| Recently, ultra wideband (UWB) technology has received considerable attention from both the academia and industry. It found applications in wireless personal area network (WPAN) due to high data throughput capability, low power requirements and short-range characteristics. In addition to wireless communications, other interesting applications are in the area of position detection and imaging such as the ground penetrating radar (GPS) system. These types of single radio applications do not necessarily require standards to be successful.; This dissertation addresses the design and implementation issues of the analog front-end for the CMOS UWB receiver. Although increasing bandwidth is desired from system perspective, it however demands more stringent higher dynamic range requirements from implementation point of view. As the dynamic range is limited by the noise, the design objective in this dissertation is to develop low noise design techniques for two important building blocks: low noise amplifier (LNA) and mixer.; LNA plays an important role in the analog front-end receiver. The goal in the design of LNA is to achieve sufficient gain and low noise so as to suppress the noise from the following stages. This dissertation proposes a new design methodology for LNA with source-degeneration topology for wideband systems. It is demonstrated that the proposed wideband LNA can achieve the minimum achievable NF at all frequencies of interest while satisfying the maximum power transfer condition.; The major problem in the mixer is the leakage of flicker noise which has the detrimental effect on the desired signal after downconverted to the baseband. To effectively reduce the flicker noise, this dissertation describes a new flicker noise reduction technique which requires the mixer to operate at OFF overlap mode. To better understand the noise behavior, we propose the first analytical model for the LPTV system which is used to model the mixer. Our analysis shows that the mixer with OFF overlap mode yields a better tradeoff among the design parameters, e.g., conversion gain, noise figure and power dissipation. |
