Spectral purity of acoustic resonator oscillators

The spectral purity of state-of-the-art oscillators that use acoustic resonators in the frequency range of 5 to 500 MHz is surveyed, with the primary emphasis placed on oscillators that use bulk acoustic wave and surface acoustic wave devices on single crystal quartz. The phase noise characteristics of low-noise oscillators are analyzed in the context of Leeson's model of feedback oscillator phase noise, and particular attention is given to flicker frequency noise levels and white phase noise floors. Procedures and methods for reducing phase noise levels are discussed along with an analysis of reported attempts to obtain improved spectral purity.<>