Dual Band Research Articles

Design of Slotted Patch MIMO Antenna and Investigation of Antenna Parameters for Sub-6 5G Network

A "Multiple-input-multiple-output (MIMO)" antenna with dual band features is presented herein research work and is taken into consideration for the unlicensed National Information Infrastructure radio band (n77, n78, and n46). Simple single-patch MIMO antennas give way to two-element MIMO antennas through a gradual development process. Using circular slots on the main patches, two Microstrip antennas are integrated. The development of numerous band features also makes use of reduced ground. In order to attain excellent isolation, Rectangular Metallic Strip (RMS) is used. Given that it covers two important frequency bands, the proposed MIMO antenna offers a considerable advantage. With a 2.18 GHz total bandwidth, the antenna system resonates at 3.26 GHz and 5.4 GHz. A 1.6 mm thick FR4 substrate was used in the antenna's design. A 8.2 mm feed line with an inset feed is employed, and a specifically designed SMA connector with perfect electrical conductor (PEC) and Teflon is used for simulation purposes in order to enhance impedance matching. Radiation properties such as mean effective gain, envelope correction coefficient, reflection coefficient, and others are investigated and researched. Less than -10 dB is the value of both the isolation and the reflection coefficient, with the former being less than -30 dB. Having this two-element, smaller MIMO antenna is very beneficial for 5G applications.

A Comprehensive Analysis of Low-Profile Dual Band Flexible Omnidirectional Wearable Antenna for WBAN Applications

A Comprehensive Analysis of Low-Profile Dual Band Flexible Omnidirectional Wearable Antenna for WBAN Applications

Двошаровий Т-подібний навантажений шпильковий резонатор для двоcмугового смугопропускного фільтра з покращеними параметрами

В статті розроблено простий високоефективний компактний двосмуговий фільтр на основі багатошарового Т-подібного навантаженого шпилькового резонатора T-SLHR (T-shape loaded hairpin resonator). В схемі розробленого фільтра використано дві підкладки. На заземленій площині першої підкладки реалізовані два резонатори T-SLHR, які електрично зв’язані через просторовий зазор S, завдяки чому досягається необхідна подвійна смуга пропускання. На другій незаземленій підкладці розташовується заземлений шпильковий шлейф, вхід/вихід якого з’єднується з T-SLHR для отримання необхідної характеристики фільтра. Для перевірки запропонованої концепції реалізовано двосмуговий смуго-пропускний фільтр BPF (bandpass filter) для системи багатоканальної бездротової мережі, що працює на центральних частотах 2,4 ГГц і 3,5 ГГц. Крім того, на основі теорії непарних і парних мод аналізується можливість генерації заданих частот за допомогою T-SLHR. Також, представлена блок-схема за допомогою якої пояснюється механізм зв’язку та очікувані характеристики фільтра. Крім того, змодельований фільтр був виготовлений, і отримані результати вимірювань і моделювання порівняні та проаналізовані. Виготовлений фільтр має досить малу площу менше 126 мм2, високу вибірковість завдяки високій крутизні скатів характеристики фільтра та високий рівень смуг загородження.

Simulation based Comparative Review on a Metasurface based Perfect Absorber

In this paper, the different research papers are studied and comparatively analyzed to carry out the simulation based survey of various proposals for improvement to design Metarsurface based Perfect Absorber for GHz and THz frequency band for RF Energy Harvesting applications. Using a structure that can effectively absorb the most radiation is one of the biggest obstacles in reducing the impact of EM wave radiation. A perfect absorber may be created using variety of structures and materials with various specifications. Various structures are designed and simulated by different authors in variety of simulation softwares using useful parameters. Three distinct structures have been created, two of which were created using CST Microwave Studio and the third using HFFS for comparative study. A perfect absorber can be constructed for GHz and THz for dual band and multiband since the operating frequency range and band are not limited.

