Profile Configuration Research Articles

A Wide-Angle and High-Efficiency Reconfigurable Reflectarray Antenna Based on a Miniaturized Radiating Element

A wide-angle reconfigurable reflectarray antenna (RRA) was designed and experimentally verified utilizing a miniaturized ring patch efficiently controllable with a single bit. Based on the merits of the miniaturization of the radiating element and an elaborate study of the quantization efficiencies of the asymmetric phase differences between the on/off states of the unit cell by optimizing a reference phase on the metasurface, highly directive beam scanning is achieved in a wide ±60° range in both the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H</i> - and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</i> -planes. Furthermore, the illumination and spillover efficiencies and focal diameter ratio (F/D) are carefully optimized, resulting in a low profile configuration with F/D=0.36. The fabricated RRA prototype was measured at 9.85 GHz (X-band) with the highest aperture efficiency of 28% and a 1 dB gain bandwidth of 530 MHz, respectively.

Discrete curvature-based shape configuration of composite pipes for local buckling detection based on fiber Bragg grating sensors

For the high strength, good corrosion resistance and stability, carbon fiber reinforced polymer (CFRP) composites can be made into pipes to transfer gasses and oils in submarine environment. Structural performance and shape of CFRP composite pipes are particularly important to sustain the regular operation of the delivery system. To obtain the in-field shape and identify the local buckling of CFRP composite pipes, quasi-distributed optical fiber sensing techniques have been developed based on the multiplex of fiber Bragg grating (FBG) sensors. Theoretical investigation on shape profile configuration of the pipes based on the measured strains has been performed. Relationship between the accuracy of configuration algorithm and the sensor layout has also been explored. Experiments have been conducted to check the effectiveness and accuracy of the proposed sensing technique and curve configuration algorithm. Results validate good measurement performance of the proposed sensors and high accuracy of the shape-configuration algorithm. Suggestions on the sensor layout of long-distance pipe structures are provided with the comprehensive consideration of overall structural shape control and economical factor. The study can be adopted to instruct the establishment of the structural health monitoring system, identify the buckling and assess the safety operation of pipe structures.

Response analysis of a multi-story building structure with a variety of horizontal irregularities and shear wall geometries

The growing growth of human activities has led to changes in housing patterns in urban areas. The land crisis in urban areas has made land prices uneconomical, so buildings are designed vertically. One solution to resist earthquakes in multi-story buildings is to add a shear wall structure with the proper profile and layout. Shear wall designs with variations influence the base shear, drift ratio, lateral deflection, and story drift patterns. This study presents the structural response comparison of buildings against variations in the profile and layout of shear walls subjected to earthquake loads. Force Based Design method utilizing the response spectrum approach was adopted in the analysis and carried out using SAP200. Six structural models comprise a frame without shear walls, three L-profile shear walls, two I-profile (straight) shear walls. The simulation results of the overall structural models show that the profile and layout configuration of shear walls in the frame structure of a multi-story building correlates directly to the performance of base shear, drift ratio, and story drift with relatively comparative conditions.

Neutronics and shielding design of CFETR HCCB blanket

Tritium breeding blanket (TBB) is one of the most important components of China Fusion Engineering Test Reactor (CFETR) with functions of tritium breeding, heat generating and nuclear shielding. This paper presents the progress on the neutronics and shielding design of the helium cooled ceramic breeder tritium breeding blanket (HCCB TBB) developed by the Southwestern Institute of Physics (SWIP). Based on the latest profile and layout configuration of CFETR TBB, the preliminary neutronics design, optimization and analysis of HCCB TBB have been completed. After several rounds of neutronics design and optimization, the TBR of HCCB TBB is 1.177, and the value drops to 1.101 considering the influence of auxiliary systems, which can meet the design objectives of CFETR. The total nuclear heating of HCCB TBB is 1402 MW with 1500 MW fusion power. Among all the blanket modules, blanket module #3 is subjected to the strongest neutron irradiation. Meanwhile, the overall shielding analysis for TF coils of CFETR has been performed based on the current design of HCCB TBB, and the preliminary shielding design and optimization for the weak shielding areas such as HCCB TBB, divertor and neutral beam injector (NBI) port have been carried out. After shielding optimization, the fast neutron fluence and nuclear heating of all TF coils are below the design limit. By increasing the number of source neutron histories and using some variance reduction techniques in the MCNP calculation, the relative errors of neutronics and shielding analysis results for HCCB TBB are all less than 5%.

