Radiation Pattern Synthesis and Mutual Coupling Compensation in Spherical Conformal Array Antennas

2021 ◽  
Vol 36 (6) ◽  
pp. 707-717
Author(s):  
Taimur Khan ◽  
Muhammad Khattak ◽  
Adnan Tariq
Keyword(s):  
Radiation Pattern ◽  
Mutual Coupling ◽  
Surface Deformation ◽  
Spherical Shape ◽  
Least Square ◽  
Spatial Distance ◽  
Main Beam ◽  
Antenna Gain ◽  
Pattern Synthesis ◽  
Conformal Array

This paper presents a novel technique based on Hybrid Spatial Distance Reduction Algorithm (HSDRA), to compensate the effects of deformity and mutual coupling occurred due to surface change in conformal arrays. This antenna surface deformation shifts the position of null points and loss of the main beam resulting in reduced antenna gain along with substantial undesirable effects on the antenna performance. The proposed algorithm, which cumulatively incorporates the Linearly Constraint Least Square Optimization (LCLSO) and Quadratically Constraint Least Square Optimization (QCLSO) techniques, is formulated to minimize/reduce the absolute distance between the actual (simulated/measured) radiation pattern and the desired radiation pattern while keeping the direction of main beam and nulls position under control. In particular, a 4x4 conformal microstrip phased array from planar surface is deformed to prescribe spherical-shape surface with various radii of curvature, is validated. For the enhancement of Gain of the conformal array antenna, Gain Maximization Algorithm is also proposed, the simulated results of which is compared to the traditional Phase compensation technique and unconstraint least squares optimization. The analytical results for both planar and spherical deformed configurations are first evaluated in MATLAB and then validated through Computer Simulation Technology (CST).

scholarly journals Conformal Array Pattern Synthesis Using a Hybrid WARP/2LB-MOPSO Algorithm

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Roghieh Karimzadeh Baee ◽  
Keyvan Forooraghi ◽  
Somayyeh Chamaani
Keyword(s):  
Degrees Of Freedom ◽  
Mutual Coupling ◽  
Side Lobe ◽  
Penalty Functions ◽  
Main Beam ◽  
Side Lobe Level ◽  
Initial Population ◽  
Pattern Synthesis ◽  
Conformal Array ◽  
Multiobjective Particle Swarm Optimization

This paper addresses conformal array synthesis as a constrained multiobjective optimization problem. Simultaneous reduction of side lobe level (SLL) and cross-polarization (XPL) level is aimed with a constraint on main beam direction. A hybrid of weighted alternating reverse projection (WARP) and two local best multiobjective particle swarm optimization (2LB-MOPSO) is proposed to optimize the pattern. First, the WARP method finds a moderate and feasible solution. Second, 2LB-MOPSO begins with an initial population including the solution of WARP and penalty functions for constraint handling. Involving WARP result in the initial population of 2LB-MOPSO leads to higher convergence rate, avoiding local extermum traps and less sensitivity to penalty functions. Compared to WARP method which stagnates rapidly, the proposed hybrid method gives better SLL and XPL after adequate iterations. In addition, as 2LB-MOPSO offers a set of optimum solutions (Pareto front) instead of a single solution, this method provides more degrees of freedom in selection of proper practical arrays. Finally, to examine the mutual coupling consideration in array design, the same procedure was applied ignoring the mutual coupling between elements. The results show that the SLL and XPL strongly depend on mutual coupling.

scholarly journals Mutual Coupling Effects Analysis in a Cross-Rhombic Antenna Array

2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Jorge Sosa-Pedroza ◽  
Luis Carrión-Rivera ◽  
Sergio Peña-Ruiz ◽  
Fabiola Martínez-Zuñiga
Keyword(s):  
Antenna Array ◽  
Radiation Pattern ◽  
Mutual Coupling ◽  
Coupling Effects ◽  
Conformal Array ◽  
Wave Simulation ◽  
Full Wave ◽  
The One ◽  
Hexagonal Pyramid ◽  
Numerical Approaches

We present an analysis of mutual coupling effects on radiation pattern and individual coupling in a conformal array of cross rhombic antennas. Analysis is made using both full-wave simulation and numerical approaches implemented in Matlab. The array consists of a truncated hexagonal pyramid, with a cross rhombic antenna in each pyramidal face, including the one on the top, having a 7-antennas-array. Results of radiation pattern and S11 parameters are presented, showing mutual coupling effects among the elements.

Perbandingan Desain Antena Dipole dan Yagi-Uda Menggunakan Material Aluminium pada Frekuensi 470 – 890 MHz

2017 ◽  
Vol 3 (3) ◽  
pp. 140
Author(s):  
Suci Rahmatia ◽  
Putri Wulandari ◽  
Nurul Khadiko ◽  
Fitria Gani Sulistya
Keyword(s):  
Radiation Pattern ◽  
Daily Activity ◽  
Dipole Antenna ◽  
Antenna Gain ◽  
Communication Tool ◽  
Dipole Antennas ◽  
Gain Bandwidth ◽  
Large Gain ◽  
At Home

