QUARTZ SUBSTRATE ORIENTATIONS FOR COMPACT MONOLITHIC DIFFERENTIAL TEMPERATURE SENSOR, AND SENSORS USING SAME

摘要

Quartz cuts are provided which exhibit temperature characteristics which are favorable for making differential SAW temperature sensors. Families of Y cuts rotated between 0° and 60° degrees in combination with placement of two resonators at specified angles to each other are disclosed. Further, preferred embodiments in which the resonators are placed on opposite sides of a zero TCF line are disclosed, to provide wide temperature differences while efficiently utilizing the available bandwidth. The design permits placement of the resonator at angles smaller than 12.5° and even less than 5° therebetween, most preferably on quartz rotated Y cut between 28.5° and 42.75°.

主权项

1. A Surface Acoustic Wave (SAW) device comprising:
a plurality of SAW elements, comprising at least a first SAW element and a second SAW element, fabricated on a cut of quartz selected from the group consisting of: the families having |Φ| substantially zero; 0°≦θ≦55°; and rotational equivalents thereof, wherein said first SAW element has a propagation direction aligned with ψPSAW and said second SAW element has a propagation direction aligned with ψNSAW and wherein |ψPSAW| and |ψNSAW| obey the constraints:
28.5°+0.365*θ≦↓ψPSAW↓, |ψPSAW|<|ψNSAW|, ↓ΨNSAW↓≦37.0+0.310*θ,1.8°≦↓ψNSAW↓−↓ψPSAW↓≦8.5°,and rotational equivalents thereof.