Title :
A high frequency harmonic VCO with an artificial varactor
Author :
Stadius, Kari ; Kaunisto, Risto ; Porra, Veikko
Author_Institution :
Inst. of Radio Commun., Helsinki Univ. of Technol., Espoo, Finland
Abstract :
A tunable LC-oscillator utilising an artificial varactor is presented in this paper. The proposed variable capacitor is based on the well-known Miller effect. A theoretical model is developed to study the capacitance tuning range and the corresponding Q-value. Most radio frequency harmonic voltage-controlled oscillators are tuned by changing the capacitance of a pn-junction diode. The inadequate capacitance tuning range of the pn-junction diode severely limits the achievable frequency tuning range of the oscillator. By using an artificial varactor based on the Miller capacitance, the frequency tuning range is enhanced significantly. The proposed LC-VCO has a tuning range of 1.7-2.2 GHz
Keywords :
BiCMOS analogue integrated circuits; Q-factor; UHF integrated circuits; UHF oscillators; capacitance; circuit tuning; harmonic oscillators (circuits); integrated circuit design; integrated circuit modelling; varactors; voltage-controlled oscillators; 1.7 to 2.2 GHz; BiCMOS process; Miller capacitance; Q-value; artificial varactor; capacitance tuning range; frequency tuning range enhancement; high frequency harmonic VCO; model; radio frequency harmonic voltage-controlled oscillators; tunable LC-oscillator; variable capacitor; Capacitance; Capacitors; Circuit optimization; Frequency; Impedance; Schottky diodes; Tuning; Varactors; Voltage; Voltage-controlled oscillators;
Conference_Titel :
Electronics, Circuits and Systems, 1998 IEEE International Conference on
Conference_Location :
Lisboa
Print_ISBN :
0-7803-5008-1
DOI :
10.1109/ICECS.1998.813958
