Multiband Design Research Articles

Design and performance observation of U-shapedQuadpot multiband operated MIMO antenna structure for 5G and WLAN applications using FR4 substrate with high isolation

The multiband operated four port MIMO antenna structure is presented in the manuscript. The unique U-shaped radiating patch element is considered for the analysis. Multiple iterations are taken to finalize the shape of the best structure. The DGS and parasitic patch approach helps enhance MIMO antenna performance. Four parametric studies are performed to find the best structure, varying the patch's length, breadth, parasitic patch radius and DGS. The analysis of scattering response is considered to be over 1 GHz to 14 GHz for the observation of band response. The suggested design represents a reflection coefficient of −38.092 dB and a peak bandwidth of 5.78 GHz. The proposed design provides a peak isolation of 60 dB and a peak E-field of 1.80 × 104 V/m. Using an FR4 substrate, the structure's response is compared with the simulated and measured. The effectiveness of the MIMO structure is checked by observing the performance of diversity parameters. The ECC value is near zero, the Negative value of TARC, the CCL is less than 0.08, the DG is near 10 dB and the MEG value is zero. The response of all diversity parameters is within the allowable range. The presented design opens a new way to target 5G and WLAN-related applications.

The miniJPAS survey

Context. Galaxy clusters are an essential tool to understand and constrain the cosmological parameters of our universe. Thanks to its multi-band design, J-PAS offers a unique group and cluster detection window using precise photometric redshifts and sufficient depths. Aims. We produced galaxy cluster catalogues from miniJPAS, which is a pathfinder survey for the wider J-PAS survey, using the PZWav algorithm. Methods. Relying only on photometric information, we provide optical mass tracers for the identified clusters, including richness, optical luminosity, and stellar mass. By reanalysing the Chandra mosaic of the AEGIS field, alongside the overlapping XMM-Newton observations, we produced an X-ray catalogue. Results. The analysis revealed the possible presence of structures with masses of 4 × 1013 M⊙ at redshift 0.75, highlighting the depth of the survey. Comparing results with those from two other cluster catalogues provided by AMICO and VT, we found 43 common clusters with cluster centre offsets of 100 ± 60 kpc and redshift differences below 0.001. We provide a comparison of the cluster catalogues with a catalogue of massive galaxies and report on the significance of cluster selection. In general, we were able to recover approximately 75% of the galaxies with M⋆ > 2 × 1011 M⊙. Conclusions. This study emphasises the potential of the J-PAS survey and the employed techniques, including down to group scales.

In-flight performance of the Multi-band Uncooled Radiometer Instrument (MURI) thermal sensor

NASA's Earth Science and Technology Office (ESTO) encourages and promotes new and innovative science technologies to improve how the Earth is observed from space. Through their Instrument Incubator Program (IIP), an uncooled multispectral thermal instrument was fabricated and flight-tested to demonstrate its potential utility to support future spaceborne missions. While uncooled systems offer the attractive advantage of eliminating the need for large and expensive cryocoolers, they naturally introduce challenges that must be overcome to achieve the fidelity observed in image data acquired by existing cooled spaceborne instruments.In this work, the Multi-band Uncooled Radiometer Instrument (MURI) system, designed and built by Leonardo DRS, is fabricated using custom microbolometer detector arrays also developed by Leonardo DRS. Potential issues associated with thermal imaging using microbolometers from a spaceborne platform are discussed and innovative engineering solutions to overcome these issues are highlighted. Details of three airborne campaigns designed to assess the fidelity of MURI image data, using Landsat 8's Thermal Infrared Sensor's (TIRS) radiometric & geometric requirements as a baseline, are presented. Results of these campaigns show that the as-built MURI system significantly outperforms these requirements, as compared to ground-based reference measurements. Sustainable Land Imaging (SLI) requirements indicate that a five-band instrument is desirable to improve future Landsat science while maintaining continuity with previous thermal instruments. Considering its multiband design, temperature/emissivity separation (TES) is applied to MURI flight data and compared to ground-based spectrometer measurements for several materials. Results of this study indicate that MURI's TES performance is in-line with existing spaceborne systems. When considered in conjunction with its radiometric fidelity, the MURI uncooled system represents an intriguing option for future space-based missions.

