An AT-cut quartz resonator is disclosed, wherein the length l, the width w and the thickness t of the quartz crystal plate are respectively chosen in the directions of an electrical axis (X-axis), an optical axis (Z'-axis) and a mechanical axis (Y'-axis), the width-to-thickness ratio w/t is chosen in the range of 2.0 to 2.8 and the length-to-thickness ratio l/t is chosen less than 25. Consequently, an AT-cut quartz resonator of miniature size having high Q-values of the major mode and excellent frequency-temperature characteristics of the vibration frequency is realized.

Single crystal quartz filter elements, oscillators and transducers

AT-Cut quartz resonator, with w/t=2.0 to 2.8, l/t<25

Mechanical resonating structures and related methods are described. The mechanical resonating structures may provide improved efficiency over conventional resonating structures. Some of the structures have lengths and widths and are designed to vibrate in a direction approximately parallel to either the length or width. They may have boundaries bounding the length and width dimensions, which may substantially align with nodes or anti-nodes of vibration.

Methods and apparatus for mechanical resonating structures

A resonator or filter which comprises a bar (1) of piezoelectric material provided with electrodes (2,3) which are spaced from the two ends of the bar. In operation, thickness shear vibrations occur between the electrodes and the bar width to thickness ratio is such that said vibrations in turn produce Nth harmonic flexure vibrations which propagate across the bar width, N being an even number. In order to accelerate the rate of decay of the vibrations towards the (supported and hence energy-absorbant) ends of the bar, and thus to reduce the distance between the electrodes and the ends of the bar for a given quality factor, (N/2-1) slots (4), some of which may be omitted, are provided in each of these ends so that each end is divided into N/2 prongs (5) of equal width.

Piezo-electric resonator or filter having slots formed which impede undesired vibrational energy

A surface-mountable crystal resonator (100) is provided in the following manner. A first predetermined electrode pattern (105) and a second predetermined electrode pattern (201) are formed on a first major surface (104) and a second major surface (200), respectively, of a piezoelectric crystal substrate (101). Additionally, a first predetermined attachment electrode pattern (106), electrically coupled to the second predetermined attachment electrode pattern, and a second predetermined attachment electrode pattern (202), electrically coupled to the first predetermined attachment electrode pattern, are formed on a first attachment area (102) and a second attachment area (103), respectively. The first and second attachment areas include extensions (107) that, when mounted, allow a conductive adhesive (301), placed on a mounting substrate (300), to flow and establish electrical connections with the first and second predetermined attachment electrode patterns.

Surface-mountable crystal resonator

A digital display electronic wristwatch including a quartz crystal high frequency time standard having a natural frequency in the MHz range is provided. The quartz crystal time standard is incorporated into an oscillator circuit that produces a high frequency time standard signal having the same frequency as the frequency of vibration of the time standard. A divider circuit is formed from a plurality of series-connected divider stages and produces a low frequency reference signal in response to the time standard signal. Series-connected counters are coupled to the divider to produce time-keeping signals in response to the low frequency reference signal being applied thereto, and digital display elements are adapted to display time in response to the time-keeping signals produced by the respective series-connected counters.

Single crystal quartz filter elements, oscillators and transducers

Citations

AT-Cut quartz resonator, with w/t=2.0 to 2.8, l/t<25

Methods and apparatus for mechanical resonating structures

Piezo-electric resonator or filter having slots formed which impede undesired vibrational energy

Surface-mountable crystal resonator

Digital display electronic wristwatch

References

High frequency crystals

Related Papers (5)

Fabrication of quartz resonators

Quartz resonators and oscillators

One-chip quartz crystal oscillator using a direct-bonding technique of quartz crystal onto silicon

Crystal oscillator manufacturing method

Current conveyor based sinusoidal oscillators employing quartz crystal resonators behaving as inductors