Shape Of Antenna Research Articles

A comparative evaluation of microwave antenna designs performance on digital MR image in hyperthermia system

An efficient hyperthermia system is presented to evaluate and compare the performance of rectangular E-shape microwave antenna with two different circular shape antennas on digital magnetic resonance (MR) image of brain tumour that caters all the limitations. IE3D software is used to design microwave antennas for centre frequency of 2.45 GHz and a program is developed on MATLAB which shows how thermal imaging is done by applying the electromagnetic (EM) signal on the region of interest (ROI) in MR image of brain tumour. The system combines the data processing and analysis. It is simple and easy to use in order to obtain both quantitative values and images of temperature changes. Heating up to 45°C with minimal damage to surrounding healthy tissues is the prime focus of research. For real-time analysis, the antenna designs are fabricated and tested. The evaluated results illustrate the potential of designed antennas for hyperthermia treatment applicators.

Design and Simulation of E-Slot Patch Antenna with Coaxial Feed for Multi Band Applications

The main object of this paper is to design and to simulate micro strip slot patch antenna for multiband applications. It is omnidirectional and stable radiation pattern. Hence rectangular shape antenna can be simulated using ANSOFT HFSS software. Parameters such as return loss, VSWR and radiation pattern are taken. Micro strip slot patch antenna becomes very popular day to day because of easy analysis and fabrication, low cost, light weight, easy fabrication. This paper proposed some shapes using feeding techniques are which has effective transmission based on frequencies. Micro strip patch antennas offer an attractive solution compact, conformal and low cost design of many wireless application systems. By increasing the substrate thickness and decreasing the permittivity of substrate the percentage of band width is increased. HFSS software is used for simulation and design of micro strip patch antenna where its version is 11.0. HFSS means High Frequency Structure simulator this was launched by the ANSOFT, designs are four slot patch antennas and the antennas work in the frequency ranges as follows 4.15-4.39 GHz, 10-11.6 GHz, 13.2-14.3 GHz, 16-17.1 GHz, 19.1-20 GHz, 4.4-4.5 GHz, 8.7-9.1 GHz, 11.54-12.85 GHz, 1.65 GHz, 2.24 GHz, 4.4-4.6 GHz, 5.6- 5.8 GHz, 7.45-8.15 GHz It’s main objective is used for MIMO applications, WLAN, Wi-MAX and RADAR, UWB, mobile communications, satellite space communications and microwave frequencies.

A comparative evaluation of microwave antenna designs performance on digital MR image in hyperthermia system

An efficient hyperthermia system is presented to evaluate and compare the performance of rectangular E-shape microwave antenna with two different circular shape antennas on digital magnetic resonance (MR) image of brain tumour that caters all the limitations. IE3D software is used to design microwave antennas for centre frequency of 2.45 GHz and a program is developed on MATLAB which shows how thermal imaging is done by applying the electromagnetic (EM) signal on the region of interest (ROI) in MR image of brain tumour. The system combines the data processing and analysis. It is simple and easy to use in order to obtain both quantitative values and images of temperature changes. Heating up to 45°C with minimal damage to surrounding healthy tissues is the prime focus of research. For real-time analysis, the antenna designs are fabricated and tested. The evaluated results illustrate the potential of designed antennas for hyperthermia treatment applicators.

Organizing energy-and-information exchange between devices for controlling the shape of a transformable antenna, using fiber-optic technology

This paper analyzes the possibility of transporting energy and information to the actuators of a space-based transformable antenna along a fiber-optic channel. The main technical and functional requirements of such a system are considered, along with ways to put it into practice. A prototype of a fiber-optic system based on commercially available components for energy-and-information exchange between actuators has been assembled and tested.

Wide modulation bandwidth terahertz detection in 130 nm CMOS technology

Design, manufacturing and measurements results for silicon plasma wave transistors based wireless communication wideband receivers operating at 300 GHz carrier frequency are presented. We show the possibility of Si-CMOS based integrated circuits, in which by: (i) specific physics based plasma wave transistor design allowing impedance matching to the antenna and the amplifier, (ii) engineering the shape of the patch antenna through a stacked resonator approach and (iii) applying bandwidth enhancement strategies to the design of integrated broadband amplifier, we achieve an integrated circuit of the 300 GHz carrier frequency receiver for wireless wideband operation up to/over 10 GHz. This is, to the best of our knowledge, the first demonstration of low cost 130 nm Si-CMOS technology, plasma wave transistors based fast/wideband integrated receiver operating at 300 GHz atmospheric window. These results pave the way towards future large scale (cost effective) silicon technology based terahertz wireless communication receivers.

