الفهرس 
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Abstract
In recent years, wireless communication systems have advanced rapidly. This raises the need to have wide bandwidth antennas for multiple wireless applications. Therefore, the design of broadband microstrip antennas has become very vital for multiband applications. The major goal of this thesis is to design and analyze two microstrip antennas, namely: the mirror stairs antenna and parasitic hat antenna based on defected structures (DGS and DMS). The first part of this work is the mirror stairs microstrip antenna consisting of five rectangular slots etched into the ground plane below the microstrip line. Three rectangular strips form a patch on the front side of the antenna. The proposed mirror stairs antenna is simulated by HFSS electromagnetic simulator using the finite element method (FEM). The mirror stairs antenna is manufactured on a RO4350B substrate material with a double-sided board with dimensions of 45 mm x 40 mm x 1.524 mm. The suggested antenna’s measurement and simulation results are compared. The second part of this thesis introduces a parasitic microstrip hat antenna design based on defected structure for multiband applications. The antenna design is made up of five rectangular slots with defects in the ground structure, each has the same width but a different length. To create a parasitic hat antenna based on defected microstrip structure (DMS), a rectangular patch of dimensions 30 mm×11 mm is cut with four L-shaped slots that are connected with a rectangular slot in the middle of the front side of the antenna. Simulation and experimental results show a good agreement with return loss S11 ≤ -10 dB at seven operating frequencies that extends in the range of 2 to 17 GHz.