A longitudinal (1−x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 single-crystal piezoelectric transformer

In present work, a simple longitudinal piezoelectric transformer with the size of 16-mm length, 2-mm width, and 2-mm thickness was designed and fabricated with relaxor ferroelectric single-crystal (1−x)Pb(Mg1/3Nb2/3)O3-xPbTiO3. Both the input and output parts utilized the ultrahigh longitudinal extensional electromechanical coupling coefficients. Compared to the Rosen-type transformer, this transformer has the advantages of smaller-size, simpler structure, no spurious vibration, and no acoustic mismatch between the input and output parts. The electrical measurement results indicated that under the resonance frequency of 114 kHz, a step-up voltage of about 30 can be obtained under a 10-MΩ load resistance, which agreed well with the calculated results. Besides, the frequency and load dependences of this transformer were also systematically studied and discussed. The results indicated that this transformer has potential applications in the small-size high-voltage amplifier and magnetoelectric/piezoelectric-transformer composite transducers.