Síntese e Caracterização do BaTiO3 pelo Método da Coprecipitação e Aplicação em Antenas Patch de Microfita

RESUMO O nosso objetivo foi sintetizar e caracterizar o Titanato de Bário (BaTiO3) para aplicação em substrato dielétrico em antenas patch de microfita. O surgimento de novas tecnologias sem fio resulta em demandas crescentes por antenas de baixo custo que permitam a união de diferentes tecnologias em um único dispositivo portátil. BaTiO3, composto cerâmico com estrutura cristalina do tipo perovskita (ABO3), encaixa-se na classe de cerâmicas eletrônicas e pode ser utilizado na forma de filme fino, para composição de componentes de memória RAM de computadores, devido a polarização espontânea reversível. As antenas de microfita constitui-se de um substrato dielétrico onde uma das faces é impresso um condutor radiante ou patch e na outra face, um plano terra. Há vários métodos para sintetizar o BaTiO3, todavia nesta pesquisa foi sintetizado por coprecipitação, a partir do Acetato de Bário (BaC4H6O4), Dióxido de Titânio (TiO2) e Ácido Nítrico (HNO3). Após síntese, foi caracterizado por Difração de Raios X com refinamento pelo método de Rietveld, onde obteve-se a fase tetragonal, na qual o BaTiO3 possui ferroeletricidade, além de medidas de Densidade (5,698 g/cm3), Porosidade (5,31 %) e Microscopia Eletrônica de varredura, cujo constatou uma distribuição granular homogênea com tamanho médio do cristalito de 500 nm. Além disso, simulou-se uma antena no Ansoft HFSS® para aplicação na faixa de 6.5 GHz, obtendo-se uma largura de banda de 240 MHz. O método de síntese por coprecipitação se mostrou eficiente e a antena promissora para aplicações em sistemas wireless.

The the design of the microstrip array antenna with the rosette patch for WLAN 2.4 GHz and 5.2 GHz frequencies

This research discusses the design of the microstrip array antenna with the rosette patch model that works on WLAN 2.4 GHz and 5.2 GHz frequencies which are used for WIFI networks. This microstrip antenna is made using a feedline feed or direct feed with a directional radiation pattern. The initial design used Ansoft HFSS v.13. Software, then fabricated the Microstrip Antenna using a PCB with a single layer FR4 type, and consisted of a patch, substrate, and groundplane. This antenna has dimensions of 94 mm in length and 63.3 mm in width. The measurement results in Laboratorium obtained VSWR 1.6, return loss -12.817, and 31.357 impedance, at a frequency of 2.4 GHz. While at a frequency of 5.2 GHz the VSWR value is 1.292, return loss is -18,210, and impedance is 46.417.

Simulation of electromagnetic field distribution in the measuring cell for determining the dielectric permittivity of materials at microwave frequencies

To determine the dielectric permittivity of materials in a wide frequency range with the automation of measurements and the necessary accuracy, measuring cells have been created to ensure the simplicity of the design of the waveguide path. In order to obtain information about the suitability of measuring cells based on irregular SHF waveguides for estimation of dielectric parameters of materials, we simulated the structure of electromagnetic field in the system consisting of two irregular waveguides and waveguide chamber placed between them using a three-dimensional electrodynamic simulation in Ansoft HFSS package environment. The distribution of the electric field was simulated when an empty polyethylene tube, a rod of fluoroplastic and a rod of textolite are placed in the measuring cell. It was demonstrated that high order modes fade out in irregular waveguide and do not affect the precision of obtained results, and significant edge effects were not detected. It allows one to utilize measuring cells based on irregular waveguides together with a scalar or vector network analyzer and using the partial filling of the waveguide method or the modified Nicholson – Ross – Weir method for measurements of dielectric permittivity  of materials. The results of modeling the dependence of the amplitude and phase of the reflection coefficient of the textolite and fluoroplastic on the frequency in Ansoft HFSS environment are given. The simulation results are compared with the results obtained experimentally. The frequency dependencies of  were obtained experimentally for test materials – textolite and fluoroplastic – in the frequency range of 25,95–37,50 GHz. The experimental data are in satisfactory agreement with the results of theoretical calculations and do not go beyond the boundaries specified by the measurement uncertainty.