Creation of Graphene Plasmons Vortex via Cross Shape Nanoantennas Under Linearly Polarized Incidence

In this paper, we propose a method of creating plasmons vortex on graphene through cross shape nanoantennas under linearly polarized incidence. For each cross shape antenna, the linearly polarized incidence can be coupled to a near-field plasmons vortex on graphene through antenna resonances. When multiple antennas are arranged into a closed circular array, the sign of topological charge of plasmons vortex can be controlled by the linearly polarized direction of incident light with the distribution of absolute field component exhibiting a non-ideal donut profile. The creating of plasmons vortex on graphene may provide new possibilities in various applications, such as the nanoparticles trapping.

Variation in complex mating signals in an "island" hybrid zone between Stenobothrus grasshopper species.

Two grasshopper species Stenobothrus rubicundus and S. clavatus were previously shown to meet in a narrow hybrid zone on Mount Tomaros in northern Greece. The species are remarkable for their complex courtship songs accompanied by conspicuous movements of antennae and wings. We analyzed variations in forewing morphology, antenna shape, and courtship song across the hybrid zone using a geographic information system, and we documented three contact zones on Mount Tomaros. All male traits and female wings show abrupt transitions across the contact zones, suggesting that these traits are driven by selection rather than by drift. Male clines in antennae are displaced toward S. clavatus, whereas all clines in wings are displaced toward S. rubicundus. We explain cline discordance as depending on sexual selection via female choice. The high covariance between wings and antennae found in the centers of all contact zones results from high levels of linkage disequilibria among the underlying loci, which in turn more likely results from assortative mating than from selection against hybrids. The covariance is found to be higher in clavatus‐like than rubicundus‐like populations, which implies asymmetric assortative mating in parental‐like sites of the hybrid zone and a movement of the hybrid zone in favor of S. clavatus.

Microstrip antenna miniaturization with fractal EBG and SRR loads for linear and circular polarizations

In this paper, combination of electromagnetic band gap (EBG) and split-ring resonator (SRR) loads with fractal formation for miniaturization of microstrip antenna is noticed. Here two different shapes of antenna have been studied with two well-known metamaterial structures as parasitic elements. A conventional microstrip antenna, which is surrounded by four EBG unit cells, is chosen as the first antenna. It has an effective resonance at 2.5. The Minkowski fractal method is applied to EBG unit cells in this stage. The Minkowski fractal structure is implemented for accession of effective capacitance in EBG unit cells. The second antenna frequencies are 2.5 and 5.9 GHz. It contains a slot structure with four SRRs, used for making parasitic elements and for achieving multi-band characteristic. The fractal method is used to improve the inductance of SRR structure by increasing the effective length of microstrip line. At this stage, the applied fractal structure has been modified, so that the frequency of wireless application could be achieved. In the last step, by some changes in feed line of the slot antenna, circular polarization (CP) is obtained for the second antenna, which shows that SRR load can be helpful for making the CP.

Production of fuel by co-pyrolysis of Makarwal coal and waste polypropylene through a hybrid heating system of convection and microwaves

