In phased array antennas, the number of radiator rows is one of the important factors to minimizing both cost and weight. Therefore, the antenna tilt angles having relation with the element spacing are among the important design parameters. In this paper, the optimum tilt angles for several types of dipole planar arrays are investigated theoretically. To obtain optimum tilt angles, the directiv...

SOORA, SHRUTHI. A Comparison of Two and Three Dimensional Wire Antennas for Biomedical Applications. (Under the direction of Prof. Gianluca Lazzi.) Miniature antennas are necessary to reduce the size of communications and biomedical devices, specifically for a retinal prosthesis. A comparison of two dimensional and three dimensional antennas are presented as an attempt to miniaturize and reduce...

In recent years, evolutionary optimization (EO) techniques have attracted considerable attention in the design of electromagnetic systems of increasing complexity. This paper presents a comparison between two optimization algorithms for the synthesis of uniform linear and planar antennas arrays, the first one is an adaptive particle swarm optimization (APSO) where the inertia weight and acceler...

The utility and attractiveness of microstrip antennas has made it ever more important to find ways to precisely determine the radiation patterns of these antennas. Taking benefit of the added processing power of today’s computers, electromagnetic simulators are emerging to perform both planar and 3D analysis of high-frequency structures. One such tool studied was IE3D, which is a program that u...

Various smart antennas developed for automatic radio frequency identification (RFID) readers are presented. The main smart antennas types of RFID readers are switched beam, phased array, adaptive beamfsorming and multiple input multiple output (MIMO) antennas. New development in the millimeter wave frequency band60 GHz and above exploits micro-electromechanical system (MEMS) devices and nano-...

Two directional UWB monopole antennas are proposed. It is shown that a design methodology for omnidirectional UWB rectangular planar monopole antennas can be applied for directional ones. The directional features are taken by introducing a slanting angle between the radiator and the ground plane. The slanting angle also plays a role in the low cutoff frequency, and it is considered in a propose...

A planar dual-band semicircle shaped antenna for multiinput multi-output (MIMO) systems is introduced. The antenna was studied experimentally regarding bandwidth and radiation patterns. The measured −10 dB return loss bandwidth is from 2.27 to 2.53 GHz and 5.03 to 5.58 GHz, covering all the 2.4/5.2 GHz WLAN bands. Details of the antenna design, simulated and measured results on the return loss ...

The influence of semi-planar chiral metamaterial (CMM) structures on the important characteristics of circularly polarized (CP) antennas is investigated in this paper. Based on this idea, CP planar two-arm Archimedean spiral (ARSPL) antenna and helical antenna are designed and the effects of chiral covers on their gain (or directivity), axial-ratio (AR), and return loss are considered. The resu...