SAW – Surface Acoustic Waves

Planar waves

Surface acoustic waves have received considerable attention recently and many devices are now being incorporated in electronic systems, sensors, bio-devices, and touchscreen displays.

Measurement of waves geometry, amplitude, homogeneity, are needed to investigate new design and to optimize devices geometries for new applications.

The Holographic MEMS Analyzer is the perfect instrument to address such measurement. The high vertical and lateral resolution enable to resolve wave propagation overt he entire field of view.

Description

  • DHM R1003, magnification 20x
  • Operating frequency : 24.7 MHz
  • Courtesy of SAWLab Saxony, IFW Desden, Germany

Vibrations sequence and vibrations maps

Vibrations amplitude is smaller than topography features with 5 nm versus 150 nm. Computing vibrations sequence enables the visualization.

Full field of view measurement and high vertical resolution provide immediately a dynamical representation of surface 3D acoustic wavefield. It enables to investigate

  • SAW homogeneity and amplitude
  • Edge effects
Dynamic topography recorded @ 24.7 MHz
Vibrations sequence @ 24.7 MHz
Amplitude vibration map@ 24.7 MHz
Phase vibration map @ 24.7 MHz

Novel pMUT design

  • Courtesy of  : University of California, Davis, CA, USA
  • Device : Coupled piezoelectric micro-machined ultrasonic transducers
  • DHM® : R-1003, magnification 10x
  • Excitation frequency : 10 MHz
  • Wave from : sinus, 10 Vpp

Vibration analysis

Out-of-plane vibrations enable analysis of device vibration at a given frequency. Amplitude and phase map give information on the generated acoustic wave. The phase map shows a spherical wave generated, amplitude gives information about wave amplitude, homogeneity and attenuation.

Dynamic topography : vibrations has a smaller amplitude than topography features
Out-of-plane vibrations sequence : vibrations amplitude is 1 nm peak to peak
Amplitude vibration map @ 10 MHz
Phase vibration map @ 10 MHz

Publikationen

Coupled piezoelectric micromachined ultrasonic transducers with improved pulse-echo performance – IEEE Conference Publication

Coupled piezoelectric micromachined ultrasonic transducers with improved pulse-echo performance – IEEE Conference Publication

Novel pMUT design

  • Courtesy of  : University of California, Davis, CA, USA
  • Device : Coupled piezoelectric micro-machined ultrasonic transducers
  • DHM® : R-1003, magnification 5x
  • Excitation frequency : 10 MHz
  • Wave form : Sinus, 10 Vpp

Vibration analysis

Amplitude and phase map give information on the generated acoustic wave. A planar wave is generated on each side of the device, destructive interference occurs in the corners.

Dynamic Topography
Vibrations sequence
Amplitude vibration map
Phase vibration map