For hostile communication environments, noncentralized mobile communication network with directive/adaptive antennas and Global Positioning System (GPS) has been proposed for the purpose of minimizing the radio exposure and making it difficult for an interceptor to detect the signals. This paper investigates the interceptor’s search for the direction-of-arrival (DOA) of the transmitting signal ...

Introduction: Short-circuited microstrip patch antennas, or PIFAs, can be used as directive internal handset antennas in various communication systems. They provide advantages over traditional external whip and helix antennas in terms of increased total efficiency (when the handset is near the user’s head), decreased radiation towards the user, and increased mechanical reliability. The main dis...

In this paper, the conformal finite-difference time-domain (CFDTD) method using PSO optimization is applied to design a compact directive balanced antipodal Vivaldi antenna for ultrawideband (UWB) applications. This paper demonstrates miniaturized antipodal Vivaldi antenna (32 × 35 × 1.6mm3), having low-cross polarization levels and reasonable gain from 3.1 to 10.6 GHz. The antenna peak gain is...

There is a huge increase in design of various wireless antennas for daily and commercial use. They are designed with various specifications. After deeply analyzing the comparisons, this paper is a result of comparison of two designs, namely micro strip patch antenna at 2.4GHZ using EZNEC and another micro strip patch antenna at 10.65GHZ using ADS. This comparison differentiates the results base...

Design of thinned elliptical antenna arrays of uniformly excited isotropic antennas using particle swarm optimization (PSO), is reported. Thinned arrays can generate directive beam with minimum side lobe level (SLL) without degrading the performance of fully populated antenna arrays significantly. Thinning of elliptical antenna arrays using PSO are optimized with different values of eccentricit...

This paper presents some considerations on the design, characterization and optimization of UWB (Ultra WideBand) antennas for consumer communication equipment. As a first step a method to extract the spatio-temporal UWB antenna characterization from a FDTD simulation is given. Thereafter, the shape of a planar monopole is optimized to provide broadband matching. This is followed by the integrat...

A low profile dual-band multiple-input-multiple-output (MIMO) antenna system is proposed. The proposed MIMO antenna consists of two low profile unbalanced fed inverted L antennas with parasitic elements to resonate at 2.45 GHz and 5 GHz. The structure is uncomplicated by locating two ultra low profile inverted L antennas on the finite conducting plane. The proposed MIMO antenna is numerically a...

Design of thinned semi-elliptical and quarter-elliptical antenna arrays, with uniform excitation and uniform spacing using genetic algorithm (GA) optimization, is presented in this paper. Thinned arrays produce narrow directive beam without causing major degradation of fully populated antenna arrays. Semi-elliptical array contains antenna elements along half of the elliptical geometry and quart...

We investigate the performance and coexistence techniques for worldwide interoperability for microwave access (WiMAX) delivered from high altitude platforms (HAPs) and terrestrial systems in shared 3.5 GHz frequency bands. The paper shows that it is possible to provide WiMAX services from individual HAP systems. The coexistence performance is evaluated by appropriate choice of parameters, which...

The integration of metamaterial superstrate with high-quality cavity 3-poles stacked filter with patch antenna is presented. The metamaterial inspired behavior is obtained using split ring resonators (SRR) printed on the dielectric substrate Rogers 5880 which is located 12 mm from the top of the filter/antenna. The effects of the metamaterial structure on the vertically stacked filter/antenna p...