Design of Flexible and Dual Band Antenna for Vehicular Communication

The antenna with bowtie and meander lines shaped elements for the vehicular communication in this paper. The dimensions of the proposed antenna are 40.5*91.5*0.1. The substrate used in this antenna is polyamide substrate with a permittivity of 4.3. The implemented antenna is operated at cellular (975MHz) and C-V2X (5.9GHz) band. The efficiency of this proposed antenna is 99.5%. This paper describes the design of antenna with high efficiency vehicular roof mounted for V2V communication system used for ubiquitous intelligent systems. To enhance the connectivity among vehicles by providing seamless communication and to reduce initial access time using high performance antenna systems is the purpose of the ubiquitous intelligent systems. V2V communication efficiency depends on the antenna efficiency used for ubiquitous intelligent systems. We are proposing this antenna to increase the performance of the antenna by enhancing efficiency.

Asymmetric Coplanar Strip- (ACS-) Fed Side Edge Panel MIMO Antenna for IoT and 5G Applications

For future wireless high-speed wireless applications, the antenna design plays an indispensable role. Electrical compactness has been challenging over the years among the research fraternity. Hence, this paper proposes an electrically compact and miniaturized asymmetric coplanar strip- (ACS-) fed MIMO to bridge this research gap. In MIMO antennas, two electrically small antennas are used and are placed on the edges of the smartphone. A ladder-shaped radiator with a C-shaped slit inserted on the ground plane makes up the antenna’s monopole radiator. A compact antenna is proposed in this paper with dimensions of 0.076 λ×0.409 λ×0.005 λ. This achieves dual band characteristics, which cater to 3.5/5.5 GHz (WiMAX), 5.8 GHz (WLAN), 6.3 GHz (C-band), and sub-6 GHz 5G bands. For the available aperture, reasonable gain is attained by the proposed architecture. Furthermore, fractional bandwidth of 69% and 43% in 2.6 GHz and 5.5 GHz bands, respectively, acting in accordance with the bandwidth stated by Wheeler and Chu’s limit, has been attained in this ACS-fed antenna. In both the operating frequency bands, more than 20 dB isolation between the antenna elements has been achieved. High integrity is attained by the radiation pattern, and actual deployment is granted. Moreover, the simulated results presented are in good accordance with the measured results.

A twelve element dual-band MIMO antenna for 5G smartphones.

In this paper, a 12x12 dual-band MIMO antenna for 5G smartphones is proposed. It operates in the sub 6 GHz (2.4GHz and 3.5GHz) frequency bands. The MIMO antenna elements are printed on an FR4 epoxy substrate that has a thickness of 0.8mm. The main substrate measures 150 × 75 × 0.8 mm3, while the side substrates have dimensions of 75 × 6 × 0.8mm3. The twelve dual-band antenna elements are compact in size. Each antenna element size is reduced significantly, which is 11.20 × 5.98 mm2(0.0896λ × 0.04784λ). These antenna elments are arranged in such a way that the MIMO antenna not only provides polarization diversity but also helps in achieving good performance in terms of isolation, which is more than 13.5 dB between two adjacent antenna elements. Another significance of the proposed antenna is that both the frequency bands can be tuned independently by varying the corresponding length of each arm. The performance parameters like efficiency is around 40-56% for the lower band and it is 48-62% for the upper band. The envelope correlation coefficient (ECC) is below 0.04 in both frequency bands for the proposed dual band MIMO antenna.

Design and optimization of a deep learning algorithm assisted stub-loaded dual band four-port MIMO antenna for Sub-6 GHz 5G and X band satellite communication applications

