Abstract: A new family of stress compensated quartz resonators having cuts exhibiting an ultra-linear frequency vs. temperature characteristic. This family of resonators has an orientation defined with respect to the crystallographic axes by polar angles .phi. and .theta., which angles lie on the locus where the second-order temperature coefficient of frequency is zero between the angles .phi.=20.degree..+-.2.degree. and .theta.=20.degree..+-.5.degree., and in close proximity to the locus of zero coefficient of stress. In one preferred embodiment, the resonator comprises a plate whose angles of cut .phi. and .theta. are both substantially equal to 20.degree.. In a second preferred embodiment an exact stress compensation is provided where .phi. is substantially equal to 20.8.degree. and .theta. is substantially equal to 23.2.degree., and orientation where the locus of the zero coefficient of stress intersects the locus of the zero of the second-order temperature coefficient.

Abstract: An arrangement is disclosed for piezoelectric resonators utilizing linear and parallel sides or flats located on the periphery and opposite ends of the resonator. These sides are located normal to the axes wherein collinear forces applied to the resonator produce a desired effect upon its natural resonant frequency. For mechanical sensor applications this effect is maximized while for applications requiring a stable frequency or time base this effect is minimized. The outline peripheral shape of the resonators utilizing this mounting arrangement varies in accordance with the crystallographic orientation present in each resonator.