Shear Mode Polarity Inverted ScAIN Multilayer for Application to Transformer in Rectifying Antenna

Increasing demand for wireless sensors has generated considerable recent research interest aiming at harvesting energy from surrounding electromagnetic wave. Low RF-to-DC conversion efficiency in the rectenna due to a weak RF input signal is a largely unsolved problem. Here we introduce the piezoelectrically induced shear stress inverted FBAR transformer, which combines the features of FBAR and piezoelectric transformer, to overcome this problem. In this paper, we applied the techniques of glancing angle sputtering deposition to grow a 12-layer c-axis zig-zag ScAIN film. c-Axis zig-zag structure was clearly observed by scanning electron microscopy. c-Axis tilt angles of the layers were determined to be 51-53 degrees by XRD analysis. The 12-layer ScAIN film HBAR excites 12th-order shear mode at 2.45 GHz. This new type of material has potential for use as a GHz voltage transformer in the rectenna.