A mathe matical formulation is devised for a uniformly spaced and uniformly progressively phased antenna array of a given number of isotropic ele ments such that the final radiation pattern is end fire with no large bac klobe. The pallern also has the maximum number of sidelobes of equal level, modifying the result of an earlier paper, eve n when the ele ment spacing is made arbitrarily small. ...

Metamaterial and photonic crystal structures are central to modern optics and are typically created from multiple elementary repeating cells. We demonstrate how one replaces such structures asymptotically by a continuum, and therefore by a set of equations, that captures the behaviour of potentially high-frequency waves propagating through a periodic medium. The high-frequency homogenization th...

In wireless sensor network nodes position estimation in space is known as localization. Node localization in wireless sensor network is important for many applications and to find the position with Received Signal Strength Indicator requires a number of anchor nodes. However the estimation of distance from signal strength decay in not very accurate especially in time varying environmental condi...

An artificial neural network (ANN) and affinity propagation (AP) algorithm based user categorization technique is presented. The proposed algorithm is designed for closed access femtocell network. ANN is used for user classification process and AP algorithm is used to optimize the ANN training process. AP selects the best possible training samples for faster ANN training cycle. The users are di...

Artificially designed acoustic meta-surfaces have the ability to manipulate sound energy to an extraordinary extent. Here, we report on a new type of directional reflective surface consisting of an array of sub-wavelength Helmholtz resonators with varying internal coiled path lengths, which induce a reflection phase gradient along a planar acoustic meta-surface. The acoustically reshaped reflec...

In this paper, a novel CPW-fed antenna is presented for UWB applications. The antenna mainly comprises of a simple circular patch and a modified ground plane. The inclusion of two novel symmetrical rectangular slots with inner area of 3×2.8 mm2 to the top corners of the antenna creates a new path for the current and consequently leads to the bandwidth enhancement. A rectangular stub is also ado...

In this study, a radiation pattern reconfigurable microstrip antenna is designed and fabricated. The antenna’s radiation pattern is directed in 9 different angles by employing a radiating patch and embedding complementary split ring resonators (CSRR) on the ground plane. The radiating patch is of circular shape, while for CSRR elements both circular and rectangular shapes are investigated. The ...

background: monte carlo simulations play a vital role in the calculation of the necessary shielding both for neutrons and photons. advanced and simple shielding materials against neutron and gamma rays were compared by simulation using the mcnb4b monte carlo code. the simulations were carried out for the three common neutron sources, namely the 252cf, the 241am/be and the dd neutron generator w...

Microstrip antennas are widely used in a broad range of military and commercial applications due to its low cost, low profile, easy fabrication and light weight. But this kind of antenna also has some drawbacks. For example, the diffraction of surface waves at the edge of finite grounded substrate decreases the antenna efficiency and degrades the antenna pattern [1]. In the phased array antenna...

In this paper, the design and implementation of plasma antenna array with beam forming is discussed. The structure consists of a circular array of plasma tube enclosed in a unipolar UHF band monopole antenna. Beam forming is possible by stimulated plasma tubes. The combination of the above antenna with plasma excitation controller makes a beam forming smart antenna. An experimental model in UHF...