A crystalline semiconductor resonator device comprises two matched resonators which are aligned differently with respect to the crystal structure of the crystalline semiconductor. The resonators each comprise a portion of a material having a different temperature dependency of the Young's modulus to the temperature dependency of the Young's modulus of the crystalline semiconductor material. In this way, the suspension springs for the resonators have different properties, which influence the resonant frequency. The resonant frequency ratios between the first and second resonators at a calibration temperature and an operation temperature are measured. A frequency of one (or both) of the resonators at the operation temperature can then be derived which takes into account the temperature dependency of the one of the resonators.