In this article, C-type stubs loaded hexagonal shaped four-element MIMO antenna is proposed with improved isolation for sub-6 GHz 5G and X-band satellite wireless communication applications. Initially, the design and simulation studies of the MIMO antenna are performed using Computer Simulation Software (CST) software but its design parameter estimation and optimization consume higher time using conventional EM simulation tools. In order to solve this issue, Deep Learning algorithm-based approach has been proposed to determine the optimal physical parameters along with best possible performance characteristics. This suggested DL based approach is resource and time efficient for parameter estimation and optimization during the design process. To reduce design space and generation of an effective dataset, the feature reduction method (FRM) is implied during the design process. The S-parameters are predicted through Dual-Channel (DC-DNN) Deep Neural Network model. The dual-band MIMO antenna operates with −10 dB impedance Bandwidths of 40 % (2.8 GHz – 4.2 GHz), 38.41 % (6.1 GHz – 9.0 GHz) and shows excellent diversity performance. The proposed MIMO antenna is suitable for Sub-6 GHz n77 (3.3–4.2 GHz), n78 (3.3–3.8 GHz) 5G NR bands and also supports X band satellite (7.25–7.75 GHz and 7.9–8.4 GHz) communication applications.

Stable WO3 electrochromic system based on NH4+ hydrogen bond chemistry

As the best-known and extensively-studied electrochromic material, tungsten trioxide (WO3) has drawn tremendous interest due to its low material cost, environmental benignity, dual band regulation, high optical modulation, and high chemical stability. However, these films always suffer from ion-trapping-induced degradation in electrochromic performance when cycled in alkali cation (such as Li+, Na+, K+, etc.) electrolytes. Herein, we report a stable WO3 electrochromic system enabled by a NH4CF3SO3-TEP (Triethyl phosphate) organic electrolyte. Based on comparative experiments and systematic characterizations, the prolonged cycling stability is mainly attributed to the formation of hydrogen bonds between the NH4+ ions and the WO3 lattice, which are much weaker than metallic coordination bonds. Furthermore, the bulky CF3SO3− anion and large TEP solvent molecule are also favorable to stabilize WO3, since they are more resistive to be co-inserted into the WO3 lattice along with the shuttling NH4+ cations. Thanks to these merits, this NH4CF3SO3-TEP electrolyte simultaneously enables great electrochromic activity (76.1 % transmittance modulating ability at 633 nm) and impressive cyclic color-switching stability (1000 times color change without any detectable electrochromic performance or mechanical degradation), overwhelmingly outperforming the conventional Li+/K+ electrolytes. Furthermore, as a demonstration of its application, a WO3/Zn electrochromic device is fabricated based on a NH4+/Zn2+-CF3SO3 dual-cation TEP electrolyte. These findings may shed light on the in-depth understanding of WO3′s “ion trapping” effect, as well as the electrolyte design of high-performance WO3-based electrochromic devices.

Erratum to A dual band compact circularly polarized antenna for GPS applications

Erratum to A dual band compact circularly polarized antenna for GPS applications

E-Plane dual band bandstop waveguide filter for possible X-band applications

ABSTRACT This paper presents, a novel second order E-plane planar insert based dual band bandstop waveguide filter. The circular shape with two T-shape resonators are printed on Roger RO4350 dielectric substrate to form planar insert. The insert are placed in such a way that positioned in E-plane of the standard WR-90 rectangular waveguide. The independent resonant frequency and bandwidth of the stopband can be adjusted by tuning the resonators. To achieve second order dual band bandstop filter response four asymmetrical circular shape with two T-shape resonators are designed on dielectric substrate to form different stopbands and separated by some specific distance to eliminate the unwanted coupling between them. The numerical analysis of the proposed filter is carried out using CST microwave studio. To validate the numerical analysis of the proposed filter, resonator, WR-90 rectangular waveguide is fabricated and measured. The measured results shows stopband characteristics having centre frequencies f 01g = 8.56 GHz and f 02 = 11.21 GHz and exhibits the bandwidth of 0.4146 GHz and 0.3824 GHz. The simulated and measured result are in good agreement.

Cost-Effective Design of Polarization and Bandwidth Reconfigurable Millimeter-Wave Loop Antenna.

