We have proposed design of ESPAR (Electronically Steerable Parasitic Array Radiator) antenna that is capable of electronic beam steering in order to avoid interference, null is placed in direction of interference source whereas maxima is placed in direction of desired signal source. Paper includes formulation of mathematical model, simulation and later designing of ESPAR antenna capable of dyna...

this paper describes the design of a 2x2 micro strip patch antenna array in the frequency of 9.5ghz for radar applications, using substrate integrated waveguide, siw, for feeding network. the micro strip patches are aperture-coupled with the feeding network of siw. the feeding network consisting of a perpendicular coax-to-siw transition and two y-junction power dividers. the antenna is simulate...

The construction of a low-cost and reliable array antenna system is required to facilitate the practical use of the adaptive antenna in the mobile communication field. The array antenna system can be verified by DOA (Direction of Arrival) estimation. This dissertation describes the attempt to achieve a high-precision adaptive antenna and the examination of this device, which suppresses the numb...

In this paper we analyze the temporal and spatial compression characteristics of retrodirective antenna systems wherein active phase conjugation (APC) is deployed. It is shown that under the active phase conjugation Hermitian channel matrix properties result and these lead to opportunities for both temporal and spatial signal compression. The effects of additive channel noise, as well as compre...

This paper presents an element of a 2×2-element array antenna for Inmarsat BGAN/GPS applications. The element is an axial mode printed quadrifilar helical antenna that has been integrated with a compact feed network to provide sequential phase rotation for circular polarization (CP) radiation. The novel integrated lumped-element feed network is designed to provide a balanced RF power to the fou...

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 ...

Evolutionary Search Algorithms (EA) have been intensively used in solving numerical optimization problems. Since design of antenna arrays is a numerical optimization problem, EAs have been intensively used in solving antenna arrays design problems. Although EAs are widely used in antenna array design problems, a performance comparison study of the intensively used EAs for circular antenna array...

A wireless sensor server is developed based on a reconfigurable active smart-antenna/retrodirective array. The system can serve as both a retrodirective array transponder and a smart-antenna receiver simply by changing the frequency of the local oscillator applied to the mixers, enabling it to best utilize its hardware to suit its communication environment. When operating as a direct-conversion...