Improving the performances of triangular microstrip antenna with multilayered configuration

2013 ◽  
Vol 33 (1/2) ◽  
pp. 337-354 ◽  
Author(s):  
Ouarda Barkat
Keyword(s):  
Integral Equation ◽  
Electric Field ◽  
Microstrip Antenna ◽  
Single Layer ◽  
Microstrip Antennas ◽  
Air Gap ◽  
Air Separation ◽  
Method Of Moment ◽  
Content Type ◽  
Cover Layer

Purpose – An improved analytical model is presented to investigate the scattering properties of high Tc superconducting triangular antennas in multilayered configuration. The spectral method is used to study the scattering properties of superconducting triangular antennas. Galerkin method is used in the resolution of the electric field integral equation. The boundary condition for the electric field was used to derive an integral equation for the electric current. To validate the theoretical results, a study has been performed for perfectly conducting triangular patch on a single layer, with air gap, and cover layer. The computed data are found to be in good agreement. The paper aims to discuss these issues. Design/methodology/approach – A spectral domain approach has been used for the numerical calculation of the characteristics of a high Tc superconducting microstrip antenna with an air gap and cover layer. Initially, the authors use an integral method of moment which enabled them to exploit the spectral tensor of green. The resolution of the integral equations of the electric field by the procedure of Galerkin makes it possible to lead to a system of equations homogenous. The authors have calculated the frequency of resonance and the radiation pattern of antenna. Findings – The properties of the HTSTMA structure were stable at temperatures slightly lower than the critical temperature. Also computations show that the air separation can be adjusted to have the maximum operating frequency of the superconducting microstrip antenna. On the other hand, the bandwidth increases monotonically with increasing the air gap width. Therefore, HTS materials do offer efficiency improvements for antenna systems that can accommodate the added constraints of the superconducting environment. The calculated results have been compared with measured one available in the literature and excellent agreement has been found. Originality/value – To the best of the authors' knowledge, this subject has not been reported in the open literature; the only published results on the analysis of perfectly conducting triangular microstrip antennas.

scholarly journals ANN Synthesis Model of Single-Feed Corner-Truncated Circularly Polarized Microstrip Antenna with an Air Gap for Wideband Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Zhongbao Wang ◽  
Shaojun Fang
Keyword(s):  
Computer Aided Design ◽  
Microstrip Antenna ◽  
Microstrip Antennas ◽  
Air Gap ◽  
Training Data ◽  
Data Sets ◽  
Circularly Polarized ◽  
Artificial Neural Network Ann ◽  
Aided Design ◽  
Lm Algorithm

A computer-aided design model based on the artificial neural network (ANN) is proposed to directly obtain patch physical dimensions of the single-feed corner-truncated circularly polarized microstrip antenna (CPMA) with an air gap for wideband applications. To take account of the effect of the air gap, an equivalent relative permittivity is introduced and adopted to calculate the resonant frequency andQ-factor of square microstrip antennas for obtaining the training data sets. ANN architectures using multilayered perceptrons (MLPs) and radial basis function networks (RBFNs) are compared. Also, six learning algorithms are used to train the MLPs for comparison. It is found that MLPs trained with the Levenberg-Marquardt (LM) algorithm are better than RBFNs for the synthesis of the CPMA. An accurate model is achieved by using an MLP with three hidden layers. The model is validated by the electromagnetic simulation and measurements. It is enormously useful to antenna engineers for facilitating the design of the single-feed CPMA with an air gap.

Simulation on motion characteristics of space charge in single oil-paper insulation

2017 ◽  
Vol 36 (6) ◽  
pp. 1663-1675 ◽  
Author(s):  
Zhifei Yang ◽  
Zhiye Du ◽  
Jiangjun Ruan ◽  
Shuo Jin ◽  
Guodong Huang ◽  
...  
Keyword(s):  
Electric Field ◽  
Space Charge ◽  
Electric Field Intensity ◽  
Single Layer ◽  
Simulation Method ◽  
Insulation System ◽  
Content Type ◽  
Space Charges ◽  
Paper Insulation ◽  
Total Electric Field

