Title :
A voltage controlled oscillator using barium strontium titanate (BST) thin film varactor
Author :
Victor, Alan ; Nath, Jayesh ; Ghosh, Dipankar ; Boyette, Brian ; Maria, Jon-Paul ; Steer, Michael B. ; Kingon, Angus I. ; Stauf, Gregory T.
Author_Institution :
Electr. & Comput. Eng. Dept., North Carolina State Univ., Raleigh, NC, USA
Abstract :
Barium strontium titanate (BST) has a field-dependent permittivity and can be used as a dielectric in voltage tunable capacitors or varactors. These BST-based varactors are passive devices and have significantly different properties compared to semiconductor varactors. A voltage tunable oscillator using a BST thin film varactor was designed and characterized. The frequency of oscillation varied from 34.8 MHz to 44.5 MHz (28% tuning) upon application of 7 V tuning voltage. The VCO gain was 1.38 MHz/V and the 2nd harmonic was over 23 dB below the fundamental throughout the tuning range.
Keywords :
VHF oscillators; barium compounds; circuit tuning; ferroelectric capacitors; harmonic distortion; permittivity; strontium compounds; thin film devices; varactors; 34.8 to 44.5 MHz; 7 V; BST thin film varactor; BaSrTiO3; ferroelectric films; field-dependent permittivity; harmonic distortion; passive varactors; tuning range; varactor dielectric; voltage controlled oscillator; voltage tunable oscillator; Barium; Binary search trees; Dielectric thin films; Semiconductor thin films; Strontium; Titanium compounds; Transistors; Tuning; Varactors; Voltage-controlled oscillators;
Conference_Titel :
Radio and Wireless Conference, 2004 IEEE
Print_ISBN :
0-7803-8451-2
DOI :
10.1109/RAWCON.2004.1389079
