Motorola Corporation

Cts Corporation

Jin Huang

Brian M Mancini

Pallab Midya

Charles L Zimnicki

John E Mattson

John Mattson

Jiashi Yang

Bruce Vojak

A piezoelectric resonator (10) includes a single crystal elongated plate (12) having a transverse extensional mode of oscillation. Two sets of split electrodes (20,22,30,32) are provided on the surfaces (14,16) of the plate (12) to define two acoustically coupled oscillating regions (24,26) therebetween. The oscillating regions (24,26) present a similar inductance and have similar performance to allow the use of the resonator (10) in a double-ended electrical transformer circuit (100). An AC source (112) drives non-opposing top and bottom electrodes of the resonator (110). The remaining electrodes are coupled with shunt capacitors to provide two resonant LC circuits with the resonator (110) so as to provide a voltage gain for driving a load.

Extensional mode piezoelectric crystal resonator with split electrodes

A high frequency acoustic wave piezoelectric device (10) having parallel etched channels cut into a surface of a piezoelectric substrate so as to form micromachined ridges (20). Top electrodes (30) are located on tops (26) of the ridges (20) and bottom electrodes (32) are located on bottoms of the channels in spacings (22) between ridges (20). The top and bottom electrodes (30, 32) are offset from each other and substantially non-opposing. The electrodes (30, 32) generate a sufficient vertical electrical field (38) when driven to cause the ridges (20) to resonate. A height (28) of the ridges (20) define the operating frequency. The ridges (20) can be made small enough to produce frequencies well over 100 MHz in a fundamental bulk acoustic wave mode.

Surface micromachined acoustic wave piezoelectric crystal with

A piezoelectric transformer (10) consisting of a single-crystal elongated plate (12) with electrodes (20, 26). A pair of driving sections (22) are formed on two opposite end regions of the plate (12). A receiving section (24) is formed on a central region of the plate (12). The plate (12) is operated in an even harmonic vibrational mode with the driving sections (22) operating in a transverse extensional mode and the receiving section (24) operating in a length extensional mode. Driving signals (46, 48) applied to the driving sections (22) are at the resonant frequency of the plate (12). The gain of the transformer (10) is adjustable by shifting the relative phase of the driving signals (46, 48) applied to the respective driving sections (22).

Single crystal piezoelectric transformer using extensional vibration

A transformer circuit (10) for a piezoelectric transformer (12) having dual inputs which can piezoelectrically interfere with one another to provide adjustable output gain. The transformer circuit (10) provides two pulse-position-modulated input signals (18, 20) which are substantially identical waveforms, but being phase shifted from one another. When the signals (18, 20) constructively interfere maximum gain is achieved. When the two signals (18, 20) destructively interfere minimum gain is achieved. The waveforms may be of any arbitrary type including square, sine, triangle, sawtooth or irregular. Both input signals (18, 20) are at a resonant frequency of the piezoelectric transformer (12) and have a fifty percent duty cycle so as to always provide highest efficiency within the transformer (12). In addition, when the two input signals (18, 20) destructively interfere with each other piezoelectrically, the input impedance of the transformer (12) rises so as to lessen power dissipation within the transformer (12) which subsequently reduces adverse heating effects.

Driving circuit for multisectional piezoelectric transformers using

A piezoelectric transformer (10) operating in a thickness-shear vibration mode (26). The piezoelectric transformer (10) comprises a lithium niobate substrate (12) having first and second acoustically coupled portions (16,22), and a plurality of substantially opposing pairs of primary and secondary electrodes (14,20) disposed thereon. An input AC voltage applied to the primary electrode pairs (14) exciting a thickness-shear vibration (26) which couples to the secondary electrode pairs (20) producing an output AC voltage therebetween. The primary and secondary electrodes (14,20) being electrically connected in various combinations of parallel and series connections to provide a desired step-up or step-down voltage transfer ratio.

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Hoffman Estates, IL, United States of America

Jin Huang