الفهرس 
Microstrip Patch Antenna DesignOnly 14 pages are availabe for public view
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Abstract
In recent year communication systems had been taken more interest in
wireless systems due to easy use and availability everywhere any time.
Front end is considered the main part of wireless equipment, antenna play
the main roles in front end. Microstrip patch antennas have many
advantages make it one of research interest point in last decades.
This thesis concentrates on major parts for enhancing the performance
of microstrip patch antennas (MPAs). In the first part finite difference time
domain method (FDTD) is used to analyze and study the operation of the
microstrip patch antenna. 3D simulation for Maxwell’s equations is carried
here with Liao’s absorbing boundary conditions for the problem space. The
FDTD method is used to calculate the scattering parameters of the patch
antenna and visualize the EM waves through the patch. The calculated
scattering parameters from the FDTD equations are compared with the simulated results. Good agreement between the calculated and simulated
results is achieved In the second part of this thesis, the mutual coupling effects between the
elements of classical microstrip patch antenna arrays (MPAAs) has a great
interest and can affect the performance of MPA. A compact meander
shaped defected ground structure (DGS) is applied to reduce the mutual
coupling (MC) between elements of microstrip antenna array with 0.5 0
elements spacing. The proposed antenna array consists of two elements.
Four meander shaped slots in the ground plane are used between elements
to reduce the coupling between the array elements. The antenna is simulated
using CST microwave studio software, fabricated on FR4 substrate with
dielectric constant of 4.3 and thickness of 1.6 mm by etching the groundplane of the microstrip antenna and measured. The results show that a
reduction in mutual coupling from -23 dB to -52 dB is obtained between
elements at the operating frequency of the antenna array. The gain is
increased by 0.6 dBi. A small shift in operating frequency from 4.74 to 4.8
GHz is introduced. The measurement results prove the high efficiency of
this configuration.The last part in this thesis has two topics the first topic is the dual band
microstrip patch antenna (DBMPA) design on FR4 substrate with dielectric
constant of 4.3 and thickness of 1.6 mm by etching the patch using loaded
C-shape slot with three stubs, the patch has 2.4 GHz and 3.5 GHz resonance
frequency. The second topic is designing isolated elements DBMPAA with
small mutual coupling using C-shape DGS, the MC reduction has been
achieved for the low frequency because of the high frequency has low MC
without the DGS. The results show that a reduction in mutual coupling from
-25 dB to -47 dB is obtained between elements at the low operation
frequency of the antenna array. Good agreement between the FDTD
calculated and simulated results is achieved. The proposed DBMPAA
loaded with C-shape DGS fabricated and measured. Good agreement between the simulated and measured results is achieved.