الفهرس 
Chapter 1: IntroductionOnly 14 pages are availabe for public view
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Abstract
In this thesis two microstrip patch, linear antennas arrays are designed and analyzed using
CST and HFSS simulators. The goal of this thesis is to detect cancer tumors, especially in the brain
and kidneys. Brain tumor detection was by simulating the reflection coefficient of the antenna
which was put on the top of a head model with and without tumor. The difference in S11 was
enough to detect small tumors even their radii were 2.5mm. The first patch antenna array used an
EBG in the ground plane. Two types of EBG are proposed. The first type is a rectangular lattice
of holes which produced an increase in S11 by 19% at the same resonance frequency which is 3.9
GHz with and without tumor. The second one is a squared lattice of holes that presented an increase
of 27 % in S11. It also provides a 2.9% shift in the resonant frequency at -10 dB on a head phantom
with a brain tumor compared to without a tumor. The electric field, magnetic field, and current
density are calculated in each type of EBG.
A remarkable difference has been observed between with and without tumors especially
on the squared lattice. One-, two and four- elements linear antenna arrays are designed to be put
at a 10-mm distance from the head phantom. The purpose of antenna arrays is to provide sufficient
energy to penetrate human tissues. The directivity was 6.65 dB, 8.5 dB, and 12 dB in one element,
two elements, and four elements respectively. The S11 is calculated for each antenna on a head
phantom with and without a tumor. The S11 values are increased by 1.05dB, 2.73dB, and 4dB for
the three cases respectively. Also, the E and H fields, current density, and specific absorption rate
SAR are calculated.
In addition, the second antenna array was also used for brain tumor detection. The
antenna used was a reconfigurable four-element linear array of squared microstrip patches. Two
arrays were designed one circularly polarized, the other linearly polarized. The antenna operates
at Industrial
Scientific and Medical (ISM) frequency 2.4 GHz. It was designed on FR-4 (lossy) substrate of
relative permittivity 4.3 and thickness of 1.6 mm. To feed the array, a corporate feeding network
was designed. The reconfigurability of the array was achieved using three single pole double throw
(SPDT) switches. Two models of the human head were used; a specific anthropomorphic
mannequin (SAM) model, and a 3-D head model consisting of four different head layers: skin, fat,III
skull and brain. The simulation calculates the reflection coefficient (S11) with and without tumor
for circularly polarized (CP) and linearly polarized (LP) linear array. Calculations were taken for
four sizes of the array. The best results were obtained with the four-element circularly polarized
array. An increase in S11 of 1188% was obtained. Tumors as small as 5 millimeters (four-layer
model) and 2.5 mm (SAM model) can be detected. Specific absorption rate (SAR) was calculated
and found to be within the safe limit. A circularly polarized four-element linear antenna array was
fabricated. The measured S11 and radiation pattern are in excellent agreement with simulated ones.
Moreover, kidney cancer detection was also one of our goals in this thesis. The previous
CP and LP linear antenna arrays were also used to detect kidney tumor stages. Renal cancer tumors
are divided into four phases where the increase in reflection coefficient and the shift in resonance
frequency are calculated for each stage. At 2.4 GHz, the S11 for the four stages of cancer are 5,
6.9, 14.1, and 16.6 dB, respectively. For the four stages, there is also a shift in resonance frequency
of 2, 3, 18, and 28 MHz, respectively. In its advanced stages 3 and 4, the tumor is simple to detect.
LP antenna was simulated and calculated ∆S11, and the shift in frequency at 2.3 GHz. The increase
in S11 of CP than LP was 455.6%, 155.6 %, 261.5 %, and 186.2 % form stage 1 to stage 4
respectively.
The shift in resonance frequency for the early stages is too small. Therefore, detection depends
mainly on the increase in S11. The shift in resonance frequency and increase in S11 are large for
advanced stages of the tumor, which makes detection easier. Computed specific absorption rate
(SAR) is found to be less than the safety levels.