Title :
Analysis of an Active Capacitance Circuit and Its Application to VCO
Author :
Cho, Sang-June ; Cho, Young-Ho ; Back, Hyung-Il ; Yun, Sang-Won
Author_Institution :
Dept. of Electron. Eng., Sogang Univ., Seoul
Abstract :
This paper presents an active capacitance circuit using a LC series-feedback scheme. The noise performance is excellent and the good stability is accomplished by adjusting the feedback elements. We analyze the circuit performances in detail and apply it to a voltage controlled oscillator. The active capacitance circuit provides negative resistance that can compensate not only the loss of varactor diode but also the parasitic resistance of inductor. A VCO employing the active capacitance circuit is designed at 2.179-2.191 GHz and the phase noise is -104.67dBc/Hz at 10 kHz offset within the tuning range
Keywords :
UHF oscillators; capacitance; voltage-controlled oscillators; 10 kHz; 2.179 to 2.191 GHz; LC series-feedback scheme; active capacitance circuit analysis; inductors; negative resistance circuits; parasitic resistance; varactor diode loss; voltage controlled oscillator; Active inductors; Circuit analysis; Circuit noise; Circuit stability; Diodes; Feedback; Parasitic capacitance; Performance analysis; Varactors; Voltage-controlled oscillators; Active circuits; bipolar transistors; negative resistance circuits; varactors; voltage controlled oscillators;
Conference_Titel :
Microwave Symposium Digest, 2006. IEEE MTT-S International
Conference_Location :
San Francisco, CA
Print_ISBN :
0-7803-9541-7
Electronic_ISBN :
0149-645X
DOI :
10.1109/MWSYM.2006.249743
