The silicon CMOS technology has been the mainstream integrated circuit technology for digital VLSI circuits. With the continued down-scaling of minimum gate length of MOSFET to the deep sub-micrometer regime, radio-frequency (RF) integrated circuits on silicon CMOS technology are achievable and have become of increasing importance. Driven by the strong demand for low-cost personal wireless communication system in the gigahertz range, the monolithic integration of both active and passive devices together with digital VLSI circuits is the goal of CMOS RF integrated circuits. In this thesis, the active and passive devices on two variations of silicon CMOS technology, namely silicon-on-sapphire (SOS) CMOS and bulk CMOS, are designed and characterized for RF integrated circuits....[ Read more ]

The silicon CMOS technology has been the mainstream integrated circuit technology for digital VLSI circuits. With the continued down-scaling of minimum gate length of MOSFET to the deep sub-micrometer regime, radio-frequency (RF) integrated circuits on silicon CMOS technology are achievable and have become of increasing importance. Driven by the strong demand for low-cost personal wireless communication system in the gigahertz range, the monolithic integration of both active and passive devices together with digital VLSI circuits is the goal of CMOS RF integrated circuits. In this thesis, the active and passive devices on two variations of silicon CMOS technology, namely silicon-on-sapphire (SOS) CMOS and bulk CMOS, are designed and characterized for RF integrated circuits.

For the SOS technology, RF circuit performances of both active and passive devices on a 0.5-μm process are compared with those of a 0.5-μm bulk CMOS counterpart. From the experimental results, the SOS technology shows better inductor quality factor (Q) of 3 to 4 times improvement. The usable frequency range however lies only in the range of 2-6GHz. Further, the noise performance of the floating-body SOS MOSFET is in general inferior to that of the bulk CMOS by 1dB. It degrades further at the post DC kink region due to floating body effects. The power amplification of floating-body SOS MOSFET, both small signal and large signal, is not affected by the floating body. The RF power characteristics of the floating-body SOS MOSFET are investigated. The testing results show that the potential application of the SOS power amplifier to the low-transmission power systems.

For bulk silicon CMOS, a compact and expandable waffle layout is proposed to design wide MOSFET for RF integrated circuits. This new layout method provides significant area saving together with reduced gate resistance and source/drain diffusion capacitances. Waffle MOSFETs are fabricated with a standard 0.35-μm CMOS technology. The measurement results show a 2GHz higher f_max and 2dB higher MSG/MAG compared with the conventional multifinger MOSFET. An RF passive mixer was implemented with the waffle MOSFET design showing better conversion gain and possible higher IF bandwidth without any sacrifice of other performance parameters.