Antenna Theory And Design

IEEE Antennas and Wireless Propagation Letters

A novel broadband dual-polarization antenna utilizing strong mutual coupling with high isolation is presented in this communication. The antenna is composed of two orthogonally situated dipoles which have square-loop shape arms (SLSAs). And to shape the radiation pattern of the antenna, a metal reflector is placed under the antenna. By elaborately utilizing the strong mutual coupling between the two dipoles, very good impedance match and sufficiently high isolation can be achieved simultaneously, the reasons for which are analyzed in this communication. Both the simulated and the measured results show that a more than 57.5% impedance bandwidth with SWR 31 dB can be achieved for the proposed antenna. As an important advantage, the input impedance of the antenna can be controlled within certain limits by adjusting the configurations, thus the antenna can be fed directly by coaxial cables without using impedance transformers. Besides, the antenna structure is compact and simple.

A Novel Broadband Dual-Polarization Antenna Utilizing Strong Mutual Coupling

Crossed dipole antennas have been widely developed for current and future wireless communication systems. They can generate isotropic, omnidirectional, dual-polarized (DP), and circularly polarized (CP) radiation. Moreover, by incorporating a variety of primary radiation elements, they are suitable for single-band, multiband, and wideband operations. This article presents a review of the designs, characteristics, and applications of crossed dipole antennas along with the recent developments of single-feed CP configurations. The considerations of profile miniaturization, radiation pattern control, bandwidth enhancement, and multiband operation are emphasized.

Crossed Dipole Antennas: A review.

Grasshopper Optimization Algorithm (GOA) is a recent swarm intelligence algorithm inspired by the foraging and swarming behavior of grasshoppers in nature. The GOA algorithm has been successfully applied to solve various optimization problems in several domains and demonstrated its merits in the literature. This paper proposes a comprehensive review of GOA based on more than 120 scientific articles published by leading publishers: IEEE, Springer, Elsevier, IET, Hindawi, and others. It provides the GOA variants, including multi-objective and hybrid variants. It also discusses the main applications of GOA in various fields such as scheduling, economic dispatch, feature selection, load frequency control, distributed generation, wind energy system, and other engineering problems. Finally, the paper provides some possible future research directions in this area.

/pdf/grasshopper-optimization-algorithm-theory-variants-and-3nn15nvo6g.pdf

Grasshopper Optimization Algorithm: Theory, Variants, and Applications

In this paper, a new design of a dual-polarized antenna with high isolation and low cross polarization is proposed. The main radiation structures comprise two pairs of petaloid patches, which are fed by coaxial lines. Behind the patches, a U-shaped ground is placed to improve the front-to-back ratio of the antenna. Stable and symmetric radiation patterns at slanted §45 - polarization have been obtained within the frequency band 1.71{2.17GHz. A return loss of i14dB is achieved and measured isolation between the two input ports is over 31dB. The 3dB beamwidths of the two polarizations is stable (65 - ) and the average gain of the proposed antenna is about 9dBi across the whole frequency band.

/pdf/a-novel-dual-polarized-antenna-with-high-isolation-and-low-5a6csfragm.pdf

A Novel Dual-Polarized Antenna with High Isolation and Low Cross Polarization for Wireless Communication

Comprehensive structural analysis and optimization of the electrostatic forming membrane reflector deployable antenna

A novel compact wideband patch antenna is presented. The antenna consists of two simple patch pairs with opposite phase feed. Considering the coupling between two patches in the design, an antenna with a size about 54.5 × 22 × 20 mm3 is constructed and tested. The simulated and measured results show that the antenna has the active reflection coefficient less than -9.6 dB in the band 2.6-6 GHz. The radiation performance of the antenna is good over the whole frequency band.

Compact Broadband Crescent Moon-Shape Patch-Pair Antenna

Antenna arrays with high directivity, low side-lobe level, and null control in desired direction and whip antenna with wider bandwidth both need to be optimized to meet different needs of communication systems. A new natural heuristic algorithm simulating social behavior of grasshoppers, grasshopper optimization algorithm (GOA), is applied to electromagnetic field as a new effective technology to solve the antenna optimization problem for the first time. Its algorithm is simple and has no gradient mechanism, can effectively avoid falling into local optimum, and is suitable for single-objective and multiobjective optimization problems. GOA is used to optimize the side lobe suppression, null depth, and notch control of arbitrary linear array and then used to optimize the loading and matching network of 10-meter HF broadband whip antenna compared with other algorithms. The results show that GOA has more advantages in side-lobe suppression, null depth, and notch control of linear array than other algorithms and has better broadband optimization performance for HF whip antenna. The pattern synthesis and antenna broadband optimization based on GOA provide a new and effective method for antenna performance optimization.

/pdf/optimal-pattern-synthesis-of-linear-array-and-broadband-4c9c85u70u.pdf

Optimal Pattern Synthesis of Linear Array and Broadband Design of Whip Antenna Using Grasshopper Optimization Algorithm

This study presents a novel optimization algorithm based on invasive weed optimization (IWO) for reduction of the maximum side lobe level (SLL) with specific half power beam width (HPBW) of thinned large multiple concentric circular arrays of uniformly excited isotropic elements. IWO is a powerful optimization technique for many continuous problems. But, for discrete problems, it does not work well. In this paper, the authors propose an improved binary IWO (IBIWO) for pattern synthesis of thinned circular array. The thinning percentage of the array is kept equal to or more than 50% and the HPBW is attempted to be equal to or less than that of a fully populated, uniformly excited, and half wavelength spaced concentric circular array of the same number of elements and rings. Simulation results are compared with previous published results of DE, MPSO, and BBO to verify the effectiveness of the proposed method for concentric circular arrays.

/pdf/thinning-of-concentric-circular-antenna-arrays-using-2heyy6csez.pdf

Chao Liu

Papers

A Novel Dual-Polarized Antenna with High Isolation and Low Cross Polarization for Wireless Communication

Comprehensive structural analysis and optimization of the electrostatic forming membrane reflector deployable antenna

Compact Broadband Crescent Moon-Shape Patch-Pair Antenna

Optimal Pattern Synthesis of Linear Array and Broadband Design of Whip Antenna Using Grasshopper Optimization Algorithm

Thinning of Concentric Circular Antenna Arrays Using Improved Binary Invasive Weed Optimization Algorithm