AN 800-MHz LC-VCO WITH A LINEAR CONTROL CHARACTERISTICS IN A 130-nm CMOS TECHNOLOGY

摘要

A semilinear LC-voltage-controlled oscillator (VCO) topology is proposed. To exploit a linear frequency tuning, the LC-VCO adopts the variable capacitance block of the varactor devices and the PMOS transistors. This block has the capacitance characteristics which are approximately inversely proportional to the square of the VCO control voltage. The proposed LC-VCO is implemented in a 130-nm CMOS technology. The measurement results show a semilinear frequency range of 503-873 MHz and a phase noise of -128 dBc/Hz at 1 MHz offset frequency. Power consumption is about 2 mA from a 1.2 V supply.