Summary The bituminous coal of the Makarwal range of Pakistan and waste polypropylene were converted into gaseous and liquid fuel using a hybrid heating process based on microwave metal interactions. The mixture of coal and polypropylene was heated by the volumetric heating generated by absorption of the microwaves and the conventional heating produced by the sparking of copper under microwave power in a domestic microwave oven. The heat generation capacity and range of sparking of copper were increased by the use of tightly coiled copper antenna. The heat generation efficiency of copper antenna was found to vary with variation in the shape of the copper antenna. Four types of antenna were used in the pyrolysis process, i.e. the antenna made of tightly coiled copper, copper mesh antenna, copper strips antenna and copper cylinder antenna. It was observed that copper coil and copper mesh antenna were more efficient and responsible for higher percent conversions while the multi-strip antenna was next and the least percent conversion was observed for single strip cylinder of copper. The amount of products and the relative concentrations of the oil, wax and gases were observed to vary with variations in the relative amount of coal and polymers. Both the gaseous product and aqueous fraction were analysed for sulphides using lead acetate reagent. The gases were also analysed for the presence of alkynes and alkenes using aqueous solutions of copper-I chloride and potassium permanganate respectively. The oily product which was composed of oil and wax was analysed by GC-FID and GC-MS analyses. Copyright © 2016 John Wiley & Sons, Ltd.

Reinvestigation of the antennal morphology of the white-backed planthopper Sogatella furcifera (Horváth) (Hemiptera: Delphacidae)

Reinvestigation of the antennal morphology of the white-backed planthopper Sogatella furcifera (Horváth), a major pest of rice in Asia, revealed the presence of sensilla and other structures not reported in previous studies of this species. Scanning electron microscopic examination of antennae of males and females confirmed that the antennae of S. furcifera are similar to those of other recently studied species, consisting of scape, pedicel, and flagellum composed of a basal bulb and an apical segmented arista. In contrast to previous studies that only described four types of sensilla, twelve types of sensilla were observed. The scape and pedicel have dispersed sensilla which contain a Böhm bristle, single dome-shaped campaniform sensilla, several sensilla trichodea I and papillae-like sensilla I. A sensilla basoconicum II, several sensilla basiconica I, single sensillum campaniformium II, sensilla trichodea I, sensilla trichodea II, plaque organs, and papillae-like sensilla II occurred on the pedicel. A single sensillum coeloconicum and three sensilla basiconica III are located apically on the posterior surface of the bulb. Sensilla trichodea I were the most abundant and plaque organs were the most conspicuous sensilla, distributed on the pedicel. No differences were observed in antenna shape and basic structure in the males and females. The possible functions of the sensilla are discussed in relation to their morphology and compared to those found in other Fulgoroidea, especially Delphacidae. The external morphology, distribution, and abundance of sensilla located on the antennae of S. furcifera are illustrated, with a brief discussion of their taxonomic, phylogenetic, and putative functional significance.

Room temperature strong light-matter coupling in three dimensional terahertz meta-atoms

We demonstrate strong light-matter coupling in three dimensional terahertz meta-atoms at room temperature. The intersubband transition of semiconductor quantum wells with a parabolic energy potential is strongly coupled to the confined circuital mode of three-dimensional split-ring metal-semiconductor-metal resonators that have an extreme sub-wavelength volume (λ/10). The frequency of these lumped-element resonators is controlled by the size and shape of the external antenna, while the interaction volume remains constant. This allows the resonance frequency to be swept across the intersubband transition and the anti-crossing characteristic of the strong light-matter coupling regime to be observed. The Rabi splitting, which is twice the Rabi frequency (2ΩRabi), amounts to 20% of the bare transition at room temperature, and it increases to 28% at low-temperature.

Broadband and 28/38-GHz Dual-Band Printed Monopole/Elliptical Slot Ring Antennas for the Future 5G Cellular Communications

The mobile industry has seen significant growth; it evolved from analog to digital second generation (2G) Global System for Mobile (GSM), then to high-data rate cellular wireless communication such as third generation (3G) Wideband Code Division Multiple Access (WCDMA), and further to packet optimized 3.5G High Speed Packet Access (HSPA) and fourth generation (4G) Long-Term Evolution (LTE) and LTE advanced systems [1]. The 4G wireless communication systems have been deployed in many countries. However, with the widespread use of wireless devices and mobile services, there are still some challenges that cannot be absorbed until the 4G, such as the spectrum crisis and high-energy consumption [2]. The race to search for innovative solutions to enable the fifth generation (5G) wireless communication networks era has begun. Once developed, the 5G network will permit gigabitper-second transmission on compatible mobile devices. 5G is expected to meet the requirements to enable higher capacity, higher rate, more connectivity, higher reliability, lower latency, greater versatility, and application domain-specific topologies. New concepts and design approaches are in dire need. Future 5G will most likely use millimeter-wave frequencies. Beamforming could be one of the solutions for the future 5G cellular communications. Theoretical feasibility and prototype results for millimeter-wave (mmWave) beamforming as an enabling technology for 5G cellular communications have been discussed in [3]. Achieving higher data rates with mmWave beamforming for next generation communications is proposed in [4]. Author has contributed in designing several slot/monopole antenna designs for ultrawideband (UWB) applications [5–15]. Different monopole antenna shapes with ultra-wide bandwidth have been proposed in [5–7]. An elliptical slot antenna with elliptical shaped microstrip-line fed radiator for UWB operation has been introduced in [5]. Another monopole antenna with a trapezoidal shaped patch with two elliptical shaped cuts from its edge forming a J Infrared Milli Terahz Waves (2016) 37:308–317 DOI 10.1007/s10762-016-0252-2