Experimental Investigation of Drawbead Effect on Springback in Profile of Double Circular, Rectangular and Triangular Bending Sheet Metal Forming Processes

Springback is considered as one of the most common problems in metal forming processes, which poses an inaccuracy of product angle during assembling of parts. The estimation of the springback is difficult to predict for formed parts since it depends on many factors such as the mechanical properties, the sheet thickness, and the die angle. In this work, an experimental investigation of drawbead for different material thicknesses and the use of different lubricants such as grease, oil and wax have been studied and analyzed. Samples of aluminum specimens with 120 mm length, 30 mm width and thickness of 0.5, 0.7 and 0.8 mm were selected in this study. Design and manufacturing of double bending die with profile of Circular, Rectangular, and Triangular have been applied firstly without drawbead and then with drawbead. The results showed that in a given profile configuration, the springback reduced with existing the drawbead

Skeletal and dentoalveolar contributions during ClassII correction with Forsus™ FRD appliances : Quantitative evaluation.

Primary objective of the study is to quantify and evaluate the skeletal and dental contributions during sagittal ClassII correction with the Forsus™ fatigue resistant device (FRD; 3M Unitek Corp., Monrovia, CA, USA). Secondary objective is to evaluate the overall vertical, soft tissue and chin-throat relation changes with the Forsus™ appliance. Aretrospective sample of 27ClassII patients treated with the Forsus™ FRD appliance was compared to 20untreated control subjects who were matched according to age and craniofacial morphology. Pre-Forsus™ (T0) and Post-Forsus™ (T1) cephalograms were subjected to composite cephalometric analysis. Growth changes were subtracted from the treatment changes to obtain the treatment effects of the appliance. The data were analyzed using Student's t‑test and independent ttest. Significant differences were found between the treated and the control group in 16of 29measured variables. The overjet and molar relation improved by 4.23 mm and 4.49 mm, respectively. This was mainly achieved by backward movement of maxillary incisors (1.4 mm) and molars (1.22 mm) and forward movement of mandibular incisors (2.26 mm) and molars (2.70 mm). Overbite decreased by 2.24 mm with no changes in mandibular and nasal plane angles. The Forsus™ FRD was effective in correcting ClassII malocclusion mainly at the dentoalveolar level. The net skeletal and dentoalveolar contributions towards both overjet and molar correction was 13% and 87%, respectively. The improvement in soft tissue profile and chin-throat configuration was statistically insignificant.

Low-Profile Metasurface-Based Antenna With Tripolarization for 5G Applications

This article develops a novel low-profile meta-surface-based tripolarized antenna with complementary patterns for fifth-generation (5G) application. A shared aperture metasurface-based structure is first proposed, which is carefully studied by equivalent circuit models and field distribution. Then, to realize multiple polarization operation, the TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> , antiphase TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">20</sub> , and TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">00</sub> modes are used and excited by suitable feeding networks. For horizontal polarization, wideband response is realized by coupling and combining the TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> /TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">20</sub> dual modes. An inductance-loaded TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">00</sub> mode is displayed by loading the shorting vias on the metasurface, which is used to implement vertical polarization. Finally, a metasurface-based tripolarized antenna with a low profile of 0.04λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ( λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> is the free space wavelength at 3.30 GHz) is fabricated. The overlapped 10-dB bandwidths for all excitations are from 3.26 to 3.84 GHz (16.3%) with isolation greater than 22 dB, which well covers the 5G-N78 band. The measured peak gain and radiation efficiency are larger than 10.3 dBi and -0.42 dB (90.8%), respectively. The results indicate that the proposed antenna with a low profile, a simple and low-cost configuration, multipolarization, good bandwidth, high radiation efficiency, and gain performance could be widely used in sub-6 GHz 5G communication systems.