Purpose The purpose of this paper is numerical calculation of total electric field in oil-paper insulation. Now, there is no effective method to consider the influence of space charges when calculating the total electric field distribution in the main insulation system of the valve-side winding of an ultra-high-voltage direct current converter transformer. Design/methodology/approach To calculate the total electric field in an oil-paper insulation system, a new simulation method in single-layer oil-paper insulation based on the transient upstream finite element method (TUFEM) is proposed, in which the time variable is considered. The TUFEM is used to calculate the total electric field in an oil-paper insulation system by considering the move law of space charges. The simulation method is verified by comparing the simulation results to the test data. The move law of space charges and distribution characteristics of the electric field under difference voltage values in single-layer oil-paper insulation were presented. Findings The results show that the TUFEM has an excellent accuracy compared with the test data. When carrier mobility is a constant, the time to reach the steady state is inversely correlated with the initial electric field intensity, and the distortion rate of the internal total electric field is positively correlated with the initial electric field intensity. Originality/value This paper provides an exploratory research on the simulation of space charge transport phenomenon in oil-paper and has guiding significance to the design of oil-paper insulation.

scholarly journals Single-Layer Line-Fed Broadband Microstrip Patch Antenna on Thin Substrates

Electronics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 37
Author(s):  
Roberto Vincenti Gatti ◽  
Riccardo Rossi ◽  
Marco Dionigi
Keyword(s):  
Patch Antenna ◽  
State Of The Art ◽  
Low Cost ◽  
Single Layer ◽  
Microstrip Antennas ◽  
Microstrip Patch Antenna ◽  
Layer Line ◽  
Limited Bandwidth ◽  
Microstrip Patch ◽  
Effective Design

In this work, the issue of limited bandwidth typical of microstrip antennas realized on a single thin substrate is addressed. A simple yet effective design approach is proposed based on the combination of traditional single-resonance patch geometries. Two novel shaped microstrip patch antenna elements with an inset feed are presented. Despite being printed on a single-layer substrate with reduced thickness, both radiators are characterized by a broadband behavior. The antennas are prototyped with a low-cost and fast manufacturing process, and measured results validate the simulations. State-of-the-art performance is obtained when compared to the existing literature, with measured fractional bandwidths of 3.71% and 6.12% around 10 GHz on a 0.508-mm-thick Teflon-based substrate. The small feeding line width could be an appealing feature whenever such radiating elements are to be used in array configurations.

Does corporate governance affect the performance of Islamic banks? New insight into Islamic countries

2020 ◽  
Vol 20 (6) ◽  
pp. 1073-1090 ◽  
Author(s):  
Ejaz Aslam ◽  
Razali Haron
Keyword(s):  
Corporate Governance ◽  
Audit Committee ◽  
Positive Impact ◽  
Islamic Banks ◽  
Governance Mechanism ◽  
Method Of Moment ◽  
Content Type ◽  
Return On Equity ◽  
Islamic Countries ◽  
And Performance

Purpose Corporate governance plays a significant role to overcome agency issues and develop the culture of transparency and openness. In this context, this paper aims to examine how corporate governance mechanisms affect the performance of Islamic banks (IBs). Design/methodology/approach Stepwise, two-step system generalize method of moment estimation technique is used in the analysis in which control variables are added into the model sequentially. This study used data on 129 IBs from 29 Islamic countries (Middle East, South Asia and Southeast Asia) during the period of 2008 to 2017. Findings The findings suggest that the audit committee (AUDC) and Shariah board (SB) have positive impact on the performance of IBs (return on assets and return on equity). However, board size and risk management committee have negative and significant effect on the performance of IBs. CEO duality and non-executive directors have mixed relationship with the performance of IBs. These results support the argument that IBs need to improve their financial performance through appropriate governance mechanism. Research limitations/implications The findings of the study added a new dimension to the governance research that could be a valuable source of knowledge for policymakers and regulators to improve the existing governance mechanism for better performance of IBs. Originality/value The study fills the gap in the literature by addressing the issue of corporate governance on performance of IBs across countries. Agency theory is discussed to explain the relationship between corporate governance mechanism and performance.

Sign in / Sign up

Export Citation Format

Share Document