Advanced Electromagnetics (E-Journal)
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299 research outputs found
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A Compact Broad-band UHF RFID Tag Loaded with Triangular SRR Arrays
No full textA novel compact planar UHF RFID tag with broadband operation and enhanced read range characteristics are presented. The structure of the tag consists of a T- matched dipole antenna whose arms are orthogonally loaded with Triangular SRR arrays. Triangular SRR arms loaded in the structure produce compactness and good impedance matching which is needed for maximizing the read range. The measured results shows that the projected tag shows a highest read range of 9.6 meter in the European UHF RFID band of 866 MHz and significantly better read range in the other UHF RFID bands in the 860-930 MHz range . Measured read range differences over the azimuth and elevation angular ranges are also suggested
Design of Compact Broadband Omni directional Canonical Sleeve Antenna covering 500-3600 MHz
No full textA novel compact broadband Canonical Sleeve Antenna (CSA) covering 500-3600 MHz with omni directional characteristics is presented in this paper. A new method is employed in which the radiating antenna structure is designed as combination of three different canonical structures: hemispherical, conical and cylindrical elements. To accomplish the broad bandwidth with compact size, dipole antenna is designed by using cylindrical sleeve over the hemispherical dipole with conical extensions and cylindrical attachments. Performance characteristics of CSA is simulated and compared with BiConical Antenna (BCA) and other antenna configurations and found to be best antenna configuration with compact form factor. The antenna has height of 111.43 mm and diameter of 116.66 mm. Simulation studies are carried out using CST Microwave Studio. The simulated results are validated by fabricating CSA and evaluating its performance metrics. CSA has 7.2:1 bandwidth with measured VSWR <2.7:1 and Gain varies from 0 to 3.6 dBi. The antenna finds use in wireless communication industry, spectrum monitoring and defence applications
Statistical Moments and Scintillation Level of Scattered Electromagnetic Waves in the Magnetized plasma
No full textStatistical characteristics of scattered ordinary and extraordinary electromagnetic waves in the magnetized plasma are considered using the smooth perturbation method. Diffraction effects and polarization coefficients are taken into account. Second order statistical moments of scattered radiation are obtained for arbitrary correlation function of electron density fluctuations. Broadening of the spatial power spectrum and displacement of its maximum, wave phase structure function and the angle-of-arrivals are obtained for three-dimensional spectral function containing anisotropic Gaussian and power-law spectral functions. Scintillation level of scattered radiation is analyzed for different parameters characterizing anisotropic plasma irregularities for the ionospheric F-region. The spectral widths (first and second moments) of the power spectrum and scintillation periods are calculated for “frozen-in” drifting elongated plasma irregularities using the experimental data
Design of a Compact Dual-Band Microstrip Antenna Enabled by Complementary Split Ring Resonators for X-Band Applications
No full textIn this paper, a design of highly effective dual-band microstrip antenna for X-band applications is developed. Dual-band response is obtained by etching four rectangular split ring resonator (RSRR) unit cells within the radiating element of a conventional patch initially designed to operate at 10 GHz. The proposed antenna is constructed on low lossy RT/duroid 5880 (ϵr = 2.2, tan δ = 0.0009) substrate of 20x20x1.575 mm3 total area. The antenna is tuned to operate at two resonant frequencies within 8 to 12 GHz depending on the geometric specifications of the RSRR's. A parametric study of different numbers of unit cells etched on the radiating element is investigated and discussed comprehensively through this study. Realized gain of about 6.2 and 6.8 dB at 8.8 and 10 GHz are attained. Consistent results are obtained between the measurements and simulation results using 3D full-wave FEM-base simulator
A Dual-Band Printed Slot Antenna for WiMAX and Metrological Wireless Applications
No full textNew microstrip antenna initiated from the portions of 1st order structures of Sierpinski square geometry is modeled in this paper as quasi-fractal device using an FR4 substrate of 4.4 dielectric constant, 1.6 mm thickness and 0.02 loss tangent. The intended microstrip antenna is designed for band frequencies of 3.5 and 7.8 GHz for WiMAX and metrological satellite applications with a bandwidth of 0.66 and 0.78 GHz for each band respectively. The designed antenna has considerable compact size that is smaller than many reported fractal and non-fractal antenna structures in the literature. Also, it has interesting return loss and radiation results that can be employed in diverse wireless devices. Measured input reflection coefficient, radiation patterns and gain results have been found in good agreement with those predicted by simulations