Heptagonal Shaped UWB Antenna with DGS for Wireless LTE with Enhanced Bandwidth

The paper discusses about the implementation of Heptagonal shaped compact ultra-wideband planar Microstrip patch antenna with and without defected ground plane structure (DGS) with analysis of various parameters like return loss, VSWR bandwidth etc. A substrate made up of dielectric constant FR4 epoxy is utilized and the 2D and 3D radiation pattern are also discussed. DGS has helped to fine tune and increase the bandwidth & its effects have been studied. A volume of 28x32x1.7 (1523.2 mm^3) is occupied by the size of antenna with dielectric constant of εr = 4.4, tanδ= 0.02. In order to provide fine tuning in the return loss graph, a 50Ω line with width of W=3mm direct line feeding method has been used for the micro-strip line and slots have been introduced in the ground plane structure, for achieving the good bandwidth coupling between the slots plays an important role. The antenna parameters including VSWR, Gain and return losses v/s frequency effects for the antenna with variation of slots and dimensions has been studied in this paper along with the analysis of important parameters such as return loss (dB), bandwidth, VSWR (Voltage Standing Wave Ratio) of patch antenna which has been performed using Ansoft HFSS v15 tool. The proposed design of the heptagonal shaped antenna operates as an ultra-wide band antenna ranging from 3.20 GHz to 10 GHz and beyond covering most of applications from LTE, Wimax (3.5/5.55GHz), Radio altimeter, RFID and ISM WLAN 5.2/5.8GHz etc

Compact Ultra-wide-band Bandpass Filter using Square Complimentary Split Ring Resonator

Background: In this paper, an ultra-wide-band bandpass filter with large stopband using interdigital coupled lines and pair of Square Complimentary Split Ring Resonator (SCSRR) is proposed. Methods: Interdigital coupled lines give bandpass characteristics and pair of SCSRR provides tuning of cut off frequencies and transmission zeroes on both side of the passband. In the passband, two transmission poles are achieved. The tightly coupled structure provides a wide stopband and sharp skirt response. Results: Dielectric constant 2.6 and its thickness of 0.787 mm is used to implement the design. Centre frequency of the proposed design is 5.1 GHz. Bandwidth at -3 dB is 3.5 GHz to 6.5 GHz. Conclusion: The proposed structure is simulated in Ansoft HFSS.

Ultra Wide Band Dielectric Rod Antenna

Introduction. Often, the space allocated for placement of an antenna has an inconvenient shape for this. The inconvenience is that its overall dimensions, namely the length and height, relate to each other approximately as 5:1. The task of placing the antenna in the space, in the absence of ready-made solutions, involves the development of an antenna with a similar ratio (5:1) of overall dimensions and with the possibility of convenient mounting on a flat conductive surface. Also, in the 9:1 frequency band, the antenna should have the following radio technical characteristics: voltage standing wave coefficient (VSWR) of not more than 3, gain of at least 1 dBi, radiation patterns should be axisymmetric with side lobe level not exceeding 25 %.Aim. Development and study of the characteristics of an ultra-wideband dielectric rod antenna.Materials and methods. Two structurally different versions of an ultra-wideband dielectric rod antenna were proposed. The main radio technical characteristics of both options were obtained through electrodynamic modeling in Ansoft HFSS.Results. As a result of the simulation, the following radio characteristics were obtained: – for the first option, the VSWR does not exceed 3.25 in the required frequency range, the gain varies from 6 to 12 dBi, the axisymmetric radiation patterns with the level of the side lobes not exceeding 30 %; – for the second option, the VSWR does not exceed 2.75 in the required frequency range, the gain varies from 5 to 11 dBi, the axisymmetric radiation patterns with the level of the side lobes not exceeding 20 %; In addition, the structural differences of the second option make it convenient to fix it on a flat conductive surface.Conclusion. Comparison of the obtained results with the requirements for the antenna under consideration shows that, unlike the first, the second option has an acceptable level of matching (VSWR 2.75) and of side radiation of radiation patterns (20 %). Based on this, it can be concluded that only the second option is suitable for the intended application.