Simulation and Performance Analysis of Carbon Nano-materials based Patch Antennas

In this paper, rectangular and circular shape antennas are designed for analyzing the performance characteristics of an antenna. Semiconducting Carbon Nanotube (CNT), Metallic Carbon Nanotube (MCNT), Copper and Graphene are considered as the patch materials. There are different parameters but conductivity has been taken to differentiate between these patch materials. Each patch material has its own conductivity through which a comparative analysis has been implemented in this paper. Different types of parameters like Return loss, Gain, Voltage Standing Wave Ratio (VSWR) and Radiation pattern are obtained and discussed to analyze the results. Resonant frequency for the metallic CNT rectangular patch antenna has been noticed at 2.85 GHz. Resonant frequencies of 2.87 GHz and 2.88 GHz has been obtained for Copper and Graphene patch antenna in rectangular shape. Comparison of simulated results has been obtained in the same manner for circular shape antenna. A resonant frequency of 18.74 GHz has been noticed for patch antennas in circular shape. On comparing the simulated results, Graphene patch antennas has been observed to deliver best performance.

RF power absorption by plasma of a low-pressure inductive discharge

This paper aims to analyze the mechanism of power absorption and to reveal, both experimentally and numerically, the basic factors determining the ability of plasma to absorb RF power. This is done by determining the plasma equivalent resistance value under different conditions in a low-pressure RF inductive discharge such as different antenna shape, working gas pressure, electron density, operating frequency and geometrical dimensions of the plasma source. Experimental and numerical results show that the plasma equivalent resistance changes non-monotonously with an increase in electron density, increases with an increase in neutral gas pressure, and that the maximum plasma equivalent resistance shifts toward higher electron densities when the operating frequency is increased.

A Design of Vehicular GPS and LTE Antenna Considering Vehicular Body Effects

In this paper, a vehicular antenna design scheme considering the vehicular body effects is proposed. A wire antenna for GPS and LTE is implemented on the plastic plate, then it is mounted on the front glass. The outputs are commonly used to share the feed. It is necessary for GPS to increase the right hand circularly polarization (RHCP) gain near the zenith and to reduce the axis ratio while for LTE to increase the horizontal and vertical polarization (HP and VP) gain in the horizontal plane. Also for LTE, multiband characteristics are required. In order to achieve the specified performance, the antenna shape is optimized by Parato genetic algorithm (PGA). When the antenna is mounted on the body, the performance is seriously changed. To evaluate performance of the antenna mounted on the body with a complex shape, a commercial electromagnetic simulator (Ansoft HFSS) is used. To apply electromagnetic results output by HFSS to PGA algorithm operating on the MATLAB, MATLAB to HFSS linking program via Visual BASIC (VB) script was used. It is difficult to carry out the electromagnetic analysis with the whole body because of limitations of the calculating load and memory size. To overcome the limitation, we consider only a predominant part where it has an influence on the performance. It is presented that degradations caused by the body are improved through a series of optimization stages. The simulation results obtained clearly show that it is well optimized at 1.575 for GPS and 766.5 MHz and 2.135 GHz for LTE, respectively.