<p><em>Abstrak </em><strong> - Antena merupakan alat pemancar yang akrab dengan aktifitas sehari-hari dan mudah sekali dijumpai, di rumah, di gedung, bahkan pada alat komunikasi yang digunakan. Salah satu antena yang sering digunakan adalah antena televisi. Antena televisi yang sering digunakan adalah Yagi-Uda yang biasanya dipakai sebagai outdoor antena dan antena dipole yang biasanya digunakan untuk indoor antena. Masing – masing jenis antena memiliki kriteria dan keuntungan berdasarkan dari kebutuhan penggunaannya. Baik antena dipole maupun antena Yagi-Uda memiliki perbedaan diantaranya adalah besar bandwidth, nilai gain, dan pola radiasi. Pada paper ini dapat diketahui bahwa bandwidth yang dimiliki antena yagi-uda lebih besar daripada antena dipole yakni 0.39943 MHz untuk antena yagi-uda dan 0.16569 MHz untuk antena dipole. Begitupula dengan besar Gain yang dimiliki antena Yagi-Uda (6.64 dBi) lebih besar dibandingkan dengan gain dari antena dipole (2.29 dBi). Perbedaan ini dikarenakan faktor elemen director dan ketebalannya.</strong></p><p><strong><br /></strong></p><p><strong><em>Kata Kunci</em></strong> – <em>Atena Televisi, Atena Yagi-Uda, Atena Dipole, Gain, Bandwidth</em></p><p><em> </em></p><p><em>Abstract</em> <strong>- Antenna is a transmitter tool that is familiar with daily activity and easy to find at home, in the building, even on the communication tool used. One of antenna that is often used is a television antenna. Television antennas are often used is Yagi-Uda which is usually used as an outdoor antenna and dipole antenna that is usually used for indoor antennas. Each type of antenna has the criteria and advantages based on the needs of its use. Both dipole antennas and Yagi-Uda antennas have differences among them are bandwidth, gain, and radiation pattern. In this paper it can be seen that the bandwidth of yagi-uda antenna is bigger than dipole antenna that is 0.39943 MHz for Yagi-Uda antenna and 0.16569 MHz for dipole antenna. Neither the large Gain of the Yagi-Uda antenna (6.64 dBi) is greater than the gain of the dipole antenna (2.29 dBi). This difference is due to element factor of director and its thickness.</strong></p><p><strong><br /></strong></p><p><strong><em>Keywords</em></strong><strong> – </strong><em>Television Antenna, Yagi-Uda Antenna, Dipole Antenna, Gain, Bandwidth</em><strong> </strong></p>

scholarly journals Constructing Adaptive Deformation Models for Estimating DEM Error in SBAS-InSAR Based on Hypothesis Testing

2021 ◽  
Vol 13 (10) ◽  
pp. 2006
Author(s):  
Jun Hu ◽  
Qiaoqiao Ge ◽  
Jihong Liu ◽  
Wenyan Yang ◽  
Zhigui Du ◽  
...  
Keyword(s):  
Time Series ◽  
Hypothesis Testing ◽  
Surface Deformation ◽  
A Priori ◽  
Least Square ◽  
Deformation Model ◽  
Phase Time ◽  
Testing Theory ◽  
Sbas Insar ◽  
Deformation Models

The Interferometric Synthetic Aperture Radar (InSAR) technique has been widely used to obtain the ground surface deformation of geohazards (e.g., mining subsidence and landslides). As one of the inherent errors in the interferometric phase, the digital elevation model (DEM) error is usually estimated with the help of an a priori deformation model. However, it is difficult to determine an a priori deformation model that can fit the deformation time series well, leading to possible bias in the estimation of DEM error and the deformation time series. In this paper, we propose a method that can construct an adaptive deformation model, based on a set of predefined functions and the hypothesis testing theory in the framework of the small baseline subset InSAR (SBAS-InSAR) method. Since it is difficult to fit the deformation time series over a long time span by using only one function, the phase time series is first divided into several groups with overlapping regions. In each group, the hypothesis testing theory is employed to adaptively select the optimal deformation model from the predefined functions. The parameters of adaptive deformation models and the DEM error can be modeled with the phase time series and solved by a least square method. Simulations and real data experiments in the Pingchuan mining area, Gaunsu Province, China, demonstrate that, compared to the state-of-the-art deformation modeling strategy (e.g., the linear deformation model and the function group deformation model), the proposed method can significantly improve the accuracy of DEM error estimation and can benefit the estimation of deformation time series.

Dual Band Slot Antenna for 3.5 WiMAX and 5.8 WLAN

2014 ◽  
Vol 68 (1) ◽  
Author(s):  
Sahar Chagharvand ◽  
M. R. B. Hamid ◽  
M. R. Kamarudin ◽  
Mohsen Khalily
Keyword(s):  
Radiation Pattern ◽  
Coplanar Waveguide ◽  
Single Layer ◽  
Dual Band ◽  
Slot Antenna ◽  
Impedance Bandwidth ◽  
Antenna Gain ◽  
Dual Bandwidth ◽  
Electromagnetic Performance ◽  
Good Agreement

This paper presents a single layer planar slot antenna for dual band operation. The antenna is fed by a coplanar waveguide (CPW) with two inverted C-shaped resonators to achieve the dual band operation. The impedance bandwidth for ǀS11ǀ < -10dB is 14% in lower band and 7% in higher band. The antenna prototype’s electromagnetic performance, impedance bandwidth, radiation pattern, and antenna gain were measured. The proposed configuration offers a relatively compact, easy to fabricate and dual band performance providing gain between 2 and 4 dBi. The designed antenna has good dual bandwidth covering 3.5 WiMAX and 5.8 WLAN tasks. Experimental and numerical results also showed good agreement after comparison.

Optimisation method on conformal array element positions for low sidelobe pattern synthesis

2012 ◽  
Vol 6 (6) ◽  
pp. 646 ◽  
Author(s):  
K. Yang ◽  
Z. Zhao ◽  
J. Ouyang ◽  
Z. Nie ◽  
Q.H. Liu
Keyword(s):  
Array Element ◽  
Pattern Synthesis ◽  
Conformal Array ◽  
Low Sidelobe
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