Abstract: An oscillator or a sensor comprising a unit including two frequency determining elements each of which comprises at least one interdigital converter for acoustic surface waves and a back-coupling circuit comprising an amplifier, wherein the frequency determining elements are distinguished by a temperature dependence of a synchronous frequency.

Abstract: The invention relates to an oscillator containing two one-port surface wave resonators as frequency-determining elements. The aim of the invention is to modify known oscillators such that the variable /S21/ for the oscillator frequency, that is adapted according to the respective temperature, only slightly depends on the temperature. The inventive oscillator is characterized in that, in relation to a pre-determined temperature, the first-order temperature coefficients of the synchronous frequency of the two one-port surface wave resonators (2; 3; 12; 13; 42; 43) have different signs or are equal to zero, and the second-order temperature coefficients of the synchronous frequency of the two one-port surface wave resonators have the same signs. The circuit consisting of the two one-port surface wave resonators is either two-terminal or four-terminal.