Multi‐beam SIW leaky‐wave antenna with 2‐D beam scanning capability for millimeter‐wave radar applications

In this article, a multi-beam substrate integrated waveguide (SIW) leaky-wave antenna (LWA) is proposed for millimeter-wave radar applications, which owns the advantages of 2-D scanning capability, high gain, low profile, and single layer configuration. The proposed antenna consists of a beam-forming network (BFN) based on a 2-D SIW parabolic reflector with eight waveguide feedings, and a 16-element LWA array. The open-stopband of the LWA is suppressed by employing a longitudinal slot into a conventional transverse slot LWA unit. In the E-plane, the BFN can generate eight desired distributions of the amplitude and the phase gradients which steers beam from −17.3° to 30.8° with the crossover level higher than −5.22 dB. In the H-plane, the frequency scanning LWA array can offer a continuous beam scanning range from −23° to 19° with operating frequency from 21 to 29 GHz. Finally, the antenna is prototyped and experimentally verified. The measured results are in accord with the simulated ones. The characteristics of the proposed antenna make it a very promising solution for applications in low-cost millimeter-wave radar systems.

ПОВЫШЕНИЕ ЖЕСТКОСТИ КОНСТРУКЦИИ АЛЮМИНИЕВОЙ ГОФРИРОВАННОЙ ВИТОЙ ШПУЛИ

The paper presents the results of a computational and experimental study of aluminumspools with different profile configurations. Mathematical modeling of the product was made using ANSYS 18.2 software package. Models were verified based on actual test results on FP-100/1-10tn testing machine in JSC “Arconic SMZ” Central Factory Lab as per valid normative documents. The study was made on a trial lot of spools with a specially developed type of profile. Comparative analysis was carried out against purchased spools with a profile previously developed by the spool supplier.The spools under study were made of alloy 3104 H19, 0.26 mm strip thickness. The study resulted in work out of empirical formulas helping to determinecollapse loadand calculate the amount of metal forevaluationof stiffness-to-weight ratio. The proposed formulas were added with dimensionlesscoefficients to account for the profile configuration (shape factor) and the relative height of the profile wall.The coefficients were presented in the form of nomograms for easygraphical assessment of the profile performance.The critical height of the profile was determined, at which specific stiffness of the structure is the highest.It was demonstrated that a profile with an inclined vertical wall and a profile with an omega-shaped inner generatrix have lower stiffness than a profile with vertical U-shaped corrugations.The optimal range of the corrugation wall tilt angle was determined to ensure the required level of the structure stiffness, on the one hand, and minimize metal consumption, on the other hand. Comparison of the results of model calculations, the results of computation by the proposed empirical dependencies and actual experimental data showed their high repeatability, whichleads to the conclusion that the proposed formulas are applicable for engineering calculations.The developed profile of a special type makes it possible to reduce the spool metal consumption by 13% while maintaining the required strength performance and the level of stiffness.

Rebuilding the wheelset flanges of locomotives by surfacing without wheeling out

The most effective method to increase the surface life of wheel tires, the flange wear of which outpaces the growth of tire wear significantly, is surfacing of worn flanges of electric locomotive wheel sets. This method, in comparison with the restoration by turning and forming a profile configuration by reducing the thickness of the tire has undeniable advantages: flange surfacing combined with the shape of female profile minimizes the technological wear of the tire before its retirement; idle time of locomotives caused by the need of intermediate turning is eliminated; the costs of maintaining the machines for turning without removing the wheels and purchasing hard-alloyed cutting tools are decreased; wage savings are achieved. The work presents basic information on wheel sets, theoretical data on surfacing, analyzes previously used surfacing materials and provides metallographic studies of the surfaced material. The technology of flange surfacing without removing the wheels from under the electric locomotive was developed and described, that allows reducing the time spent on repair significantly. The use of alloyed surfacing materials instead of low-carbon ones allows reducing the time of surfacing and increasing the resistance to wear of wheel set flanges of traction vehicles. Efficiency of NP-18H1G1M.01 surfacing wire application for wear-resistant surfacing of tire flanges and increase of the overhaul cycle is shown. Increased wear resistance of electric locomotive wheel flanges surfaced with alloyed wire is confirmed by the production test data.

