely spaced longitudinal apertures of identical length but non-identical width, incorporated in SIW resonator. These apertures are responsible for multiple operating bands. The achieved fractional bandwidths are 1.29 %, 0.49 % and 1.60 % having resonant frequencies at 10.07 GHz, 10.85 GHz and 11.82 GHz respectively for |S11| ≤ -10 dB. The measured peak gain for first, second and third operating band is 6.54 dB, 6.86 dB and 7.68 dB respectively. The proposed antenna is a highly selective antenna for various applications of X-band microwave spectrum. This band has been particularly selected for military communication because it provides a trade-off between the characteristics (i. e. interference and rain resilience, data rates and remote coverage) of different frequency bands which are particularly suited to the needs of military users. It is very much suitable for secure communication i. e. to deny unauthorized access to sensitive unclassified information and prevent disruption of telecommunication. A comparative analysis of antenna’s parameters has been examined by Ansys HFSS and results are verified through experimental outcomes.

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