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Reconfigurable microstrip antennas w...

Khidre, Ahmed.

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Reconfigurable microstrip antennas with tunable radiation pattern characteristics.

紀錄類型:	書目-電子資源 : Monograph/item
正題名/作者:	Reconfigurable microstrip antennas with tunable radiation pattern characteristics./
作者:	Khidre, Ahmed.
面頁冊數:	145 p.
附註:	Source: Dissertation Abstracts International, Volume: 75-11(E), Section: B.
Contained By:	Dissertation Abstracts International75-11B(E).
標題:	Electromagnetics. -
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3628562
ISBN:	9781321046472

Reconfigurable microstrip antennas with tunable radiation pattern characteristics.
Khidre, Ahmed.

Reconfigurable microstrip antennas with tunable radiation pattern characteristics. - 145 p.

Source: Dissertation Abstracts International, Volume: 75-11(E), Section: B.

Thesis (Ph.D.)--The University of Mississippi, 2014.

This item is not available from ProQuest Dissertations & Theses.

Reconfigurable beam antenna systems are capable of changing their radiation characteristics in real time, such as beam direction, beam shape, beamwidth, etc. Such antenna system is desired for various wireless applications because of many reasons among them; it helps to enhance signal strength received from an intended target, mitigates interference, and accommodates sudden changes in traffic demand of wireless networks. It might also help to reduce the deployment cost of wireless networks infrastructures.

ISBN: 9781321046472Subjects--Topical Terms:

3173223
Electromagnetics.

Reconfigurable microstrip antennas with tunable radiation pattern characteristics.
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020 $a 9781321046472
035 $a (MiAaPQ)AAI3628562
035 $a AAI3628562
040 $a MiAaPQ $c MiAaPQ
100 1 $a Khidre, Ahmed. $3 3175293
245 1 0 $a Reconfigurable microstrip antennas with tunable radiation pattern characteristics.
300 $a 145 p.
500 $a Source: Dissertation Abstracts International, Volume: 75-11(E), Section: B.
500 $a Advisers: Fan Yang; Atef Z. Elsherbeni.
502 $a Thesis (Ph.D.)--The University of Mississippi, 2014.
506 $a This item is not available from ProQuest Dissertations & Theses.
506 $a This item must not be sold to any third party vendors.
506 $a This item must not be added to any third party search indexes.
520 $a Reconfigurable beam antenna systems are capable of changing their radiation characteristics in real time, such as beam direction, beam shape, beamwidth, etc. Such antenna system is desired for various wireless applications because of many reasons among them; it helps to enhance signal strength received from an intended target, mitigates interference, and accommodates sudden changes in traffic demand of wireless networks. It might also help to reduce the deployment cost of wireless networks infrastructures.
520 $a In this dissertation, designs for reconfigurable beam microstrip antennas with tunable radiation characteristics have been proposed. The method to achieve these designs is the reconfigurable parasitic element (s) of tunable electrical size, placed in close proximity to the driven patch. A tuning mechanism with the aid of Varactor diodes is introduced for the parasitic patch that effectively allows for controlling its electrical size. This (these) reconfigurable parasitic patch (es) is (are) then applied in different fashions to devise several antenna designs with dynamic electronic control over certain radiation specifications. The accomplished antenna designs in the dissertation are:
520 $a • Circularly polarized (CP) beam scanning antenna, where two elements microstrip Yagi-Uda antenna is used. The first element is a square patch driven with two probe feeds of quadrature phase for CP excitation. The second element is a parasitic square patch with narrow square-shaped slot carved on its surface. The parasitic patch is adjacent to the driven patch with a small separation distance. Four varactor diodes are placed on the middle of each side of the square slot to facilitate tuning of its electrical size. The parasitic patch electrical size is allowed to be effectively tuned by varying the applied reverse biasing DC voltage to the varactors (capacitance value). The CP beam direction is scanned from -36° to 32° with gain variation from 5.7 to 8.2 dBic, and efficiency from 54% to 75.58% along the scanning range.
520 $a • Two-dimensional beam scanning antenna, where two orthogonal crossed Yagi-Uda antenna configuration is utilized. The driven element is a square patch excited with a probe coaxial feed. The other two parasitic patches are closely placed along the E & H planes of the driven patch. Each parasitic patch has a narrow rectangular slit at its center, where a varactor diode is placed to allow for tuning its electrical size. The beam direction is permitted to be scanned in both the elevation and azimuth planes. The achieved scan range in the elevation plane is from 0° to 32°, whereas in azimuth plan is from 0° to 90°. Along the scanning range, the attained gain changes from 8.1 to 8.9 dBi, and efficiency changes from 86% to 93%.
520 $a • Tunable beamwidth antenna, with a dynamic control over the radiation beam focusing is proposed. The antenna consists of a square patch excited by a coaxial probe feed, and other two square parasitic patches placed on both sides of the driven along its H-plane. Each parasitic patch has a narrow slit at its center loaded with lumped varactor diode to tune its electrical size. Upon changing the parasitic patches size, the antenna effective aperture is altered, and hence the beamwidth in the H-plane is controlled. The achieved beamwidth tuning range is from 52° to 108°, whereas the gain changes from 6.5 to 8.1 dBi.
520 $a Throughout the dissertation, 2.45 GHz is chosen, as an example, to be the target frequency. All the designs are validated through experimental measurements for fabricated prototypes, and good agreement is observed between the predicted and measured results.
590 $a School code: 0131.
650 4 $a Electromagnetics. $3 3173223
650 4 $a Electrical engineering. $3 649834
650 4 $a Engineering. $3 586835
690 $a 0607
690 $a 0544
690 $a 0537
710 2 $a The University of Mississippi. $b Electrical Engineering. $3 1679376
773 0 $t Dissertation Abstracts International $g 75-11B(E).
790 $a 0131
791 $a Ph.D.
792 $a 2014
793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3628562