Parameterization analysis and field validation of VTI-elastic full-waveform inversion in a walk-away vertical seismic profile configuration

Elastic full-waveform inversion (FWI) in transversely isotropic media with a vertical symmetry axis (VTI) is applied to field walk-away vertical seismic profile (W-VSP) data acquired in Western Canada. The performance of VTI-elastic FWI is significantly influenced by the model parameterization choice. Synthetic analysis based on specific field survey configuration is carried out to evaluate three different VTI-elastic model parameterizations. Interparameter trade-offs are quantified using the recently introduced interparameter contamination sensitivity kernel approach. Synthetic results suggest that neglecting anisotropy leads to inaccurate velocity estimations. For the conventional vertical velocity-Thomsen’s parameter parameterization (i.e., vertical P-wave velocity, vertical S-wave velocity, Thomsen’s parameters [Formula: see text] and [Formula: see text]), a sequential inversion strategy is designed to reduce strong natural interparameter trade-offs. The model parameterizations of elastic-constant ([Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text]) and velocity-based (vertical, horizontal, and normal move-out P-wave velocities and vertical S-wave velocity) models appear to suffer from fewer interparameter trade-offs, providing more reliable velocity and anisotropy models. Results derived from application of VTI-elastic FWI to the field W-VSP data set tend to support the synthetic conclusions. Multiparameter point spread functions are calculated to quantify the local interparameter trade-offs of the inverted models. The output inversion results are interpreted to provide valuable references regarding the target hydrocarbon reservoir.

Using DEM to investigate how shell liner can induce ball segregation in a ball mill

Sometimes it is desirable to segregate the ball load in a mill so as to allow for the possibility of larger balls dealing with coarser particles at the feed end and finer product being ground more efficiently at the discharge end. The Hardinge mill with cylindrical and conical sections has been used to achieve segregation quite effectively. The cylindrical section tends to retain the biggest balls while the smaller balls drift to the conical section. However, this is a complex design and we use the discrete element method (DEM) model to investigate if simply altering liner configuration on an ordinary cylindrical mill can lead to similar success. The study involves simulating a mill with 4 sections. Each section can be configured with distinct liner profiles. Three ball size classes are tracked for evidence of segregation at 75% and 60% of critical mill rotation speed. The ball distributions in the various segments at the end of 80 mill revolutions suggest that varying axial liner profile configuration can affect ball segregation, particularly for the mill running at 75% of critical speed. The convenience of using computer simulations to avoid costly plant trials is highlighted.

Soft tissues cephalometric norms for a sample of Sudanese adults. Part I: Legan and Burstone analysis

ABSTRACT Purpose: To establish soft tissues cephalometric norms for orthognathic surgery in a sample of Sudanese adults. Materials and Methods: A total of 106 lateral cephalograms of Sudanese adults (55 females and 51 males) aged between 18 and 25 years (mean 22.8 years) were manually traced and analysed using Legan and Burstone Cephalometric analysis for orthognathic Surgery (COGS). Results: Sudanese sample, in comparison to Caucasian, had a more convex profile with larger angle of convexity and more prognathic maxillae, obtuse lower face-throat angle, more acute nasolabial angle, protrusive upper and lower lips with deeper labiomental sulci and greater maxillary incisors exposure with larger interlabial gap. Males had greater maxillary and mandibular prognathism, more obtuse lower face-throat angle and vertical height depth ratio than females. Females had larger vertical lip chin ratio, maxillary incisor exposure and interlabial gap. Conclusion: Considerable differences between the soft tissue profile configuration of Sudanese and Caucasian adults exist and also between Sudanese and other populations. These variations should be taken into account during diagnosis and treatment planning of orthognathic surgery.

Development of a Shock and Detonation Velocity Measurement System Using Chirped Fiber Bragg Gratings.

