Membrane transducer with improved bandwidth

An ultrasonic transducer comprising:

• at least a first membrane configured to exhibit a first vibration to transceive ultrasonic waves;
• an electronic circuit coupled to the first membrane and configured to transceive electrical signals causing, or caused by, the first vibration;
• and
• a control element disposed on a first side of the first membrane and configured to induce a displacement asymmetry, in a motion of the first membrane during the first vibration, to the first side compared to a second side opposite the first side,
• wherein the control element comprises a second membrane disposed parallel to the first membrane with a closed pocket there between, wherein the closed pocket contains a fluid, resisting compression when the closed pocket contracts, causing a non-linear force on the first membrane as a function of its displacement towards the second membrane for inducing the displacement asymmetry.