Resonance-mode selection and crosstalk elimination using resonator-synchronised relaxation oscillators

In many applications, electro-mechanical resonators, such as crystals or micro-machined resonating structures, are used as a frequency-selective element in oscillators. These mechanical resonators often have many resonance modes and suffer from large crosstalk. The reliable selection of the desired resonance mode, at the same time coping with the large crosstalk is often a problem in integrated circuits, especially when the spacing between resonance modes is only small. In this paper, a method is presented that uses the selectivity and the time-discrete character of relaxation oscillators to solve both problems.