Title :
A 5-GHz self-calibrated I/Q clock generator using a quadrature LC-VCO
Author :
Ahn, Hyung Ki ; Park, In-Cheol ; Kim, Beomsup
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., Korea Adv. Inst. of Sci. & Technol., Daejeon, South Korea
Abstract :
This paper describes a self-calibration technique to generate precise I/Q signals for frequency synthesis. The phase comparator compares the in-phase signal to the quadrature signal in the quadrature LC-VCO and the charge-pump circuit produces the correction voltage. To verify the functionality of the proposed scheme, the 5-GHz LC quadrature VCO utilized in 5-GHz band wireless LAN, especially, IEEE 802.11a, is designed. The phase error resulting from calibration is under 2-degree in various device mismatches. The oscillator with calibration achieves -121.5 dBc/Hz at 1 MHz offset and exhibits 10 % tuning range. A prototype frequency synthesizer using the proposed scheme is also designed using a 0.18-μm 1-poly, 6-metal standard CMOS process and verified with schematic simulation.
Keywords :
CMOS integrated circuits; calibration; clocks; frequency synthesizers; phase comparators; voltage-controlled oscillators; wireless LAN; 0.18 micron; 5 GHz; CMOS frequency synthesizer; I/Q clock generator; IEEE 802.11a; charge pump circuit; phase comparator; phase error; quadrature LC-VCO; self-calibration; wireless LAN; Calibration; Charge pumps; Circuit synthesis; Clocks; Frequency synthesizers; Signal generators; Signal synthesis; Voltage; Voltage-controlled oscillators; Wireless LAN;
Conference_Titel :
Circuits and Systems, 2003. ISCAS '03. Proceedings of the 2003 International Symposium on
Print_ISBN :
0-7803-7761-3
DOI :
10.1109/ISCAS.2003.1205684