Dynamic measurements of shock and detonation velocities are performed using long chirped fiber Bragg gratings (CFBGs). Such thin probes, with a diameter of typically 125 µm or even 80 µm can be directly inserted into high-explosive (HE) samples or simply glued laterally. During the detonation, the width of the optical spectrum is continuously reduced by the propagation of the wave-front, which physically shortens the CFBG. The light power reflected back shows a ramp-down type signal, from which the wave-front position is obtained as a function of time, thus yielding a detonation velocity profile. A calibration procedure was developed, with the support of optical simulations, to cancel out the optical spectrum distortions from the different optical components and to determine the wavelength-position transfer function of the CFBG. The fitted slopes of the X–T diagram give steady detonation velocity values which are in very good agreement with the classical measurements obtained from discrete electrical shorting pins (ESP). The main parameters influencing the uncertainties on the steady detonation velocity value measured by CFBG are discussed. To conclude, different HE experimental configurations tested at CEA (Commissariat à l’Energie Atomique et aux Energies Alternatives) are presented: bare cylindrical sticks, wedges for shock-to-detonation transitions (SDT), spheres, a cast-cured stick around a CFBG, and a detonation wave-front profile configuration.

Homogeneous or Heterogeneous I.Q Profile: Some Clinical Characteristics to Differentiate High Intellectual Potential and Aspergers Syndrome in Children

Background: Some recent studies suggested that the homogeneous versus heterogeneous psycho-cognitive profiles established by the Wechsler scales are relatively good predictors of the behavioral characteristics and general adaptive abilities of children with high intellectual potential (HIP). First, the present study aimed to test the hypothesis that the heterogeneous IQ profile can be linked to social, behavioral and emotional difficulties in children with HIP. Secondly, by comparing HIP children and children with Asperger’s syndrome combined with HIP, our purpose was to identify possible clinical characteristics to differentiate these profiles. Materials and Methods: We carried out a comparative study between HIP children with a homogeneous IQ profile, HIP children with a heterogeneous IQ profile, children with an Asperger’s syndrome combined with HIP and children with typical development. A total of 62 children, aged between 7 years and 7 months and 15 years and 11 months, were recruited for this research. The WISC-IV was used to identify children with HIP. Appropriated tests were used to assess respectively, social cognition and emotional adaptation, the visuoperceptual and visuomotor functions and the prevalence of anxiety and depressive disorders. Results: The existence of links were confirmed between profile configuration and the interactional abilities of HIP children. Certain registers of social cognition and affectivity could represent possible indicators for distinguishing very high-functioning Asperger’s syndrome and HIP without Autism Spectrum Disorders. Conclusion: HIP children with a very heterogeneous IQ profile and considerable social and emotional difficulties are at high risk of being children with Asperger's syndrome.

Evaluation of Wind Resources Potential and Economic Analysis of Wind Power Generation in South Africa

The presence of adequate renewable energy resources and the rapid development of wind projects in South Africa have led to mapping out of the country’s wind capability. In view of this, the economic prospects of utilizing wind energy as a potential energy alternative in South Africa are examined and discussed from the perspectives of green energy strategies for sustainable energy development. This research work is designed to investigate the economic effects of using the wind turbine (WT) in ten locations in South Africa based on the grid planning and power sector reform. The HOMER application software is utilized in this study to assess the wind resources on provincial and national scales, along with estimating the annual energy generation of the selected locations. The wind energy potential of South Africa is analysed by utilizing the capacity factor (CF), wind penetration and mean output of the WT for various locations in South Africa. The results obtained from the study indicate that the selected sites fall within the range of Class 1V of IEC wind classifications with the annual average wind speed of 4.04 m/s for Pretoria and 6.39 m/s for Cape Town at 50m hub heights. The economic assessment of the WT for electric power generation is carried out by using some key performance indicators (KPIs) such as net energy purchased, energy sold, revenue, grid energy purchased, annual utility bill savings, net present cost (NPC) and cost of energy (COE). It is established from the study that Cape Town is the most suitable location for installation of the WT by utilizing the same load profile and system configuration. The output of this research work can be used by the renewable energy development agencies as inputs to harness the potential of wind resources for strategic planning of the power sector reform and industrial development.

