• List of Articles آنتن

      • Open Access Article

        1 - Design, simulation and performance comparison of radating elements of reflect array antenna
        iman aryanian gholamreza moradi abdolali abdipour
        In this paper, the role of radiation elements in the performance of reflect array antenna is studied, and each element is designed and simulated and the phase response is compared. Also, the relations needed for designing reflect array antenna are discussed and one samp More
        In this paper, the role of radiation elements in the performance of reflect array antenna is studied, and each element is designed and simulated and the phase response is compared. Also, the relations needed for designing reflect array antenna are discussed and one sample reflect array antenna is designed in the KU band and the results are presented. Manuscript profile
      • Open Access Article

        2 - Parametric analysis of a broadband Archimedean spiral antenna with cavity
        Hamed  noroozy Shahrokh  jam
        In this article an Archimedean spiral antenna is designed and analyzed that has good operation in broadband application. By analyzing this design, the effects that different parameters have on antenna operation will be studied and ways of optimization will be found.  In More
        In this article an Archimedean spiral antenna is designed and analyzed that has good operation in broadband application. By analyzing this design, the effects that different parameters have on antenna operation will be studied and ways of optimization will be found.  Influences of cavity height and number of turns to obtain good matching and gain in a frequency interval of 4 to 18 GHz will be discussed. In addition, using cavity wall around the antenna, side lobes are decreased or deleted. By tapering the arms at feeding center, better matching will be attained. For making S11 bandwidth better, increasing the cavity height or reducing the number of turns can be used. Changing number of turns does not have a significant effect on the gain. To improve the antenna gain, the cavity height needs to be adjusted such that the reflected wave from cavity and radiated wave from spiral arms are constructing. Manuscript profile
      • Open Access Article

        3 - Improving the directivity of the plasmonic sectoral horn nanoantenna using lens in its aperture
        Masumeh  Sharifi Najmeh  Nozhat Ehsan  Zareian-Jahromi
        Horn antennas can result in good impedance matching between the waveguide and free space due to the gradual increase in the aperture size. In this paper, a novel plasmonic sectoral horn nanoantenna based on using lens in the aperture is proposed. It is investigated that More
        Horn antennas can result in good impedance matching between the waveguide and free space due to the gradual increase in the aperture size. In this paper, a novel plasmonic sectoral horn nanoantenna based on using lens in the aperture is proposed. It is investigated that in addition to improvement of the directivity, the reflection coefficient is also reduced using the proper lens structure. The maximum directivity improvement is about 2 dBi compared to the structure without lens. Also, it is shown that the radiation pattern can be controlled by utilizing electro-optical material as the lens Manuscript profile
      • Open Access Article

        4 - Improvement of the bulk sensitivity and FoM of the plasmonic nanodipole antenna array
        Samira  Amiri Najmeh  Nozhat
        In this paper, the sensitivity of a plasmonic nanodipole antenna array for different materials of the metal nanodipole and substrate is calculated by changing the refractive index of the surrounding medium. The performance of our proposed array is studied at two wavelen More
        In this paper, the sensitivity of a plasmonic nanodipole antenna array for different materials of the metal nanodipole and substrate is calculated by changing the refractive index of the surrounding medium. The performance of our proposed array is studied at two wavelengths of 1310 and 1550 nm, the wavelengths of the second and third telecommunications windows. It is shown that by using the silver (Ag) nanodipole instead of the gold (Au) one, the bulk sensitivity of the nanostructure is improved. By replacing the substrate material from Si to SiO2, the sensitivity increases up to 1220 and 1150 nm/RIU at the wavelengths of 1310 and 1550 nm, respectively, that is very suitable for sensing applications. Moreover, the figure of merit (FoM) of the plasmonic sensor is calculated for both substrates and nanodipole materials. The maximum value of the FoM is obtained for the nanoantenna array with SiO2 substrate and Ag nanodipole and it is equal to 14.35. Furthermore, it is shown that by increasing the thickness of the nanodipole, the nanostructure sensitivity and FoM are enhanced Manuscript profile
      • Open Access Article

        5 - Polar Diagram of Points with Moving Pole
        Bahram Sadeghi Bigham fateme rabani
        Polar diagram is a generalization of Voronoi diagram in which the angle is used as the metric. This Problem has many applications in visibility, image Processing, telecommunication, antenna, and Path Planning Problems. In recent years two kinds of Polar diagram have bee More
        Polar diagram is a generalization of Voronoi diagram in which the angle is used as the metric. This Problem has many applications in visibility, image Processing, telecommunication, antenna, and Path Planning Problems. In recent years two kinds of Polar diagram have been proposed and appropriate algorithm have been Presented for some types of sites. Also, some algorithms has presented for kinetic data and dynamic states. In this Paper, it is assumed that the Pole is moving and an algorithm is presented that updates near Pole Polar diagram of sites with moving pole efficiently and in a sub linear time. In this approach, the Preprocessing time is 〖O(n^4 log〗_2⁡〖n)〗 and updating time for diagram with each successive movement is 〖 O(log〗_2⁡〖n +k)〗 that k is the number of sites in region T which its site’s regions may be changed Manuscript profile