Neural network inverse model for multi-band unequal Wilkinson power divider

PurposeThe purpose of this paper is to build a neural network (NN) inverse model for the multi-band unequal-power Wilkinson power divider (WPD). Because closed-form expressions of the inverse input–output relationship do not exist, the NN becomes an appropriate choice, because it can be trained to learn from the data in inverse modeling. The design parameters of WPD are the characteristic impedances, lengths of the transmission line sections and the isolation resistors. The design equations used to train the NN inverse model are based on the even–odd mode analysis.Design/methodology/approachAn inverse model of a multi-band unequal WPD using NNs is presented. In inverse modeling of a microwave component, the inputs to the model are the required electrical parameters such as reflection coefficients, and the outputs of the model are the geometrical or the physical parameters.FindingsFor verification purposes, a quad-band WPD and a penta-band WPD are designed. The results of the full-wave simulations verify the validity of the design procedure. The resulting NN model outperforms traditional time-consuming optimization procedures in terms of computation time with acceptable accuracy. The designed WPDs using NN are implemented by microstrip lines and verified by using full-wave analysis based on high-frequency structure simulator (HFSS). The results of the microstrip WPDs have good agreements with the corresponding results obtained by using ideal transmission line sections.Originality/valueThe associated time-consuming procedure and computational burden in realizing WPD through optimization are major disadvantages; needless to mention the substantial increase in optimization time because of the multi-band design. NNs are one of the best candidates in addressing the abovementioned challenges, owing to their ability to process the interrelation between electrical and geometrical/physical characteristics of the WPD in a superfast manner.

Novel operating band design schemes for high-contrast passive terahertz security screening systems

A passive terahertz security screening system utilizes the contrast of imaged targets in the terahertz band to identify concealed contraband. The variety of covered clothing textures presents a wide distribution of transmission characteristics, resulting in the diversity of high-contrast detection frequencies within the terahertz band. Thus the commonly used single operating band system modelled under one clothing texture is inadequate in multi-type clothing scenarios in practical applications. In this study, the concept of relative contrast is proposed for the detection of concealed metal contraband, and the relationship between the operating band and relative contrast is revealed. Two novel operating band design schemes, a reconfigurable multi-band single-system design and a fixed multi-band dual-system design, are presented. Computer simulation results show that these two design schemes can effectively improve the imaging contrast and enhance the detection effect of passive terahertz security screening systems.

Design and Analysis of Multi Band Notched MIMO Antenna for Portable UWB Applications

A MIMO antenna having circular patch with CPW feeding is proposed in this paper. Design, Simulation, Fabrication and testing of MIMO antenna with different band notching characteristics are proposed in this paper. The designed antennas are suitable for portable UWB applications. UWB is the most promising technology which provides high data rate with in short range. In 2002 Federal Communication Commission (FCC) has approved a frequency band of 3.1–10.6 GHz for unlicensed applications. Within the band of UWB some of the wireless Communication bands with different frequencies are also operating. So to avoid interference, band dispensation characteristics are proposed. In this paper single dual, triple and quad band notch MIMO antennas are designed, simulated and tested and their results are reported. Elimination of interference with existing wireless bands like WiMAX, WLAN, X—Band Satellite Communication System and ITU is the prime focus of the paper. Concentric rings with rectangular split bricks are placed on the patch to eliminate the interference with the existing bands. Different antennas are designed and simulated using CST microwave studio software and the antenna parameters like Return losses (S11), Gain, VSWR, Radiation patterns and Correlation Coefficient are measured. Quad band notch antenna is fabricated using RT/Duroid 5880 substrate material with height 1.57 mm. To get better Isolation the antennas are placed vertically and a stub is placed in between the antennas. The quad band antenna able to notch WiMAX, WLAN, X—band and ITU band and port Isolation (S12) is very good and envelope correlation is below 0.001 in UWB frequency spectrum.

A DESIGN OF MULTIBAND NESTED SQUARE SHAPED RING FRACTAL ANTENNA WITH CIRCULAR RING ELEMENTS FOR WIRELESS APPLICATIONS

A DESIGN OF MULTIBAND NESTED SQUARE SHAPED RING FRACTAL ANTENNA WITH CIRCULAR RING ELEMENTS FOR WIRELESS APPLICATIONS

Design of a compact multiband circularly polarized antenna for global navigation satellite systems and 5G/B5G applications

Over 3m from publication. May be compliant through Glasgow repository https://eprints.gla.ac.uk/210681/

Design of Multiband Switching Illumination With Low-Concentration Lugol Stain for Esophageal Cancer Detection

Narrowband imaging (NBI), flexible spectral imaging color enhancement (FICE), and Lugol chromoendoscopy (LCE) are used in endoscopy of head and neck cancers and esophageal cancers. The NBI and FICE techniques enhance the capillary pattern in cancerous areas, whereas in LCE, normal and cancerous areas are differentiated using Lugol solution. Although invasive, LCE is more sensitive than NBI and FICE for this purpose. In this study, we propose a relatively less invasive and highly sensitive technique for detecting cancerous areas that combines low-concentration Lugol stain and narrowband illumination. This combined technique requires the use of an endoscopic system that can acquire RGB images synchronized with narrowband illumination switching. This technique produces a large number of images that can potentially discriminate smaller differences in color than is possible with conventional RGB imaging. Experiments to predict the performance of the proposed method were performed using four resected specimens, including esophageal cancer, and promising results were obtained.

