AN ADVANCED ANALYSIS METHOD OF COLPITTS OSCILLATOR CIRCUIT

Abstract

Oscillator circuit is one of the most important components in communication devices. Although oscillator circuits have been used more popularly in practical, their analysis theory is still not enough accuracy for determining the oscillator frequency at high-frequency region. In basic, there are two basic parts of an oscillator circuit, an amplifier, and a feedback circuit. In recent analysis methods, the oscillator frequency was defined mostly based on L and C elements in the feedback circuit while these parasitic capacitances between the junctions of BJT transistors in high-frequency domain were nearly omitted. This creates a larger difference for analyzing and designing oscillator circuits at a predefined frequency in high-frequency region. This paper proposed an advanced analysis method which includes all parasitic capacities to increase the accuracy of determining the oscillator frequency of Colpitts oscillator circuit