In this paper, the effects of antenna pattern and antenna polarization on indoor obstructed (OBS) wireless channels are investigated experimentally. Our results show that linearly polarized (LP) directional antennas are more effective in combating multipath components than other types of antennas in OBS channels, The measurement results are verified with a deterministic wide-band propagation mo...

In this paper, a four-element microstrip antenna array is presented. The array is composed of Wilkinson power dividers which act as feed network along with Dolph-Chebyshev distribution and fouridentical patch antenna elements. The array elements are properly designed to have a compact size and constant gain against frequency. The simulated results show good agreement with the measured results f...

In which r is the distance between the antenna and object (meters) and c is the speed of light (3 × 108 meters/sec). Such a system can measure the distance between the antenna and a selected object by the delay T in (1), and the position of that object is determined by antenna poniting. Because the antenna must be switched from Here is a comprehensive review of the current types of microwave se...

Accurate quantification of coarse roots without disturbance represents a gap in our understanding of belowground ecology. Ground penetrating radar (GPR) has shown significant promise for coarse root detection and measurement, however root orientation relative to scanning transect direction, the difficulty identifying dead root mass, and the effects of root shadowing are all key factors affectin...

Jute textile is made from natural fibres and is known for its strength and durability. To determine if jute could be used as a substrate for microstrip antennas, its electromagnetic characteristics (permittivity and loss tangent) are measured in the band of 1 GHz to 5 GHz. The obtained data are used to compare the performances of a simple rectangular patch antenna resonating at 2.45 GHz on jute...

In this paper, two new line-fed loaded planar antennas are proposed for ultra-wideband applications. The first antenna is a circular patch with a circular ring as a Defected Ground Structure (DGS). A 50 Ohm microstrip line passes through the antenna which is symmetrical between the feed and the load. The impedance bandwidth of the first antenna with S11 < −10 dB is more than 10 GHz, from 3 GHz ...

In this paper, internal low-volume antenna structures for mobile terminals are studied. The work concentrates on the possibilities to reduce the volume of mobile terminal antenna elements by efficiently utilizing the radiation of the currents on the mobile terminal chassis. Essentially nonresonant coupling elements are used to optimally couple to the dominating characteristic wavemodes of the c...

The target of the paper is to provide guidelines for indoor antenna selection for passive distributed antenna system or radiating cable implementation. Distributed antenna systems are commonly used for indoor installations, and radiating cables are often used in tunnels, airplanes, or similar constricted areas. However, guidelines for optimizing WCDMA indoor network antenna configuration are la...

In this paper a design of triple band one turn helical antenna without ground plain for center frequency of 2.4 GHz, 3.6 GHz, and 5.4 GHz is discuss. These frequencies are selected such that the antenna radiate for continuous band of 2 GHz to 6.8 GHz frequency with variable gain. The purpose of this novel design is to enhance the gain as well as bandwidth. The triple band is achieved by three c...

Modern spaceborne radar scatterometers such as the NASA Scatterometer (NSCAT) and SeaWinds radar instruments require precise determination of the normalized backscattered radar cross section within a few tenth of a decibel in order to achieve the desired wind velocity and direction measurement accuracy of 2 m/s and 20 degrees respectively. This high level of precision requires a priori prelaunc...