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Hamid Reza Hassani

Bio: Hamid Reza Hassani is an academic researcher from Shahed University. The author has contributed to research in topics: Microstrip antenna & Monopole antenna. The author has an hindex of 25, co-authored 85 publications receiving 1902 citations. Previous affiliations of Hamid Reza Hassani include K.N.Toosi University of Technology & University of Essex.


Papers
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Journal ArticleDOI
TL;DR: In this article, a small-size microstrip-fed multi-band planar monopole antenna is presented, which covers the frequency bands 1.3, 1.8, 2.4 and 3.6 GHz.
Abstract: A small-size microstrip-fed multi-band planar monopole antenna is presented. The base of the proposed antenna is a diamond-shaped-patch (DSP) that covers the ultrawideband (UWB) frequency range. To create a multi-band antenna, several narrow strips, acting as resonance paths, can be integrated with the DSP antenna. It is shown that by removing the centre part of the DSP antenna, without distorting the UWB behavior, quarter-wavelength strips can be added to the notched region. This will not affect the dimension of the base antenna. The designed quad-band antenna has a substrate size of 16 × 22 mm2 and covers the frequency bands 1.3, 1.8, 2.4 and 3.1-10.6 GHz which includes GPS, GSM, WLAN and UWB. Dual-, triple- and quad-band antennas are simulated and good results are obtained. The antennas have omnidirectional and stable radiation patterns across all the relevant bands. Moreover, relatively consistent group delays across the UWB frequencies are noticed for the base, dual- and triple-band antennas, and slightly distorted for the quad-band antenna. A prototype of the quad-band antenna is fabricated and measured results are compared with simulated results.

162 citations

Journal ArticleDOI
TL;DR: In this article, a low-profile antenna consisting of an octagonal-shaped slot fed by a beveled and stepped rectangular patch for covering the UWB band (3.1-10.6 GHz) was presented.
Abstract: A novel compact ultrawideband (UWB) printed slot antenna with three extra bands for various wireless applications is presented. The low-profile antenna consists of an octagonal-shaped slot fed by a beveled and stepped rectangular patch for covering the UWB band (3.1-10.6 GHz). By attaching three inverted U-shaped strips at the upper part of the slot in the ground, additional triple linear polarized bands can be realized covering GPS (1520-1590 MHz), part of GSM (1770-1840 MHz), and Bluetooth (2385-2490 MHz). Simulated and measured results are presented and compared, which shows that the antenna has a stable radiation pattern both at the triple and the whole of the UWB bands.

136 citations

Journal ArticleDOI
TL;DR: In this article, a multiband E-shaped printed monopole antenna for multiple-input-multiple-output (MIMO) system is presented, which can create a single resonance within the WLAN range.
Abstract: A novel multiband E-shaped printed monopole antenna for multiple-input-multiple-output (MIMO) system is presented. The proposed E-shaped monopole antenna can create a single resonance within the WLAN range. Placement of two slots within the E-shaped monopole antenna creates two extra resonances whose center frequencies can be adjusted by the E-shaped monopole and the slots parameters. The antenna parameters for WLAN application, covering 2.4, 5.4, and 5.8 GHz, are given. Various configurations of array of this E-shaped monopole antenna for MIMO application are also studied. It is shown that good MIMO performance can be achieved even for small element spacing. Simulation and measurement results are compared and discussed.

121 citations

Journal ArticleDOI
TL;DR: In this paper, a unit cell consisting of two thin dielectric layers placed on top of each other, with annular ring slots placed on the outer layers and a PBG element placed on a common interface is presented.
Abstract: A novel ultrathin slot-based transmitarray antenna is presented The related unit cell consists of two thin dielectric layers placed on top of each other, with annular ring slots placed on the outer layers and a PBG element placed on the common interface The combination of the two annular ring slots and the PBG element acts as a bandpass filter for the transmitted wave The design of the elements can be carried out through a simple circuit-based analysis approach The proposed two-layer structure, the unit cell, has a thickness of $0033\lambda_{\rm o}$ and provides the required 360 $^{\circ}$ of phase shift Furthermore, over the bandwidth, the unit cell can have up to 7 $^{\circ}$ of phase error for incident angles of up to 50 $^{\circ}$ The unit cell and the full transmitarray prototype are fabricated, and the results were compared with simulation and discussed The full transmitarray has $-$ 1 dB gain bandwidth of 57% and efficiency of 38% at the center frequency The structure is simulated via HFSS and CST software package

117 citations

Journal ArticleDOI
TL;DR: Abbaspour et al. as discussed by the authors proposed a new wideband and small size star shaped patch antennafed capacitively by a small diamond shape patch to enhance the impedance bandwidth, posts are incorporated under the patch antenna.
Abstract: WIDEBANDSTAR-SHAPEDMICROSTRIPPATCHANTENNAM.AbbaspourandH.R.HassaniElectrical Engineering DepartmentShahed UniversityTehran, IranAbstract—A new wideband and small size star shaped patch antennafed capacitively by a small diamond shape patch is proposed.Toenhance the impedance bandwidth, posts are incorporated under thepatch antenna.HFSS high frequency simulator is employed to analyzethe proposed antenna and simulated results on the return loss, the E-and H-plane radiation patterns and Gain of the proposed antenna arepresented at various frequencies.The antenna is able to achieve in therange of 4–8.8GHz an impedance bandwidth of 81% for return loss ofless than

