Programmable LC resonant circuit and its application in reconfigurable LC QVCO design

Abstract

As the development cycle of the wireless communications technology fastens, the importance of reconfigurable design grows larger and larger. Reconfigurable design enables effective implementation of a multi-standard transceiver which can processes signals from multiple existing wireless standard. In addition, it may possibly be used as a test-bed for next generation transceiver development. With the success of high integration level architectures such as DCR (Direct conversion receiver) and Low-IF receiver, now it is a feasible goal to develop a single path multi-standard transceiver. By adopting an effective reconfigurable design method, a low power high integration level transceiver may be designed. In this dissertation, I proposed programmable LC resonant circuit for reconfigurable design of RF front-end, and applied it to the design of a reconfigurable CMOS LC QVCO. In chapter 2, the concept of programmable LC resonant circuit is introduced. Composed of L array and C array with switches, a programmable LC resonant circuit can achieve optimized characteristics at each frequency of interest, and it can find its application as a matching circuit, a load, or LC tank of a VCO. However, as the MOS switches are not ideal switches but has some parasitic; thus, the characteristics of MOS switches and trade-off in the selection of switch size are analyzed. In chapter 3, the basic operation of differential LC VCO and its phase noise characteristics are reviewed. One-port and two-port model of LC VCO is reviewed and well-known development idea of differential LC VCO is introduced. To provide basic knowledge about VCO phase noise, some VCO phase noise mechanism and important phase noise analysis methods are summarized. Chapter 4 introduces proposed quadrature generation method. A new super-harmonic coupling method is introduced for low power low phase noise quadrature generation. Low phase noise performance is obtained by eliminating phase noise contribution ...