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This paper demonstrates the feasibility of reducingradar cross-section by employing resistive sheets or rings inthe conducting elements of an FSS unit cell. The idea behindthe approach in question is to create power-absorbing elementswhich may help reduce the power reflected from FSS surface.The investigated FSS unit cells have the form of double-closedrings and double-closed-split rings. A carbon...
A split circular element is proposed as a unit cell for reflectarray antennas. The unit cell is derived from a circle divided into four equal sectors. The radius of two oppositely located sectors is then scaled by a certain factor to form the proposed shape. The CST Microwave Studio Suite software simulator was used to investigate the performance of the proposed unit cell, which was evaluated using...
An arc-shaped planar-monopole two antennas for WLAN and WiMAX application is proposed. The lengths of the two arcs are designed to meet the requirements for the WLAN and WiMAX standard sat 2.45GHz and 3.5GHz respectively. The separation between centers of the two feed lines is 14 mm (0.098 wavelengths at 2.45GHz).A new technique is proposed to reduce the mutual coupling between the two closely-spaced...
The favorable features of the long-term evolution (LTE) standard has attracted much interest. At the lower bands of the LTE systems, designers of mobile handsets antennas face challenges of the conflicting requirements of limited space and long wavelengths. A multi-band PIFA antenna that is printed directly on the substrate is proposed for mobile handset applications. A parametric study using the...
The long-term evolution (LTE) standard has attracted much interest because it offers many advantages. Antenna designers for the lower band of the LTE700 band for mobile handsets have to compromise between the limited space in the handset and long wavelengths implied by frequency of operation. An antenna with meandered line-PIFA combination is proposed as a solution for the above challenge. The influences...
The long-term evolution (LTE) standard has attracted much interest due to its many advantages. Antenna design for the lower band of the LTE systems for mobile handsets faces challenges of the limited space and long wavelengths. An LTE smart mobile antenna is presented, and influences of various design parameters are investigated using the CST Microwave Suite. The antenna shape was then modified to...
A double planar monopole antennas for WLAN and WiMAX application is proposed. Each antenna is represented in the form of crescent-shaped monopole structure. The lengths of the two arcs are designed to resonate at 2.45GHz, and 3.5GHz to meet the requirements for the WLAN and WiMAX standards respectively. The two monopoles have a small separation distance of 9mm (i.e., 0.0735λ0 at 2.45GHz). A new technique...
A crescent-shaped planar monopole antenna for UWB applications is proposed. The design parameters were investigated using CST software package. Modeling of the UWB monopole antennas is investigated using two methods. The input impedance is represented by the first Foster canonical form, where the equivalent circuit components at resonance are derived from either the reflection coefficient or the input...
Synthesis of wide beam array antennas is investigated using phase-only excitations for uniform amplitude array. In this approach random phase distribution is proposed. Symmetrical and asymmetrical distributions of the random phase are considered. The obtained patterns are assessed by comparing beam width and maximum level of the radiated field with those obtainable from the conventional broadside...
Printed elliptical monopole antenna PEMA has been designed to cover the UWB frequency range. The design procedure of this antenna is accomplished by two stages; Firstly, the PEMA has been designed according to some suggested and known formulas. Secondly, two impedance matching (IM) techniques are suggested to improve the designed antenna by moving the locus of the input impedance towards the center...
This paper presents design and performance analysis of three proposed shapes for use as microstrip patch elements for reflectarray antenna. The elements are formed of patches of variable size. The comparison focuses on effect of the elements shapes and boundaries on the performance of reflection phase represented by; range, slope and magnitude. Variation of the responses with frequency is also investigated...
This paper presents design and performance analysis of various element shapes for microstrip reflectarray formed of patches of variable size. The comparison focuses on effect of the elements boundaries on the performance represented by the range and slope of the reflection phase response. Variation of the response with frequency is also investigated to assess the frequency response of the proposed...
Fractal concept has been used for broadbanding printed monopole antennas to comply with UWB requirements. The concept of self similarity has been deployed, where repeated square and triangular shapes form the composite monopoles to increase their frequency ranges. In each of the designed antennas, the shape has been scaled up then repeated in vertical direction away from ground plane. The proposed...
The paper presents the design of a linearly polarized single-layer reflectarray which employs a fixed-size circular ring with a variable-length open-circuited stub run around it as a phasing element. To achieve a slow phase slope, a thick foam material is used to support this element developed on a thin substrate. Investigations are performed to achieve a linear reflection phase as function of the...
The design of a microstrip reflectarray formed by 81 variable size double elliptical rings illuminated by a conical feed is presented.Because of double resonance, the double elliptical rings provide an increased phasing range of unit cells that exceeds the required minimum of 360°. Printed on a single substrate and supported by a layer of foam and a conducting ground, they also offer a slow phase...
In phased arrays the mainbeam is scanned by either varying the phase excitations of the elements or varying the frequency of operation. In spite of their extensive use, these methods need either variable phase shifters or frequency sweeping. It is shown here that beam scanning is also feasible by varying magnitudes of the array element excitations thus alleviating the need for phase shifters or frequency...
This contribution treats the simulation of pulse Doppler radar system by using PC and MATLAB Simulink. The simulator has been implemented through hardware represented in the AT computer interface card while the software was build with C++ language. The phase detector unit was built using MATLAB Simulink programs. Various MTI systems were studied and sample results for single canceller and matched...
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