| Summary: | Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) are well
known equipments used to generate images to aid in diagnostic procedure. However,
the imaging equipments have some limitations whereby the equipments are very
expensive and therefore, they are not always accessible in many medical centres.
Besides, the equipments are bulky and less mobility. Moreover, existing CT cannot be
used frequently on the human body because the scanner exposes patients to more
radiations of ionised frequency. The limitations of the equipment create a need to
design an alternative imaging method which is relatively low cost, small in size, has
high mobility, and non-ionise frequency. This research is to design an antenna for
microwave imaging, namely corrugated u-slot antenna at 1.17-5.13 GHz with the
reference of S11 less than -10 dB. Two corrugated u-slot antennas; namely antenna 1
and antenna 2 are placed on a mirror side of skull phantom to examine their ability to
detect an object inside the skull. VeroClear-RGD810 skull phantom containing water is
used, and the obtained results are verified using ZCorp zp-150 skull phantom which has
approximately similar permittivity. Both the antennas are tested to detect the object
which is located at 40 mm and 80 mm from the respective examined antenna. An
Inverse Fast Fourier Transform (IFFT) technique is used to analyse the time domain
reflection pulse according to the dielectric properties difference, as the electromagnetic
wave propagates through the skull. The results show that the antenna 1 is able to detect
the object faster than the antenna 2 for both skulls, due to inconsistent thickness of the
phantoms. Furthermore, the antennas are fabricated in adjacent to measure
decomposition and superposition specific absorption rate (SAR) in Specific
Anthropomorphic Mannequin (SAM) head phantom at 1800 MHz and 2600 MHz. The
maximum allowable SAR in head is 2 W/kg at 10 g contiguous tissue which is referred
to International Commission on Non-Ionizing Radiation Protection (ICNIRP)
guideline. Based on the measured results, superposition SAR of the antenna can reach
up to ±12% of the maximum decomposition SAR. This research forms a significant
contribution to medical engineering field in designing a corrugated u-slot antenna that
serves to detect an abnormality inside human head at 1.17-5.13 GHz. The designed
antenna satisfies the SAR standard, which is required in microwave imaging
applications.
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