Title :
Dual-resonance LC-tank frequency divider implemented with switched varactor bias
Author :
Chang, Chia-Wei ; Jang, Sheng-Lyang ; Huang, Chong-Wei ; Shih, Chih-Chieh
Author_Institution :
Dept. of Electron. Eng., Nat. Taiwan Univ. of Sci. & Technol., Taipei, Taiwan
Abstract :
A triple-band CMOS LC-tank injection locked frequency divider (ILFD) is proposed and implemented in a 90nm CMOS process. It is realized with a cross-coupled nMOS oscillator with a double-tuned transformer resonator. At the dc drain-source voltage of 0.65 V, the free-running ILFD can have two frequency bands while switching one varactor bias, and the tuning range is from 4.23 (8.89) GHz to 4.47 (10.39) GHz for the low- (high-) frequency band. The measured operational locking range is from 7.6 (15.3) GHz to 10 (19.9) GHz for the low- (high-) frequency band. The double-resonance ILFD has one excited locking frequency band while biasing at the high-frequency band, the excited operational locking range is from 5.75 GHz to 6.3 GHz.
Keywords :
CMOS integrated circuits; frequency dividers; oscillators; varactors; cross-coupled nMOS oscillator; double-tuned transformer resonator; dual-resonance LC-tank frequency divider; free-running ILFD; frequency 15.3 GHz to 19.9 GHz; frequency 4.23 GHz to 4.47 GHz; frequency 5.75 GHz to 6.3 GHz; frequency 7.6 GHz to 10 GHz; frequency 8.89 GHz to 10.39 GHz; size 90 nm; switched varactor bias; triple-band CMOS LC-tank injection locked frequency divider; voltage 0.65 V; Dual band; Frequency conversion; Resonant frequency; Tuning; Varactors; Voltage-controlled oscillators; 90 nm CMOS; dual-resonance resonator; injection locked frequency divider; oscillator; transformer;
Conference_Titel :
VLSI Design, Automation and Test (VLSI-DAT), 2011 International Symposium on
Conference_Location :
Hsinchu
Print_ISBN :
978-1-4244-8500-0
DOI :
10.1109/VDAT.2011.5783545
