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...

The rapidly increasing demand for PCS has provided the impetus to design adaptive antenna arrays to improve spectral efficiency and enhance system capacity. With increasing data rate in some PCS application like DECT( Digital European Cordless Telecommunications), higher BER would degrade the system performance further. An adaptive antenna array testbed using 12 elements was built to evaluate i...

The current wireless cellular base station antenna system employs switched beam technology which suffers from its inefficiency to track the user and limited capacity. The Smart antenna technology which tracks the mobile user continuously by steering the main beam towards the user and at the same time forming nulls in the directions of the interfering signal. The development of smart antennas in...

Side lobe and directivity of antenna array is main problem in radar and communication field. This paper describes linear antenna array radiation pattern in adaptive beam forming using genetic algorithm. Unlike Simple GA (SGA), Genetic Algorithm is an iterative stochastic optimizer that works on the population values based on the fitness value. This improves the performance of the maximum reduct...

Adaptive antenna arrays are widely used in wireless communication and radar. The understanding of array design and optimization often needs sophisticated signal processing methods to estimate the Degree of Arrival (DoA). DoA estimation algorithms often require numerical analysis. We propose an educational tool that can be utilized for adaptive antenna array simulation and DoA estimation. There ...

In a time division duplex (TDD) based adaptive array antenna (AAA)/space division multiple access (SDMA) system, the array weights determined from up-link signals can be applied to the down-link transmission because of the channel reciprocity. However, under fast fading conditions, for example due to fast moving mobile station (MS), the array weights are no longer optimum for the down-link sign...

Antenna array is the most important aspect to improve the communication process. The objective of this paper are to minimize the maximum side lobe level (SLL) and perform null steering for linear antenna arrays by controlling different parameters of the array elements (phase, position and amplitude). The Nature inspired optimization methods like Taguchi’s Optimization Method (TM), Self-Adaptive...

In this paper, an adaptive array antenna is implemented to enhance the performance of digital TV ISDB-T reception. Issues of realizing the proposed array antenna and its implementation by a joint hardware-software solution are also presented in this paper. Instead of using known reference signals, the proposed method utilizes the GI (Guard Interval) and a periodic property of OFDM signal as a c...