A Naval Analysis of Microstrip Antenna Array using Various Elements for ISM-Band

Right now, point is to contrast single fix receiving patch and 1x2 exhibit and 1 x4 radio patch on FR4. The emphasis will be on upgrading the elements of fix reception apparatus additionally kept up a high increase in the ISM band (2.3 GHz to 2.6 GHz) at focus recurrence 2.45 GHz. Various parameters of reception apparatus like VSWR, return loss, increase gain and radiation design are reproduced utilizing Ansoft HFSS programming v13. Microstrip patch radio wire in remote correspondence is picking up significance as a most impressive mechanical pattern. Its enormous potential guarantees huge change in close to term eventual fate of remote application fields. The current innovative pattern has concentrated on microstrip patch radio wire. Single microstrip patch reception apparatus has a few favorable circumstances (ease, lightweight, conformal and low profile), however, it has little detriments too-like low addition, low productivity, low directivity, and thin data transfer capacity. These weaknesses can be overwhelmed by the execution of many fix reception apparatuses in a cluster design. Here term exhibit represents geometrical and electrical courses of action of fix components. As we increment the number of patch components to frame a cluster, improvement in execution is watched. Right now, for 1x1, 1x2, 1x4 clusters have been investigated and thought about. It has been inferred that the 1x4 patch cluster shows a preferable outcome over a single patch.

Experimental Verification of LG WAVE and Ansoft HFSS Simulation Software Using a 2 x 2 Antenna Array with EBG Structure

In this paper we are presenting the validation of the LG RF Simulation tool (WAVE) and HFSS simulation software’s through measurement results of the fabricated design, simulated in WAVE and HFSS simulation software’s. A 2 x 2 antenna array with Electromagnetic Band Gap (EBG) structure in the ground plane is simulated using WAVE and HFSS ver. 17.The prototype antenna was fabricated and characterization is carried out at CHRIST (Deemed to be University) Bangalore to know the performance of the antenna array. Return Loss and VSWR of the fabricated antenna are measured using Anritsu S820E Microwave Site Master Network Analyzer. Two - dimensional radiation patterns were plotted and compared with the simulated results obtained from WAVE and HFSS Software’s. From the results of HFSS simulation software we observed that EBG integrated array is exhibitinggainof7.089dB and Return loss of -16.2 dBat2.4GHz.Whereas the results obtained from WAVE simulation tool for the same design gave a peak gain of 5.03 dB and return loss of -12.8dB at 2.4 GHz. Measured gain of the designed array is 7.407 dB and return loss is -7.565 dB at 2.4 GHz.

A Double Combined Symmetric T-shaped Slots and Rotated L-shaped Strips Inspired UWB Antenna for C and X-band Elimination Filters

In this paper, we present a modified UWB antenna with hexagonal slotted ground plane inspired with a double combined symmetric T-shaped slots and dual rotated L-shaped strip for dual band notched characteristics. Initially, the operating frequency range is from 3GHz to 12 GHz. To eliminate the unwanted C-band (3.625-4.2GHz) and the entire uplink and downlink of X-band satellite communication systems (7.25 -8.39 GHz) frequency bands, we are investigating the conventional UWB patch antenna and loaded it with a mentioned strips and slots respectively. The performances of the antenna are optimized both by CST Microwave Studio and Ansoft HFSS. To further analyze the parametric effects of the slots and strips, the surface current distribution is presented and discussed. The antenna gain versus frequency gives an acceptable value except the notched band regions, these values are reduced from its normal to be a negative in the notched bands (3.625-4.2GHz) and (7.25 to 8.39 GHz).

Perancangan dan Analisis Antena Dipole Pada Frekuensi 2,4 GHz Untuk Modul Xbee S2 Pro Menggunakan HFFS 14.0

Xbee s2 pro module works at 2,4 Ghz using IEEE 802.15.4 standard and polarization are linear. There are many types of antennas that can be used, which one is the dipole antenna. The simulation model implemented in this study uses Ansoft HFSS 14.0 software. HFSS stands for high frequency structure simulator is a pioneer in the use of finite element method for electromagnetic wave simulators that implement tangential vector finite elements, adaptive meshing and Adaptive Lanczos-Pade Sweep (ALPS) technology. By using HFSS 14.0 simulation, the axial ratio value of 35.0359 dB that means linier polarization. For the value of s-parameter -21,1851 db and VSWR value approaches 1, that is 1.5195 db. The gain value obtained is 0.7469 dB, the gain value needs to be optimized by using a metamaterial to get a good gain.