The Design and Fundamentals of Printed Antennas [Book/Software Reviews

This book focuses more on practical antenna design than theoretical analysis and presents a good balance between fundamentals and the printed antenna design. This text concentrates on real-world antenna design and avoids too many formulations and theories. Includes topics that cover fundamentals of printed and microstrip antennas. These principles are presented in a logical way, beginning with an examination of single-element printed antennas and moving on to a system- level review of printed antenna fundamentals, antenna design techniques, and real-world, application-based antenna designs. The book also features information on an overview of antenna design used in smartphones; various compliance requirements of mobile phone antenna designs; frequency and polarization reconfiguration; printed ray antennas, microwave remote sensing; phased array antennas; automobile antenna design, and recent research and development trends in the design, analysis, and synthesis of broadband, multiband, and reconfigurable antenna for modern wireless systems. Taken together, the chapters provide several antenna design projects to demonstrate antenna design steps, antenna physical dimensions, and simulation results. This book begins with a very basic introduction of ultrawideband (UWB) antenna theory and a simple explanation of each type of UWB antenna. This is a perfect starting point for entry-level UWB antenna designers, equipment designers, and operators.

A novel dual band patch design for electrical steerable reflectarray antennas

ABSTRACTReflectarray antennas do not necessarily exhibit a better antenna efficiency compared to ordinary reflector antennas. However, flat structure, multiband design capability, and specially, possibility of electrical beam scanning of this type of antenna are attractive to the antenna designers and researchers. By using elements with electrically tunable reflection phases, it is possible to design an electrically steerable beam reflectarray. In this paper, a novel dual band element is presented for which the reflection phase within each band can be controlled independently. Therefore, the reflectarray arranged by this element can perform the functions of two electrically steerable antennas simultaneously. An aperture coupled element and a miniaturized diplexer are used in the proposed structure. The reflection phase of the designed element can be controlled by changing the lengths of the output lines of the diplexer. It is possible to electrically change this line length using MEM switches. As a result, a dual band reflectarray with independent electrical beam scanning capabilities in each of its frequency bands is obtained.

Low-Cost Multi-Objective Optimization of Multiparameter Antenna Structures Based on the l1 Optimization BPNN Surrogate Model

The development of modern wireless communication systems not only requires the antenna to be lightweight, low cost, easy to manufacture and easy to integrate but also imposes requirements on the miniaturization, wideband, and multiband design of the antenna. Therefore, designing an antenna that quickly and effectively meets multiple performance requirements is of great significance. To solve the problem of the large computational cost of traditional multi-objective antenna design methods, this paper proposes a backpropagation neural network surrogate model based on l1 optimization (l1-BPNN). The l1 optimization method tends to punish larger weight values and select smaller weight values so as to preserve a small amount of important weights and reset relatively unimportant weights to zero. By using l1 optimization method, the network mapping structure can be automatically adjusted to achieve the most suitable and compact structure of the surrogate model. Furthermore, for multi-parameter antenna design problems, a fast multi-objective optimization framework is constructed using the proposed l1-BPNN as a surrogate model. The framework is illustrated using a miniaturized multiband antenna design case, and a comparison with previously published methods, as well as numerical validation, is also provided.

Advanced technologies for next‐generation RF front‐end modules

The complexity of RF front-end (RFFE) modules of wireless devices has increased dramatically over the past decade. In order to meet the demands for future mobile communications, RFFEs will need to enable multiband for global roaming, and multi-mode to support multiple cellular modes, incorporate beamforming antennas, and operate at mmwave frequencies. To this end, this paper presents a summary of the recent progress in RF substrate technologies, waveguide architectures and multi-band design techniques for 5G RFFE modules, and summarizes the present and future challenges in RFFE module design.

Multiband and Wideband 90° Polarization Rotators

Inspired by techniques utilized in the design of frequency-selective surfaces, multiband and wideband 90° polarization rotators are proposed in this letter. The basic structure is constructed from three layers. The front and back layers contain metal wire grids orthogonal to each other, whereas the middle layer consists of resonant elements with 45°-twisted angle, which plays the main role in determining the overall response of the structure. Employing single and multiple resonators in the middle layer, first-order single- and multiband are achieved. By cascading two first-order middle layers, a second-order response is accomplished. A very wideband response is achieved by utilizing a wideband resonant element in the middle layer. Several design examples are presented and simulated, two of them are fabricated and tested to validate the simulated results.

