Temperature Compensated ZnO/SiO2/Si Thin Film Resonator for VHF Voltage Controlled Oscillator

Abstract

A new temperature compensated thin film resonator, consisting of a ZnO/SiOz/Si triple layer membrane, has been developed for application in a VHF voltage controlled oscillator (VCO). A t a 150 to 170 MI-Iz frequency range, resonators having desirable characteristics, such a s 40 ohms or less resonance resistance, 5 ppml"C or less temperature coefficient and 70 to 90 capacitance ratio, have been realized. A Colpitts VCO was constructed for use a t 160 hlIIz, using the ZnOISiOz/Si resonator and a varactor diode. A 340 ppm frequency deviation has been obtained versus a control voltage change from 0 to 4 V: which is in good agreement with the equivalent circuit analysis.