Temperature compensated surface acoustic wave oscillators

Claim 1

A surface acoustic wave oscillator which comprises a resonator circuit formed of a plurality of parallel-connected surface acoustic wave resonators indicating turnover temperatures on different curves denoting frequency deviations relative to ambient temperature, each said surface acoustic wave resonator being formed of a pair of interdigital electrodes which are mounted on a substrate for propagating a surface acoustic wave, and whose electrode elements are arranged alternately adjacent to each other; and an active element-containing circuit connected to the resonator circuit, wherein the plurality of surface acoustic wave resonators are so constructed that the relationship between the different frequencies of said resonators and the frequency deviations thereof and the relationship between the different turnover temperatures satisfy the following formulas: f.sub.H -f.sub.L ≦Δfa T.sub.p1 < . . . <T.sub.pn where f H : a maximum frequency among those frequencies of a plurality of resonators collectively connected to the active element-containing circuit which are produced at turnover temperatures on a temperature curve; f L : a minimum frequency among those of said plurality of resonators; Δfa: allowable frequency deviation of the surface acoustic wave oscillator; T p1 to T pn : turnover temperatures corresponding to the respective surface acoustic wave resonators.