Adaptive antenna arrays have recently been introduced to cope with the high capacity required by the 3 generation (3G) wireless communications systems. As adaptive antenna arrays focus narrow high gain beams towards the desired user and nulls towards interferers, both coverage and capacity of the network can be improved. To establish the performance gain that a smart antenna can deliver in a 3G...

Mobile and wireless communication systems have now arrived at the point where substancial advances in antenna technology have become a critical issue. The majority of these systems consist of an antenna array combined with an appropriate signal processing (Soni et al., 2002; Godara, 2002), i.e., the antenna elements are allowed to work in concert by means of array element phasing, which is acco...

In this paper we investigate comparison methods of different geometric configurations of adaptive antenna arrays for mobile communications. The investigated antenna configurations were linear, semicircular, rectangular, wing and zigzag array. All considered antenna arrays consisted of seven antenna elements with an inter-element spacing of half wavelength. The Geometry macrocellular environment...

Abstract Complex and dynamic control of radiated fields are advantageous for flexible radio systems, which naturally move, roll, bend, twist, deform, vibrate. Practical challenges hinder the proliferation these antenna arrays. This work shows how using radio-frequency microchips reduces system component count, decreases mass to ~0.1 g cm −2 , increases functionality mechanical flexibility. We d...

In this paper, a vector channel model is proposed and some statistical properties of the asymptotic efficiency of the decorrelating detector with base-station antenna arrays are investigated. It is shown that we can get gain over the conventional decorrelator by employing antenna arrays and the gain increases as the number of antennas increases and the angle dispersion decreases. It is also sho...

.............................................................................................. 3 1 Theoretical Background ..................................................................... 5 1.1 What is an Active Phased Array Antenna? ............................................................... 5 1.1.1 Switched Beam Antenna ....................................................................

Optimizing antenna arrays to approximate desired far field radiation patterns is of exceptional interest in smart antenna technology. This paper shows how to apply artificial intelligence, in the form of neural networks, to achieve specific beam-forming with linear antenna arrays. Multilayer feed-forward neural networks are used to maximize multiple main beams’ radiation of a linear antenna arr...

Abstract— This work investigates the improvement of the active reflection coefficient of waveguide-fed phased-array antenna using liquid crystal layers. The anisotropy properties of liquid crystal layer can be employed to eliminate blind scan angle and improve the wide angle impedance matching of the waveguide-fed phased array antennas. The authors have expressed the modal analysis of the waveg...

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...