Title :
Q - Enhanced 5GHz CMOS VCO Using 4-port Transformer
Author :
Lee, Young Jae ; Kim, Cheon Soo
Author_Institution :
RF/Analog SoC Design Team, ETRI, Daejeon
Abstract :
The LC VCO having oscillation frequency of 5GHz and using the transformer-coupled LC tank in 0.13 mum CMOS technology is developed. The LC tank that employs the drain-gate transformer feedback configuration is composed of a 4-port transformer and varactor diodes. The transformer has the quality factor increased by 1+k where k is the coupling factor between each port and it is characterized to propose the equivalent circuit for the 2-port transformer using the measured S-parameters. The measured phase noise of LC VCO is -110dBc/Hz at the offset frequency of 1MHz and the tuning range of 450MHz is achieved
Keywords :
CMOS integrated circuits; Q-factor; circuit feedback; microwave integrated circuits; microwave oscillators; phase noise; transformers; varactors; voltage-controlled oscillators; 0.13 micron; 4-port transformer; 450 MHz; 5 GHz; CMOS technology; LC VCO; LC resonators; Q-enhanced CMOS VCO; S-parameters; equivalent circuit; phase noise; quality factor; transformer feedback configuration; transformer-coupled LC tank; varactor diodes; voltage controlled oscillator; CMOS technology; Coupling circuits; Diodes; Equivalent circuits; Feedback; Frequency; Q factor; Scattering parameters; Varactors; Voltage-controlled oscillators; CMOS; LC resonators; quality factor; transformer; voltage controlled oscillator;
Conference_Titel :
Silicon Monolithic Integrated Circuits in RF Systems, 2007 Topical Meeting on
Conference_Location :
Long Beach, CA
Print_ISBN :
0-7803-9764-9
Electronic_ISBN :
0-7803-9765-7
DOI :
10.1109/SMIC.2007.322795
