The Development of Ultra Wideband Pulse Radar for Biomedical Application

Abstract

Breast cancer is the recent type in women and incidences are rising in the evolving world because of extended life expectancy, rising urbanization, and expansion of Western lifestyles. Moreover, presently used clinical diagnostic methods, such as X-ray, ultra-sound and MRI, are limited by cost and accuracy case. These limitations have motivated researchers to develop a more effective, low-value diagnostic method and including lower ionization for cancer detection. In this thesis, radar based microwave imaging is suggested as a style in breast cancer imaging system.

Ultra-wideband (UWB) communications is one of the newest technologies employed in imaging systems that are utilized for human’s body imaging. The motivation is mainly based on using ultra-narrow pulses in the time domain to detect and contrast between normal and malignant tissues. The frequency range between 1 and 10 GHz is the optimum band for this application. This band showed high spatial resolution especially at higher frequencies and good penetration depth mainly at lower frequencies. Pulse generator circuit is an important part in UWB systems; it represents the reference to define the other parts of the system. In this way, the circuit of the UWB pulse generator is the main obstacle in the transmitter, which must provide an adequate signal level for the requirements of the proposed application. It must have a minimum of energy consumption and cost.

Firstly, impulse radio UWB is proposed here in designing UWB pulse generator. Two pulse generators are designed dependent on glitch circuit. The first pulse generator is based on delay gate of Output Split Inverter (OSI).The OSI depends on an inverter with current limiting transistor which controls the biasing voltage digitally. The biasing circuit includes current mirror, PMOS transistor which enables 96.5ps delay values. A glitch circuit is designed for a monocycle pulse width of 193 ps thought for breast cancer detection application. The second pulse generator employs transmission gate as an edge combiner in glitch generator to achieve features like a low area, low power consumption, low ringing level. A glitch circuit is designed for a monocycle pulse width 235ps.

Secondly, a typical Ultra wideband Antipodal Vivaldi antenna (APVA) is proposed, which is a class of tapered slot antenna. The antenna