High frequency crystal oscillator and high frequency signal generating method

摘要

A high frequency oscillator according to the present invention is structured in a small size and prevents noise from taking place in a severe environment of which there is a large temperature change. In the high frequency oscillator according to the present invention, the levels of higher harmonic components are increased against the level of a fundamental wave of an oscillating circuit using a quartz-crystal element. Any component of the higher harmonic components is selected by a surface acoustic wave filter having a piezoelectric substrate that is a crystal substrate. The selected component is amplified and a high frequency oscillation output signal is obtained.