Numerical Study of Variable Camber Continuous Trailing Edge Flap at Off-Design Conditions

Numerical simulations are performed to study the outboard airfoil of advanced technology regional aircraft (ATRA) wings with five different variable camber continuous trailing edge flap (VCCTEF) configurations. The computational study aims to improve the aerodynamic efficiency of the airfoil under cruise conditions. The design of outboard airfoil complies with the hybrid laminar flow control design criteria. This work is unique in terms of analysis of the effects of VCCTEF on the ATRA wing’s outboard airfoil during the off-design condition. The Reynolds–Averaged Navier–Stokes equations coupled with the Spalart-Allmaras turbulence model are employed to perform the simulations for the baseline case and VCCTEF configurations. The current computational study is performed at an altitude of 10 km with a cruise Mach number of 0.77 and a Reynolds number of 2.16 × 107. Amongst all five configurations of VCCTEF airfoils studied, a flap having a parabolic profile (VCCTEF 123) configuration shows the maximum airfoil efficiency and resulted in an increase of 6.3% as compared to the baseline airfoil.

Morphodynamics of an Artificial Cobble Beach in Tianquan Bay, Xiamen, China

By tracking and monitoring the profile configuration, topography, and hydrodynamic factors of an artificial cobble beach in Tianquan Bay, Xiamen, China over three consecutive years after its completion, we analyzed the evolution of its profile configuration and plane morphology, and its storm response characteristics. The evolution of the profile configuration of the artificial cobble beach in Tianquan Bay can be divided into four stages. The beach was unstable during the initial stage after the beach nourishment the profile configuration changed obviously, and an upper concave composite cobble beach formed gradually, which was characterized by a steep upper part and a gentle lower part. In the second stage, the cobble beach approached dynamic equilibrium with minor changes in the profile configuration. At the third stage the beach was in a high-energy state under the influence of Typhoon Meranti, and the response of the artificial cobble beach differed significantly from that of the low-tide terrace sandy beach. Within a short time, there was net onshore transport of cobbles in the cross-shore direction. The beach face was eroded, the beach berm was accumulated, and the slope of the beach was steepened considerably. In the alongshore direction, there was notable transport of cobbles on the beach from east to west along the shore, and the total volume of the beach decreased by 4.5×103 m3, which accounted for 50% of the total amount of beach volume lost within three years. The fourth stage was the restoration stage after the typhoon, characterized by a little gentler profile slope and the increase in width and the decrease in height of beach berm. Because of the action of waves and the wave-driven longshore current caused by the specific terrain and landform conditions along the coast (e.g., coastal headlands, near-shore artificial structures, and reefs), the coastline of the artificial cobble beach gradually evolved from being essentially parallel to the artificial coast upon completion to a slightly curved parabolic shape, and three distinct erosion hotspots were formed on the west side of the cape and the artificial drainpipe, and the reefs. Generally, the adoption of cobbles for beach nourishment on this macro-tidal coast beach with severe erosion has yielded excellent stability and adaptability.

Performance analysis of a two-stage gravitational water vortex turbine

In the present study the performance of two-stage gravitational water vortex turbine (GWVT) assembled in a conical basin with Savonius blade profile configuration has been investigated at different flow rate and vortex elevation. Two-stage GWVT with conical basin, not only increases the performance parameters with increase in flow parameters, but the lower stages also feed additional impact to the stage located above it because of forced vortex generation in the vicinity of top stage. Moreover, maximum hydraulic head drop near the orifice is the main contributor in the power generation of the bottom stage, by giving rise to strong tangential velocity. A stage starts power production as soon as the parabolic surface of the vortex approaches the corners of the blades even in the absence of a significant water-blade interaction. The developed analytical model qualitatively predicts the performance of the turbine minutely leading the experimental results quantitatively.

RETRACTED: Development and design of antenna array for beam forming techniques

Antenna design has become as established field of research in recent years. The most important feature of microstrip patch antenna is low cost, low profile, and single-layer configuration. The freq...