Fig. 4: The characterization of the PMUT.
From: High frame rate ultrasonic flowmeter based on PMUT array with bidirectional acoustic beams
a The electrical impedance of a single PMUT channel and five PMUT channels in parallel. b The electrical impedance of five discrete channels in a die. c The mechanical frequency response of the bilateral PMUT cells. d The mechanical frequency response of the centric PMUT cells. e The mechanical frequency response of a PMUT cell under various AC voltages. f The harmonic magnitude of the PMUT cell operating in the deep linear region, the turning point, and the non-linear region. g The mechanical frequency response of PMUT cells in a single channel that operate in linear region. h The mechanical frequency response of PMUT cells in a single channel that operate in non-linear region. i The displacement variation with AC voltages of PMUT cells in a single channel. j The resonant frequency variation with AC voltages of PMUT cells in a single channel. All of the vibration behaviors were excited through periodic chirp signals
