| 摘要 |
PURPOSE:To provide a surface acoustic wave oscillator by which a desired signal with small spurious radiation and a high frequency is obtained without the use of an expensive component such as a band pass filter. CONSTITUTION:A surface acoustic wave resonator 2 is formed by arranging two interdigital transducers 12,14 on a piezoelectric substrate 4 at positions causing a phase difference of pi-radian for a prescribed frequency f0. Circuit 24,26 are oscillated at the prescribed frequency f0 with cooperation of the interdigital transducers 12,14. Then outputs of the circuits 24,26 have a phase difference of pi-radian because the interdigital transducers 12,14 are arranged at positions causing a phase difference of m-radian. A computing element 28 multiplies two signals whose frequency is f0 and whose phase difference is pi-radian outputted from the oscillators 24,26 with each other to output a signal whose frequency is 2f0 being a multiple of two of the frequency f0. Thus, a desired signal with a high frequency and small spurious radiation is obtained inexpensively. |