Resolving Braess-Like Paradoxes in General Wireless Ad Hoc Networks

Coordinating medium access for a massive number of devices is challenging in general wireless ad hoc networks, such as cognitive radio networks and device-to-device (D2D) communication networks. To facilitate medium access, it is often desirable to gather some channel side information (CSI) at the transmitter side such as the channel availability in cognitive radio networks and the channel state information in D2D communication networks. In addition, since it is usually costly to gather the CSI for a large number of devices in a centralized way, distributed medium access control becomes attractive, where each user collects its own CSI to support autonomous and scalable data transmission. However, in the literature, there lacks a systematic way to understand the value of such CSI in the overall network performance. Game theory is often a natural choice for modeling the autonomous and strategic behavior of users. In this paper, we first formulate the multi-band random access game and design a polynomial time algorithm to identify the mixed strategy Nash equilibrium. Then, we propose a systematic framework to incorporate the CSI into the decision making based on the Bayesian game approach. We analyze how the knowledge of the CSI affects the equilibrium strategy and measure the value of this CSI knowledge by the utility difference. We resolve Braess-like paradoxes in general wireless ad hoc networks.

Miniaturized Multiband HTS Bandpass Filter Design Using a Single-Perturbed Multimode Resonator With Multitransmission Zeros

This paper presents a miniaturized quint-band high-temperature superconducting (HTS) bandpass filter (BPF) based on a single-perturbed multimode resonator (PMMR). By properly adjusting the lengths and the position of the perturbation line in a PMMR, the intrinsic resonance modes can be controlled, which is advantageous for multiband design. The source-load coupling, spurlines, and matching stubs on feedlines are introduced to improve impedance matching and to generate multi transmission zeros, so that enhanced isolation and harmonics suppression can be realized. A low insertion loss (IL) within each band is obtained by using an HTS technology. The filter is fabricated on an MgO substrate with the YBCO thin films, and measured at the temperature of 77 K. The passband measurement is consistent with the simulation, which verifies five passbands located at 0.56, 1.52, 3.8, 4.7, and 5.3 GHz, respectively. A low-measured IL with less than 0.2 dB level is obtained due to the application of a superconducting technology. The proposed HTS BPF owns the great merits of a simple structure, a miniature size (0.008λ g 2 ), an enhanced upper stopband, and a low IL.

Design of Multi band Notched U-Shaped Microstrip Antenna

Design of Multi band Notched U-Shaped Microstrip Antenna

航天光学遥感相机多谱带滤光片设计与考核方法

航天光学遥感相机多谱带滤光片设计与考核方法

Bio-Inspired Algorithms Applied on Microstrip Patch Antennas: a Review

Design of small broadband, multiband and high-directivity microstrip patch antennas (MPAs) is a challenging task for the antenna research community since the classical MPAs do not perform well enough to be used in the real world applications. In this sense, various performance improvement techniques such as stacked patches, air gaps, compact meandering geometries, fractal-shapes and shorting pins are applied to design improved MPAs. Use of bio-inspired algorithms along with these techniques is trending due to their capability of manipulating antenna parameters to achieve optimized performance. Literature presents use of bio-inspired algorithms such as Genetic algorithms (GA), Particle swarm optimization (PSO), Differential evolution (DE), Invasive weed optimization (IWO), Wind driven optimization (WDO) and Ant colony optimization (ACO) on MPAs for performance enhancement. This paper begins with an introduction to MPAs followed by an analysis of the performance improvement techniques. Evolution of bio-inspired algorithms and their applications in the field of MPAs are also presented. Based on the compilation of studies, importance of applying multi-objective bio-inspired algorithms for simultaneous optimization of multiple antenna parameters is emphasized. Further, research voids in the field are revealed and direction is shown to design compact multifunctional MPAs.

Performance enhancement of multiband antennas through a two-stage optimization technique

This paper presents an optimization technique that aims at multiband antenna design. The proposed method is based on the framework of multi-objective evolutionary algorithms, and a two-stage mechanism that balances the degree of optimizing impedance matching and the degree of providing a wide impedance bandwidth is incorporated. Conventionally, the design optimization of multiband antennas relies on minimizing the maximum reflection coefficient or maximizing the area under the return-loss curve over targeted frequency bands. However, these widely used methods direct an optimization algorithm to improper solution sub-domains in the multiband design problem. To overcome the limitation of these conventional methods, the general rule of objective functions is thoroughly investigated in this paper. Furthermore, a two-stage optimizer is designed based on what the multiband optimization problem needs. With the use of the proposed method, two multiband antennas for mobile communication systems covering 824–960 MHz and 1710–2170 MHz are successfully developed. Simulated and measured results show that the proposed technique outperforms conventional optimization approaches significantly.