Dawit, Assefa (PhD)Eyob, Adugnaw2021-04-292023-11-042021-04-292023-11-042021-03http://etd.aau.edu.et/handle/123456789/26256Ultrasound is a pressure wave with frequency beyond20 ������ . Wideband ultrasound is ultrasound pulse with mega range of frequency components. Most of the currently available ultrasound transducers are narrow banded and fail to provide better axially resolved images for tissues with multiple layers. The methodology used in this thesis models multi-layered biological medium based on linear acoustics of pulse-echo detection principle, normal incidence, longitudinal ultrasonic propagation and investigates the feasibility to detect periodicity. Ultrasound propagation data was generated synthetically and subjected to cepstral analysis to detect periodicity in a multilayered skin tissue model. Rectangular pulses with a center frequency of 16-30 MHz and pulse duration of 1.2 × 10−7s and 0.8 × 10−7s were applied to a 4-layered medium. The output is measured and cepstral analysis was applied to determine the feasibility of periodicity detection. For layers separated by equal thicknesses, the cepstral peaks existed at equal intervals where as in the case of different layer thicknesses, peaks existed at integer multiple of the thinnest layer thickness. In cepstral analysis, when the cepstral peaks exist at equal intervals or integer multiples of the shortest time of flight (time of flight to the thinnest layer), periodicity detection is guaranteed. It is concluded that periodicity is detected with wideband ultrasound pulses and the minimum and maximum bandwidth are determined based on the duration of the pulse. The possible limitations with the thesis are the assumption of normal incidence planar waveforms, linear ultrasound propagation, and parallel surfaces.en-USCepstrumWidebandPulseUltrasoundLayerPeriodicityThesis