Analysis of the RC Phase-shift Oscillator

The RC phase-shift oscillator is a simple and commonly used RC type sinusoidal oscillator with low frequency. Due to the analysis process of the RC phase-shift oscillator circuit is so complicated and the start-oscillation condition is so strict that the analysis process of the oscillation frequency also become complicated. That's the reason why this circuit is now hardly analyzed detailedly in the series of papers of analogue circuit, and just presented the oscillating frequency of an oscillating circuit, and different paper have different results which lead to many troubles for users. In this paper, the RC phase-shift oscillator is analyzed in detail based on oscillation principle of sinusoidal oscillation circuit. The general formula of oscillating frequency and current amplification factor of the transistor are derived from this paper, and the oscillating condition and analytical method of this circuit are also given. Meanwhile, the defect existing in some reference is pointed out.