Abstract:
Due to inherent noise like characteristics, Ultra wideband (UWB) radio signals are highly suitable for less invasive medical applications. So, apart from the short distance high-speed communication, nowadays Ultra wideband systems are considered a viable alternative for microwave imaging because of its penetration capability and high precision imaging. In this thesis work, an IR-based UWB transmitter and front end receiver are proposed for medical imaging and short distance data communication. The transmitter generates Gaussian monocycle pulse with only data as its input, thus relaxing the complexity of any synchronization. A new modulation technique is incorporate to facilitate this transmitter for both imaging and data communication within FCC unlicensed band (3.1-10.6GHz with EIRP <-41.3dBm/MHz) with a flexibility of varying data speed from few MHz to 4GHz with low power operation. Simulation has shown the proposed design consumes 0.68pJ/bit irrespective of data speed. The proposed source degenerated CS-CG cascode low noise amplifier cascaded with Chebyshev filter shows better noise performance, forward gain and input matching and lower power consumption. A buffer stage is employed to increase the forward gain of the circuit. The -3dB bandwidth of the LNA is 6.2GHz from 4.7-10.9GHz with flat response of 12.1±.3dB from 5.2-9.8GHz. The input and output reflection co-efficient are below -10dB within the band of interest. The simulated average noise figure is below 3.2dB. The core amplifier consumes 5.22mW power and all the transistors are biased within the circuit. The proposed circuits are designed using IBM 130nm CMOS RF technology and simulated in Cadence Spectre and Hspice RF.
