in some mobile systems, intelligent antennas are used to increase efficiency in a wide frequency band and different environmental and electromagnetic conditions. environmental factors, such as position of nearby objects, antenna mobility and even user type, can vary the antenna input impedance appreciably. therefore, it is necessary to incorporate an adaptive impedance matching circuit between ...

This paper proposes a novel pre-FFT type OFDM adaptive array antenna called “Eigenvector Combining.” The eigenvector combining array antenna is a realization of a post-FFT type OFDM adaptive array antenna through a pre-FFT signal processing, so it can achieve excellent performance with less computational complexity and shorter training symbols. Numerical results demonstrate that the proposed ei...

A new four elements compact antenna array is presented and discussed to achieve enhanced phase resolution without sacrificing the array output power. This structure inspired by the Ormia Ochracea’s coupled ears. The analogy between this insect acute directional hearing capabilities and the electrically compact antenna array is used to enhance the array sensitivity to direction of arrival estima...

-This paper discusses the deployment of Genetic algorithm optimization method for synthesis of antenna array radiation pattern in adaptive beam forming. The synthesis problem discussed is to find the weights of the antenna array elements that are optimum to provide the radiation pattern with maximum reduction in the side lobe level. This technique proved its effectiveness in improving the perfo...

Channel capacities and data rates of mobile communications have been increasing to meet demands of modern communications. In order to achieve a low bit error rate (BER), we need high signal to interference plus noise ratio (SINR). To realize the high SINR, it is effective to use an adaptive array antenna [1]. The adaptive array antenna can reduce the influence of multipath rays. On the other ha...

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, ...