A singly fed reconfigurable circular loop antenna is proposed for millimeter-wave (mmWave) communication systems. This antenna's distinctive feature lies in its capacity to adjust both polarization and bandwidth characteristics, a capability made possible by the strategic integration of two PIN diodes. These diodes are engineered to function in various modes, allowing for three distinct polarization states and accommodating two distinct bandwidths. A meticulous alignment of these PIN diodes enables the utilization of a single DC bias network as a highly effective RF choke, which simplifies the design and reduces the associated losses. Additionally, a planar biasing network that consists of coplanar strip-lines (CPS) has been employed eliminating the need for lumped elements. The simple and totally planar configuration offers a choice of right-hand circularly polarized (RHCP) radiation or left-hand circularly polarized (LHCP) radiation at 28 GHz. This is accompanied by impedance matching and axial ratio (AR) bandwidths of 12.9% and 8%, respectively, over the same frequency range with a gain of 7.5 dBic. Moreover, when the PIN diodes are unbiased, the antenna offers linear polarization (LP) over two narrow bandwidths at 27 GHz and 29 GHz featuring a maximum gain of 7.2 dBic. Therefore, the proposed configuration offers three operating modes: wide-band RHCP, wide-band-LHCP, and LP over dual narrow bands. Significantly, simulated results closely align with the measured outcomes, affirming the robustness and accuracy of this design.

Formation of Dual Bands in Mixed-Halide Perovskites During Photoinduced Halide Segregation

Formation of Dual Bands in Mixed-Halide Perovskites During Photoinduced Halide Segregation

A Dual Band 28/38 GHz Metamaterial Absorber for 5G Applications

A dual-band metamaterial absorber (MMA) for fifth-generation (5G) applications is discussed in this work. The suggested absorber works at frequency bands of 28 GHz and 38 GHz. The suggested MMA unit cell with a size of 5.8 mm × 5.8 mm (0.54 λ0 × 0.54 λ0 at 28 GHz) is designed on 1.5 mm (0.14 λ0) low-cost FR4 substrate and composed of two metallic ring resonators. The suggested MMA is investigated to validate its performance for different polarization for transverse electric (TE) and transverse magnetic (TM). Both normal and oblique angles are studied. The MMA has a simple structure with a compact size. Different parameters such as the currents, electric field distributions, and normalized impedance are studied. The array of 10 × 10 unit cells is utilized to verify the simulated outcomes. The suggested MMA is fabricated and tested, and its outcomes are compared to the simulated outcomes. The MMA is operated at dual bands 28/38 GHz with high absorption rates of 98 and 98.4%, respectively, under the normal incidence for both outcomes. A good matching between the two outcomes is observed, which supports the MMA for 5G applications.

Dual Band Coaxial Y-Monopole for Hyperthermia Treatment of Cervical Cancer Delivered Through an Intrauterine Tandem

Dual Band Coaxial Y-Monopole for Hyperthermia Treatment of Cervical Cancer Delivered Through an Intrauterine Tandem

Optically transparent dual-band antenna for UHF and S-band applications

This paper presents a novel optically transparent antenna that utilizes Indium Tin Oxide-coated Polyethylene Terephthalate (ITO-PET) and Soda-lime-glass (SLG) substrate. It explores ITO-PET and SLG for transparent antenna fabrication, thoroughly evaluating the antenna’s performance in relation to ITO-PET’s conductivity. Operating in dual bands (1.6–2 GHz UHF and 3.25–4.95 GHz S-band), the antenna’s inventive design features a slotted circular structure with a modified ground plane, crucial for achieving dual-band functionality. Despite ITO-PET’s relatively low conductivity, the antenna outperforms expectations, exhibiting a wider bandwidth in the higher band and positive gain in both bands, conforming the potential of ITO-PET. The successful realization of this innovative concept is validated through the fabrication and measurement of the antenna prototype, signaling a new frontier in transparent antenna technology.

Direct White-Light Emitting From a Single Metal-Organic Framework with Dual Phosphorescence Peaks.