106 citations


Cited by
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01 Jan 2016
TL;DR: This rfid handbook fundamentals and applications in contactless smart cards and identification helps people to read a good book with a cup of coffee in the afternoon instead of juggled with some malicious bugs inside their laptop.
Abstract: Thank you for reading rfid handbook fundamentals and applications in contactless smart cards and identification. As you may know, people have search numerous times for their chosen novels like this rfid handbook fundamentals and applications in contactless smart cards and identification, but end up in malicious downloads. Rather than reading a good book with a cup of coffee in the afternoon, instead they juggled with some malicious bugs inside their laptop.

570 citations

Journal ArticleDOI
TL;DR: In this paper, a critical overview of possible solutions for dual-frequency patch antennas is presented, and future perspectives are outlined, in particular geometric and spectral properties of patch antennas are discussed.
Abstract: Dual-frequency patch antennas may provide an alternative to large-bandwidth planar antennas, in applications in which large bandwidth is really needed for operating at two separate transmit-receive bands. When the two operating frequencies are far apart, a dual-frequency patch structure can be conceived to avoid the use of separate antennas. In this paper, a critical overview of possible solutions for dual-frequency patch antennas is presented, and future perspectives are outlined. Geometries are discussed in particular.

467 citations

Journal ArticleDOI
TL;DR: In this article, a compact multiple-input-multiple-output (MIMO) antenna for ultrawideband (UWB) applications is presented, which consists of two open L-shaped slot (LS) antenna elements and a narrow slot on the ground plane.
Abstract: A compact multiple-input-multiple-output (MIMO) antenna is presented for ultrawideband (UWB) applications. The antenna consists of two open L-shaped slot (LS) antenna elements and a narrow slot on the ground plane. The antenna elements are placed perpendicularly to each other to obtain high isolation, and the narrow slot is added to reduce the mutual coupling of antenna elements in the low frequency band (3-4.5 GHz). The proposed MIMO antenna has a compact size of 32 ×32 mm 2 , and the antenna prototype is fabricated and measured. The measured results show that the proposed antenna design achieves an impedance bandwidth of larger than 3.1-10.6 GHz, low mutual coupling of less than 15 dB, and a low envelope correlation coefficient of better than 0.02 across the frequency band, which are suitable for portable UWB applications.

280 citations

Journal Article
TL;DR: Cooperative spectrum sensing in cognitive radio(CR) networks is analyzed and detection probability to primary users can be improved by multi-cooperative users in multi-user networks.
Abstract: Cognitive users need to detect primary users continuously and rapidly.Cooperative spectrum sensing in cognitive radio(CR) networks is analyzed.Cooperative spectrum sensing in the ideal network with two cognitive users can reduce the mean detection time.Detection probability to primary users can be improved by multi-cooperative users in multi-user networks.Finally,the realization of multi-user networks is considered.

267 citations

Journal ArticleDOI
TL;DR: In this paper, the design of a four-band slot antenna for the global positioning system (GPS), worldwide interoperability for microwave access (WiMAX), and wireless area network (WLAN) is presented.
Abstract: The design of a four-band slot antenna for the global positioning system (GPS), worldwide interoperability for microwave access (WiMAX), and wireless area network (WLAN) is presented. The antenna consists of a rectangular slot with an area of ${\mathbf{0}}.{\mathbf{37}}{\lambda _g} \times {\mathbf{0}}.{\mathbf{14}}{\lambda _g} = {\mathbf{48}} \times {\mathbf{18}}\;{\bf m}{{\bf m}^{\mathbf{2}}}$ (where ${\lambda _g}$ is the guide wavelength), a $T$ -shaped feed patch, an inverted $T$ -shaped stub, and two $E$ -shaped stubs to generate four frequency bands. The radiating portion and total size of the antenna are less than those of the tri-band antennas studied in literature. Parametric study on the parameters for setting the four frequency bands is presented and hence the methodology of using the design for other frequency bands is proposed. The multiband slot antenna is studied and designed using computer simulation. For verification of simulation results, the antenna is fabricated and measured. The simulated and measured return losses, radiation patterns, realized peak gains, and efficiencies of the antenna are presented. Measured results show that the antenna can be designed to cover the frequency bands from 1.575 to 1.665 GHz for the GPS system, 2.4–2.545 GHz for the IEEE 802.11b&g WLAN systems, 3.27–3.97 GHz for the WiMAX system, and 5.17–5.93 GHz for the IEEE 802.11a WLAN system. The effects of the feeding cable used in measurement and of the cover are also investigated.

224 citations