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Cloaking refers to hiding a body from detection by surrounding it with a coating consisting of an unusual anisotropic nonhomogeneous material. The radially-dependent spherical cloaking shell can be approximately discretized into many homogeneous anisotropic layers, provided that the thickness of each layer is much less than the wavelength, and this discretization raises the level of scattering as...
In this paper we introduce, for the first time, a compact and dual band substrate integrated waveguide metamaterial impedance transformer. The proposed transformer has been proposed to functions at bandwidth from 4.5 GHz and 6.5 GHz for all possible upper WiMAX frequencies. The design procedures supported by the analytical model has been explained in details. The design of the proposed transformer...
A new technique to mitigate the inter cell interference for cell edge users in LTE-A system combining soft fractional frequency reuse (SFFR) with adaptive beamforming technique is introduced in this paper. SFFR has some disadvantages such as reducing the spectral efficiency and the frequency selectivity gain. The minimum mean square error (MMSE) adaptive beamforming is considered in the analysis with...
In this paper, a system level design of a 2.45 GHz RFID reader transceiver front-end for the entire 2400–2483.5MHz RFID band supporting ISO 18000-4 standard is presented. Based on the physical layer parameters of the mentioned standard, and given required antenna gain, the transceiver architecture is chosen, designed and optimized for optimum sensitivity, linearity and noise figure using link budget...
In this paper, a new method of investigating the electronic properties of double-walled carbon nanotube is introduced. The method is based on dealing with it as two concentric single-walled carbon nanotubes. The results confirm that double-walled carbon nanotubes can be classified as semi metallic, from the electronic conductivity point of view, regardless the electronic type of the two concentric...
Novel planar ultra-wideband Vivaldi antenna is introduced for water detection using GPR with good performance as compared to conventional TEM horn antenna. An exponential tapered slot edge (TSE) structure with etched six pairs of defected ground structure as electromagnetic band gap (EBG) is employed. The proposed shape has the advantage of extending the low-end bandwidth limit and improves the antenna...
In this paper, two identical rectangular DRAs are used as a unit cell in the reflectarray structure. The proposed reflectarray has broadband characteristics covering the X-band and Ku-band. Full-wave analysis using finite integral technique (FIT), finite element method (FEM) and transmission line method (TLM) are used.
In this paper, we propose a stop-band notch filter, which rejects the narrow frequency band of the Wi-MAX 802.16d (3.4 GHz to 3.6 GHz) and keeps the remaining UWB spectrum (3.1–3.4 and 3.6–3.9 GHz) unchanged. The proposed filter has been realized using the metamaterial technology based on the CRLH metamaterial structures. The selected center operating frequency is 3.5 GHz, which is the mid-band frequency...
This paper proposes a new mobile handset antenna structure with compact size and multibands to reduce the value of the specific absorption rate (SAR). The antenna is based on a monopole and a meander line structure that operates at the dual-bands from (587–977 MHz) and (1.67–8.63 GHz) to cover most of the mobile operating bands and other wireless applications. The covered bands are the GSM 900, DCS...
A compact ultra wide band filter for high speed communication has been introduced. The designed filter is based on a modified configuration of microstrip stepped impedance resonator filter. The detailed design theory and design procedures have been introduced. The design has been validated using both circuit simulation and electromagnetic full wave simulation. Finally, experimental measurements have...
In this paper, reflectarrays mounted on or embedded in cylindrical or spherical surfaces are designed, analyzed, and simulated at 11.5 GHz for satellite applications. The effect of the cylindrical or spherical surfaces curvature with different subtended angles on the radiation characteristics of the designed reflectarrays are investigated and compared with that of planar reflectarray. Full-wave analysis...
In this paper, the radiation characteristics of a cylindrical perforated transmitarray are investigated. Concave and convex cylindrically conformal transmitarrays are designed and analysed using the finite integral technique. Centre and offset beams transmitarrays are considered for satellite applications at 10 GHz. Perforation technique is used to construct the concave and convex transmitarrays from...
Wavelets provide an effective toolbox for solving differential equations by representing the continuous functions by their wavelet expansion coefficients and the corresponding differential equations by discrete matrix equations. The wavelet basis functions are organized into resolution levels of different frequency terms at different locations, and the main advantage of the wavelet expansion representation...
A compact double-ridged horn antenna (DRH) for the transmitter of ground penetrating radar applications in the frequency range of 80MHz to 1GHz. Within this contribution the design and simulation of such an antenna will be considered for water level detection in Egyptian dessert aquifers (depth ≥ 10m). Among the varying horn design parameters, the linear and exponentially tapered walls are studied...
In this paper, a simple method to estimate the relative permittivity εr and the tangential loss tan(δ) of wearable textiles is presented. Quarter-wavelength stub-line band-stop filters, based on jeans and cordura textiles, are designed assuming reasonable initial values of εr and tan(δ), fabricated and experimentally tested. The filter designs are then re-simulated, by tweaking the values ofεr and...
This paper investigates the design of four different configurations of plasma reflectarrays. The results provide insight into different radiation characteristics of plasma reflectarrays. The proposed unit cell consists of cubic glass box filled with Argon gas energized with applied AC voltage. The reflectarray reflection coefficients phase variation is achieved by varying the plasma frequency of the...
This paper presents a modification on the structure of a recently proposed microstrip reflectarray cell, called Phoenix [4]. Phoenix cell was developed to operate in the X-band frequency range for a linearly polarized microstrip reflectarray antenna. Phoenix is designed to overcome the limited antenna bandwidth being a common issue faced by most microstrip reflectarray cells. The design is based on...
Wideband operation and pattern shaping in one dimension can be achieved using a planar array antenna with a real-valued coefficients or weights. The extra dimension is used to sample the signal in space and treat each frequency independently. Two methods to calculate the weights for the desired array pattern have been compared. These are Spatial Response Variation Constraint Pattern Synthesis (SRVCPS)...
A new combination of aperture coupled microstrip antenna and metamaterial cover structure is applied to achieve 10.5 dB gain. We also report an integration of conical frame with aperture coupled microstrip antenna to increase the gain from 5.7 dBi to 12.2 dBi and a bandwidth of 12.2% over 11.05 GHz – 12.5 GHz. The presence of the metamaterial cover and conical frame has improved the back-lobe level...
Circularly polarized dish antennas are of great importance since they have better immunity to external types of noise compared to linearly polarized ones. Dish parabolic antennas with end-fire helical feeds provide circular polarization, high directivity and relatively low level of side lobs, however, the conducting ground plane of the helical feed results in a blockage of the reflected rays from...
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