Single component white-light-emitting (SCWLE) materials are extremely desired in the field of solid-state lighting. However, pure-phosphorescent SCWLE has rarely been reported. Herein, one halogen-bonding-containing MOF [Cd(5-BIPA)(phen)] (1) has been synthesized, which shows efficient white-light emission originating from dual phosphorescence bands with different wavelengths and lifetimes. The fabrication of a phosphor-converted white-light-emitting diode device driven by pulsing current enables this MOF to be a promising phosphor.

Antimony-Triggered Tunable White Light Emission in Lead-Free Zero-Dimensional Indium Halide with Ultrastable CCT of White Light Emitting Diodes.

A highly efficient and easily tunable luminescence is significant for solid-state luminescent (SSL) materials. However, achieving a photoluminescence quantum yield (PLQY) close to unity and tuning the emission remain challenging tasks. Metal doping strategies enable resolution of these issues. Herein, we report the preparation of a novel organic-inorganic lead-free indium-based metal halide hybrid (MP)3InCl6•EtOH (MP = C4H10ON) with a typical zero-dimension structure. When excited at 320 nm, (MP)3InCl6•EtOH exhibits a dual emission band at 420 and 600 nm, which originates from the organic cation [MP] and the [InCl6]3- octahedral unit. The photoluminescence can be significantly enhanced through Sb3+ doping, resulting in an increase in PLQY from 0.78% to near unity. Multiple emission color tunings have been achieved by regulating the Sb doping level and the radiation wavelength, resulting in a change in emission color from blue → white → orange. Optical characterizations reveal that the significantly enhanced emission centered at 600 nm can be attributed to more efficient absorption, closely associated with an additional 1S0 → 3P1 transition in the inorganic octahedron [In(Sb)Cl6]3- due to Sb3+ doping. With its excellent optical performance, a white light emitting diode (WLED) has been successfully fabricated by coating the mixture of (MP)3InCl6•EtOH:15%Sb3+ with blue phosphor BaMgAl10O17:Eu2+ onto a UV LED chip. The WLED device exhibits perfect white light emission with regard to the International Commission on Illumination (CIE) coordinates of (0.36, 0.34). Significantly, the WLED device maintains a stable correlated color temperature (CCT) range of 4119-4393 K and CIE coordinates (x: 0.37-0.34, y: 0.35-0.33) as the driven current varies from 20 to 200 mA, demonstrating outstanding stability across different power levels. This work not only presents a novel system for achieving remarkably enhanced luminescent performance and tuning emission bands in 0D metal halides but also represents a significant step toward achieving resistance to color drifting for stable WLEDs.

Design of Multiband, Reconfigurable Coplanar Meander Antenna for WLAN Applications

This paper presents the implementation of Reconfigurable, Planar Meander Antenna operates at 2.45 GHz and 5.12 GHz for WLAN applications. In the proposed work the planar meander antenna is designed using FR4 substrate. In the meander antenna the varactor diodes are incorporated in the appropriate arm positions to achieve reconfigurability. In this, reconfigurability is accomplished using frequency tuning. Also, the principle of reconfigurability in meander antenna focuses size reduction and dual band operations. The meander structure is characterized for its operating frequency. A parametric study is done for finding the resonance in the appropriate arm positions of the meander antenna. The varactor diodes fixed meander antenna is tested using network analyzer. The comparison is made for the antenna designs of with and without varactor diodes for the establishment of reconfigurability. The effects of active components are ignored. The proposed antenna design is validated for its concurrence in both simulation and experimentation. The arm and the behavior of the frequency tuning is tested using the network analyzer. The reflection coefficient is -23.66dB and -18.41dB at 2.45 GHz and 5.1 GHz respectively. The overall size of the meander antenna is reduced by 76%. VSWR of the proposed antenna is 1.

Simplified compact 4 element MIMO loop antenna structure with decoupling set-up and dual band for 5G wireless terminal devices

Simplified compact 4 element MIMO loop antenna structure with decoupling set-up and dual band for 5G wireless terminal devices