Abstract ▼ AI-Helper

Wireless communications have progressed remarkably in the last decade. The popularization of cellular phones has driven much of the research activity. CMOS technology provides such advantages as low cost, high-level integration, and easy access over other technologies. Above all, the CMOS technology...

Wireless communications have progressed remarkably in the last decade. The popularization of cellular phones has driven much of the research activity. CMOS technology provides such advantages as low cost, high-level integration, and easy access over other technologies. Above all, the CMOS technology makes it possible to integrate RF circuits, analog circuits, and digital base band circuits on a single chip, which makes an ultimate one-chip system (or system on a chip). The growing demand for mobile communications, mainly telephony, implies the need for better performance of RF transceiver architectures. Especially, the VCO is the most important block of RF front-end of the transceiver because it operates at a high frequency and requires a low phase noise. The main characteristics of a VCO are its phase noise and tuning range. The output of a VCO is needed in image-rejection receiver or direct-conversion transceiver. Recently, finding out the solution of how to obtain lower phase noise characteristics, how to generate quadrature signals, have been hot issues.
This thesis presents the circuit design, simulation and measurement results for a CMOS VCO with LC tank circuit. It was designed for single-chip integration of CMOS RF receiver based on the 0.25㎛ CMOS process. LC tank is based on on-chip inductor and MOS varactor. With 2.5V power supply voltage and power dissipation of 7.5mW, the VCO showed a phase noise of -116dBc/Hz at 1MHz frequency offset over the tuning range of 2.471~2.929GHz. And all simulation and implementation is based on a standard CMOS technology.

Keyword