Polarization Reconfigurable Square Patch Antenna for Wireless Communications
No full textIn this paper, a single fed polarization reconfigurable antenna is proposed. The antenna consists of a radiating patch incorporated with a diagonal-shaped slot at its center. Four p-i-n diodes are used for polarization reconfiguration. The p-i-n diodes are placed in diagonal slot region. The proposed antenna is designed to operate in three states – linear polarization (LP), left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP) by biasing corresponding p-i-n diodes. The antenna gives measured peak gain of 6.2 dBi for LP state and 5.82 dBic for both RHCP and LHCP states. It also achieves 3-dB axial ratio bandwidth of 5.95% for both RHCP and LHCP configurations. The antenna finds application in areas of modern wireless communication
Compact Broadband Monopole Antenna for C Band Applications
No full textThis paper reports a new design of broadband monopole patch antenna. The proposed antenna possess corner truncated rectangular patch with slits and defected ground structure, these modifications considerably improves the impedance bandwidth to 41.29% over a wideband (5.1–7.59 GHz). The design is appropriate for wireless communication including WLAN IEEE 802.11 g/a (5.15–5.35 GHz and 5.725–5.825 GHz) and C Band (4–8 GHz) applications. An antenna prototype is fabricated using FR-4 with an electrical permittivity of 4.4. Experimental and numerical simulations of antenna’s radiation characteristic are also reported and exhibits good concurrence
Compact Size Triple Notched-bands UWB Antenna with Sharp Band-Rejection Characteristics at WiMAX and WLAN Bands
No full textIn this paper, a compact triple band-notched Ultra Wideband (UWB) antenna with sharp band-elimination features and controlled notched bandwidths is proposed and discussed. The design is made up of a rectangular-shaped patch UWB planar monopole antenna with double collections of band-notched configurations. The band-notched configurations are involved to produce the desired lower and upper stop bands with good frequency selectivity and suitable stop bandwidths. The first notch is realized by using a C-shaped slot etched in the radiating patch in order to eliminate the interference at the WiMAX (3.4 - 3.8 GHz) applications. The second and the third notches are realized together by using a pair of U-shaped resonators that are located beside the feed line in both sides to eliminate the interference with the lower WLAN (5.15–5.35 GHz) and the higher WLAN (5.725–5.825GHz) bands. Additionally, the bandwidths of the lower and upper stop bands can be control separately by changing the parameters of the band-notched configurations. Furthermore, the suggested triple notched bands UWB antenna is optimized, fabricated, and measured for verification purposes. The measured results are close to the simulated ones
New Compact Wideband Microstrip Antenna for Wireless Applications
No full textIn this paper, a miniature rectangular microstrip antenna over partial ground plane is presented by utilizing a space-filling property of fractal geometry in this design. It is simulated by High Frequency Software Simulator (HFSS) software, fabricated and tested by Vector Network Analyzer (VNA).Two types of slots are introduced in order to enhance antenna parameters such as bandwidth and return loss S1.1. This antenna is fabricated on FR4 substrate with a small size of (18 x 16 x 1.5) mm3, 1.5mm substrate thickness, 4.3 permittivity and 0.02 loss tangent. To feed this antenna, microstrip line feed is used. This antenna is implemented for wide bandwidth (4.8-11.6) GHz, and has three resonant frequencies at 5.5GHz, 8.3GHz and 10.7GHz with impedance bandwidth of 6.8GHz. The gap value g between partial ground plane and rectangular patch at top layer is optimized in order to achieve optimal simulated return loss S1.1 is (-46,-32,-14) dB at three resonant frequencies (5.5, 8.3, 10.7) GHz and optimal radiation efficiency of 93.42% with gain of 3.63dB. The simulated results have tolerable agreement with measured results. This antenna is suitable for wireless computer applications within C and X band communications
Optimized 3-D electromagnetic models of composite materials in microwave frequency range: application to EMC characterization of complex media by statistical means
No full textThe aim of this proposal is to demonstrate the ability of tridimensional (3-D) electromagnetic modeling tool for the characterization of composite materials in microwave frequency band range. Indeed, an automated procedure is proposed to generate random materials, proceed to 3-D simulations, and compute shielding effectiveness (SE) statistics with finite integration technique. In this context, 3-D electromagnetic models rely on random locations of conductive inclusions; results are compared with classical electromagnetic mixing theory (EMT) approaches (e.g. Maxwell-Garnett formalism), and dynamic homogenization model (DHM). The article aims to demonstrate the interest of the proposed approach in various domains such as propagation and electromagnetic compatibility (EMC)