A Novel Multiphysics Optimization-Driven Methodology for the Design of Microwave Ablation Antennas

Microwave ablation is based on localized heating of biological tissues, enabled by an electromagnetic field. Ablation antennas are commonly designed in a forward approach, where the shape and type of antenna are manipulated to generate elevated temperatures in the target region. However, little attention has been dedicated to designing antennas in an inverse approach to allow controlled synthesis of temperature profiles customized for the application, in a reconfigurable way. Also, existing designs are based on generating a particular electric field or SAR profiles, not accounting for discontinuities in the thermal conductivity of tissue. We propose an inverse multiphysics strategy for source design that involves optimizing the current distribution on the antenna to synthesize a desired temperature profile, while accounting for temperature diffusion. We apply this optimization procedure to a simulated test case in human liver and study the associated fields and temperature profiles, as well as the optimized current distributions required. Our results indicate and quantify the clear advantage of this multiphysics approach compared to electric field focusing in terms of meeting objectives in the thermal domain. We show how the optimized current distributions can be easily implemented in a practical design and integrated into treatment planning in a clinical setting.

Design of Hexagon Shape Bow-Tie Patch Antenna for Implantable Bio-Medical Application

In this paper presents the patch antenna in the shape of hexagon bow-tie antenna for implantable bio-medical application in the frequency range of 2.4–2.48GHz ISM (industrial, scientific and medical) band. The patch antenna designed with CPW feed for high frequency response. The proposed system is designed with the material of Alumina ceramic substrate (Al2O3), the value of dielectric constant is 9.8 with thickness of 1mm. The total size of the antenna is 10*10*1 mm. The main advantage of proposed system is it consumes very low size and the accuracy of the system is increased. The designed antenna is analyzed with human tissues like skin, fat and muscle and the parameters of the antenna like return loss, VSWR, radiation pattern and gain etc, are measured. The return loss of proposed antenna is-29dB achieved. So the proposed hexagon shape bow-tie antenna is used for several implantable applications.

A Defected Structure Shaped CPW-Fed Wideband Microstrip Antenna for Wireless Applications

A coplanar waveguide (CPW) fed compact wideband defected structure shaped micro-strip antenna is proposed for wireless applications. Defected structure is produced by cutting the shape antenna in the form of two-sided T shape. The proposed antenna consists of two-sided shape strip as compared to usual monopole patch antenna for minimizing the height of the antenna. The large space around the radiator is fully utilized as the ground is on the same plane as of radiator. Micro-strip line feed is used to excite the proposed antenna placed on an FR4 substrate (dielectric constant). The antenna is practically fabricated and simulated. Simulated results of the proposed antenna have been obtained by using High-Frequency Structure Simulator (HFSS) software. These results are compared with measured results by using network analyzer. Measured result shows good agreement with the simulated results. It is observed that the proposed antenna shows a wideband from 2.96 GHz to 7.95 GHz with three bands.

Development of computational model for tunable characteristics of graphene based triangular patch antenna in THz regime

Design of antennas in terahertz regime demands for efficient design methodologies as miniaturization limits the performance in terms of higher geometric uncertainty, improper characterization of the antenna leading to fabrication difficulties. New material such as graphene having a number of desirable electromagnetic and mechanical properties can play a significant role in overcoming the limitations for miniature antenna using a well defined shape of antenna while maintaining the key antenna parameters like return loss, gain, directivity, VSWR, radiation pattern and radiation efficiency. The equilateral triangular patch antenna has been designed here using graphene as the patch conductor. The design procedure presented in this paper incorporates the electrical and non-electrical properties of graphene for initializing the tunable conductivity which is further coupled to electromagnetic simulator for analyzing the radiation properties of the graphene antenna. The mathematical modeling of the antenna is performed using ANSYS Maxwell and high frequency simulation software. The tunable characteristics of the antenna are validated from return loss and radiation plots. Sufficient radiation efficiency is achieved at resonant frequencies in the range 1---3 THz. The antenna absorption cross section variations due to tunable surface conductivity owing to applied bias voltages is also analyzed.

Design and Performances of Implantable CPW Fed Apollian Shaped Antenna at 2.45 GHz ISM Band for Biomedical Applications

Design and Performances of Implantable CPW Fed Apollian Shaped Antenna at 2.45 GHz ISM Band for Biomedical Applications