نتایج جستجو برای: array antenna
تعداد نتایج: 171972 فیلتر نتایج به سال:
Reflector antenna optimization schemes using array feeds have been used to recover antenna losses resulting from antenna distortions and aberrations and to generate contour coverage patterns. IIistorically these optimization have been carried out using the antenna far-field scattered patterns. The far-field patterns must be calculated separately for each of the array feed elements. For large or...
An optimal design of a linear antenna array is presented. The antenna array is optimized under the restriction of uniform excitation distribution using a particle swarm optimization based method. The optimization procedure is applied under the requirements for the minimum possible side lobe level and the maximum possible power gain at the desired direction. The method has been applied to collin...
Three working modes, omni-, sector and adaptive modes, for a compact array antenna are introduced. The compact array antenna is an electronically steerable parasitic array radiator (Espar) antenna, which has only a single-port output, and carries out signal combination in space by electromagnetic mutual coupling among array elements. These features of the antenna significantly reduce its cost, ...
A practical normal-mode helical antenna array together with a new method for the compensation of mutual coupling effect is proposed for the efficient adaptive nulling of interferences in a mobile communication environment. The helical antenna array is shown to be able to generate deeper nulls than an equivalent monopole antenna array in the presence of mutual coupling effect. The helical antenn...
A compact size, multiband 2x2 array of circular microstrip antenna has been proposed. The antenna array consists of Genetic Algorithm (GA)optimized, annular slotted circular microstrip antenna elements using probe feed. The spacing of elements has also been optimized using GA in the two directions. The performance of the antenna array has been studied with different shape parameters. The optimi...
In this research, a sub-array preconditioner is applied to improve the convergence of conjugate gradient (CG) iterative solver in the fast multipole method and fast Fourier transform (FMM-FFT) implementation on a large-scale finite periodic array antenna with arbitrary geometry elements. The performance of the sub-array preconditioner is compared with the near-group preconditioner in the array ...
In multi-user beamforming systems, the inter-user interference are controlled by spatial filtering. Since the implementation of digital beamforming is difficult due to high hardware cost of large array system, the analog beamforming system with one phase shifter at each antenna element is considered with antenna selection scheme. However, the beamwidth is not sufficiently narrow to perfectly re...
Microstrip antenna arrays are one of the popular antenna configurations for nowadays wireless communication system. The paper proposes a compact novel design of multiple elements electromagnetically coupled stacked antenna array which operates in Cband. The antenna resonates at 6 GHz and shows bandwidth of 521 MHz with 5.84dBi gain. The proposed antenna shows the ECC to be 0.03 which indicated ...
In the recent years, the optimization techniques using evolutionary algorithms have been widely used to solve electromagnetic problems. These algorithms use thinning the antenna arrays with the aim of reducing the complexity and thus achieving the optimal solution and decreasing the side lobe level. To obtain the optimal solution, thinning is performed by removing some elements in an array thro...
Satellite Communication Systems are beneficial in providing communication services to vast regions especially where the adequate infrastructure for communication may not be constructed. Wireless communication is one of the fastest growing fields in the engineering world. Introduction on adaptive antenna array is described in this paper. Linear adaptive algorithm LMS (Least mean square) is used ...
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