Motorola Corporation

Beverly A Carroll

James Frank Caruba

Charles L Zimnicki

Sang Hoon Kim

John E Mattson

Weiping Zhang

A piezoelectric resonator (10) with electrodes (14) having a periodic pattern (28) along a portion of an edge (30) of at least one of the electrodes (26). The periodic pattern (28) has a periodicity that destructively interferes with the undesirable vibrational mode. For example, a rectangular AT-cut quartz resonator, which vibrates in a thickness-shear mode may also possess undesirable flexure and face-shear modes. These modes not only present undesirable spurious frequencies, they also change over temperature, disturbing a frequency-temperature response (16) of the quartz crystal. The periodic pattern (28) substantially reduces these undesirable modes, providing a more uniform frequency-temperature response which is beneficial in temperature compensated crystal oscillator applications.

Electrode edge wave patterns for piezoelectric resonator

A resonator (104) including a piezoelectric plate (102) with an electrode (108) having a random pattern (100) along a portion of an edge of the electrode (108). The random pattern (100) dampens or destructively interferes with undesirable and inharmonic vibrational modes. For example, a rectangular AT-cut quartz resonator, which vibrates in a thickness-shear mode may also possess undesirable flexure and face-shear modes. These modes not only present undesirable spurious frequencies, they also change over temperature, disturbing a frequency-ternperature response of the resonator. The random pattern (100) causes diffuse and/or specular scattering to reduce these undesirable modes, providing a more uniform frequency-temperature response which is beneficial in temperature compensated crystal oscillator applications.

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Marengo, IL, United States of America

Beverly A Carroll