الفهرس 
Chapter1: IntroductionOnly 14 pages are availabe for public view
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Abstract
This thesis introduces three designs of Ultra-Wide-Band Multi-Input-Multi-Output (UWB MIMO) antennas.
First, a proposed design with compact size (14mm×21mm) planar UWB antenna is proposed. For improving the impedance band width of that antenna to cover the UWB range, truncation on the lower edge of the patch, slots in the ground plane and partial ground plane are used. This antenna is used for designing compact size 4×4 UWB-MIMO antennas. The proposed MIMO structure consists of four identical monopole elements that are placed perpendicular to each other to achieve the pattern diversity among them. It has a compact size of area 42×42 mm2 and operates through a frequency range from 3.2 GHz to 12 GHz which is suitable for UWB applications. To achieve high isolation, stubs between the four radiating elements were used.
Second, to prevent the interference between the UWB applications and the narrowband wireless applications that share the same frequency band, the proposed antenna has been modified to notch out the frequency bands of the WLAN and WiMAX. Two compact UWB MIMO antennas with band notches are proposed. The first proposed design is UWB MIMO antenna with single band notch. It has high isolation (>18 dB) and low mutual coupling with compact size of 42×42×1.6 mm3. It provides band notch characteristics to eliminate the interference with WiMAX applications from 3 GHz to 4 GHz. This band notch of the antenna is accomplished by inserting T strip in the radiating patch. To improve the isolation and the diversity between the radiators, the antennas radiators are arranged on orthogonal form as well as adding decoupling structure between them. The second design proposed compact, four elements with high-performance UWB-MIMO antenna with dual band-notched characteristics. The isolation between the antenna elements was enhanced by assorting the elements of the antenna in an orthogonal manner and applying four stubs interconnecting the elements of the antenna. The proposed antenna achieves two band-notched characteristics by introducing a T-shaped strip etched in the radiating elements and adding an open-loop resonator near the feeding line. The proposed design achieved a wideband from 2.6 GHz to 12 GHz with two band-notched characteristics within 3-4 GHz and within 5.2 GHz - 5.8 GHz. Also, the proposed antenna has high isolation > 20 dB and low-envelope correlation coefficient < 0.005 through the band except for the band notches. All proposed antennas have been simulated, fabricated, and experimentally tested while a good agreement between the simulation and measurements has been obtained.