A microchip (300) for driving a resonant circuit, wherein the resonant circuit is an LC tank, an antenna or a piezoelectric transducer, and wherein the microchip (300) is a single unit which comprises a plurality of interconnected embedded components and subsystems comprising at least an oscillator (315), a pulse width modulation (PWM) signal generator subsystem (329), an analogue to digital converter (ADC) subsystem (318) and a digital to analogue converter (DAC) subsystem (327).

A microchip (300) for driving a resonant circuit, wherein the resonant circuit is an LC tank, an antenna or a piezoelectric transducer, and wherein the microchip (300) is a single unit which comprises a plurality of interconnected embedded components and subsystems comprising at least an oscillator (315), a pulse width modulation (PWM) signal generator subsystem (329), an analogue to digital converter (ADC) subsystem (318) and a digital to analogue converter (DAC) subsystem (327).

An apparatus for transmitting ultrasonic waves, the apparatus including a microchip (300) for driving a resonant circuit and a resonant circuit which is at least one of an inductance (L) capacitance (C) circuit (LC tank), an antenna and a piezoelectric transducer. The microchip (300) is a single unit which includes a plurality of interconnected embedded components and subsystems including at least an oscillator (315), a pulse width modulation (PWM) signal generator subsystem (329), an analogue to digital converter (ADC) subsystem (318) and a digital to analogue converter (DAC) subsystem (327).

An apparatus for transmitting ultrasonic waves, the apparatus including a microchip (300) for driving a resonant circuit and a resonant circuit which is at least one of an inductance (L) capacitance (C) circuit (LC tank), an antenna and a piezoelectric transducer. The microchip (300) is a single unit which includes a plurality of interconnected embedded components and subsystems including at least an oscillator (315), a pulse width modulation (PWM) signal generator subsystem (329), an analogue to digital converter (ADC) subsystem (318) and a digital to analogue converter (DAC) subsystem (327).

The ultrasonic tubular transducer is activated at the centre thereof by two symmetrical electromechanical converters. The vibration generated by the two electromechanical converters is converted and then transmitted to the tube via a coupler. The ultrasonic transducer can be vibrationally isolated from the interfaces thereof by caps equally suitable for connecting the transducer to a stationary frame, a free end or another similar ultrasonic transducer. A device for pre-stressing electromechanical converters has a hole bored at the centre thereof in order to allow cables from the transducer as well as from adjacent transducers to pass therethrough.

The ultrasonic tubular transducer is activated at the centre thereof by two symmetrical electromechanical converters. The vibration generated by the two electromechanical converters is converted and then transmitted to the tube via a coupler. The ultrasonic transducer can be vibrationally isolated from the interfaces thereof by caps equally suitable for connecting the transducer to a stationary frame, a free end or another similar ultrasonic transducer. A device for pre-stressing electromechanical converters has a hole bored at the centre thereof in order to allow cables from the transducer as well as from adjacent transducers to pass therethrough.

An ultra-wide bandwidth acoustic transducer may include multiple layers, including an inner piezoelectric layer, a polymer coupling layer and an outer piezoelectric layer. The polymer layer may be located between, and may be bonded to, the inner and outer piezoelectric layers. The transducer may have multiple eigenfrequencies of vibration. These eigenfrequencies may include primary resonant frequencies of the inner and outer piezoelectric layers respectively and may also include resonant frequencies that arise due to coupling between the layers. An acoustic backscatter system may employ such a transducer in backscatter nodes as well as in a transmitter. The multiple eigenfrequencies may enable the system to perform spread-spectrum communication at a high throughput. These multiple eigenfrequencies may also enable each backscatter node to shift frequency of an uplink signal, which in turn may enable the system to mitigate self-interference and to decode concurrent signals from multiple backscatter nodes.

An ultra-wide bandwidth acoustic transducer may include multiple layers, including an inner piezoelectric layer, a polymer coupling layer and an outer piezoelectric layer. The polymer layer may be located between, and may be bonded to, the inner and outer piezoelectric layers. The transducer may have multiple eigenfrequencies of vibration. These eigenfrequencies may include primary resonant frequencies of the inner and outer piezoelectric layers respectively and may also include resonant frequencies that arise due to coupling between the layers. An acoustic backscatter system may employ such a transducer in backscatter nodes as well as in a transmitter. The multiple eigenfrequencies may enable the system to perform spread-spectrum communication at a high throughput. These multiple eigenfrequencies may also enable each backscatter node to shift frequency of an uplink signal, which in turn may enable the system to mitigate self-interference and to decode concurrent signals from multiple backscatter nodes.

A prosthesis including an implantable component including an LC circuit, wherein a piezoelectric material forms at least a part of the capacitance portion of the LC circuit, the piezoelectric material expands and/or contracts upon the application of a variable magnetic field to the inductor of the LC circuit, the LC circuit has an electrical self-resonance frequency below 20 kHz, and the piezoelectric material forms part of an actuator configured to output a force to tissue of a recipient in which the implantable component is implanted.

A prosthesis including an implantable component including an LC circuit, wherein a piezoelectric material forms at least a part of the capacitance portion of the LC circuit, the piezoelectric material expands and/or contracts upon the application of a variable magnetic field to the inductor of the LC circuit, the LC circuit has an electrical self-resonance frequency below 20 kHz, and the piezoelectric material forms part of an actuator configured to output a force to tissue of a recipient in which the implantable component is implanted.