New method of multy-mode oscillations control in crystal resonators

In resonators of standard construction of SC-cut motional resistance of temperature sensitive mode B is commensurable with motional resistance of main mode C that creates danger of oscillator excitation on mode B. In given work in-depth analysis of oscillation excitation in dual-rotated crystal cuts is provided. It is shown that standard central layout of electrodes for SC-cut resonators is not optimal. Results of calculations of motional resistance of the C and B modes of oscillations for standard (central) and displaced excitation electrodes are resulted. It is shown that at the correct choice of electrodes layout it is possible to change a ratio of modes resistances considerably that allows providing reliable excitation of main mode C.