In this paper, we propose a new compact quasi-fractal shaped microstrip antenna that consists of a hexagonal patch as the main radiator and a complementary stacked patch as the parasitic element. The overall surface of the proposed quasi-fractal patch is about 55% lower than the conventional hexagonal patch. Using of stacked technique, the gain reduction of compression technique is almost compe...

nowadays, environment-sensitive smart drug delivery systems have found diverse applications in pharmaceutical science and technology. these systems can respond to the environment stimuli such as temperature, pressure, ph, light, electrical and magnetical fields and etc. they can release the proper amount of drug in human body. among these systems, special attention and much research works have ...

Recently, researchers were interested in neural algorithms for optimization problems for several communication systems. This paper shows a novel algorithm based on neural technique presented to enhance the performance analysis of beam-forming in smart antenna technology using N elements for Uniform Circular Array (UCA) and Concentric Circular Array (CCA) geometries. To demonstrate the effective...

In this paper, we propose a dual smart antenna system incorporated into handsets for the 3GPP WCDMA system, in which a diversity combiner combines the two rake receiver outputs using a diversity combining scheme. We considered three diversity combining schemes, selection diversity, square law combining, and equal gain combining (EGC), and two types of the channel model for the dual antenna sign...

We present measurement results with a GSM1800 smart antenna base station. The base station is equipped with an adaptive antenna array processor that allows in every GSM frame full beam adaptation in uplink and downlink. The smart antenna processing is based on the estimation of the directions of arrival in uplink. It includes separate DOA trackers for uplink and downlink, angular diversity, and...

The smart antenna is a technology and has been applied to the cellular and mobile communication system. It is a combination of multiple antenna elements with a signal processing capability to optimize its radiation and/or reception pattern automatically change in response to the signal environment. The core of smart antenna is the selection of smart algorithms in adaptive array. In this paper, ...

The term smart antenna incorporates all situations in which a system is using an antenna array and the antenna pattern is dynamically adjusted by the system required.Two major issues in smart antennas are Direciton of Arrival (DOA) estimation and beamforming. The Direction of Arrival of all the incoming signals including the interfering signals are estimated using DOA algorithms.Some of the DOA...

This chapter introduces the concept of multi-beam antenna (MBA) in mobile ad hoc networks and the recent advances in the research relevant to this topic. MBAs have been proposed to achieve concurrent communications with multiple neighboring nodes while they inherit the advantages of directional antennas, such as the high directivity and antenna gain. MBAs can be implemented in the forms of mult...

We present the performance gain of dual smart antennas with an adaptive combining at handsets for the 3GPP WCDMA system. The adaptive algorithm based on the normalized least-mean-square (N-LMS) algorithm is employed, in which antenna weights are recursively obtained. To obtain the channel profile, we adopted the GBSB (geometrically based single bounce) elliptical and circular models. The simula...

Smart adaptive antenna technology is considered to be the last technology frontier that has the potential of leading to large increases in systems performance. Time domain techniques have been extensively exploited. Space domain techniques, on the other hand, have not been exploited to the same extent. When applied to wireless, the benefits of smart adaptive array a antennas are as follows: (i)...