An amplifier circuit to be used in a sonar is described. The amplifier circuit includes a transducer and a matching circuit. The transducer has an impedance characteristic having a resonance frequency and an anti-resonance frequency higher than the resonance frequency. The matching circuit is connected to the transducer. The impedance characteristic of the transducer connected to the matching circuit has a first resonance frequency and a second resonance frequency higher than the first resonance frequency.

The present invention relates to multi-stake underwater transducers and arrays for the generation and reception of sound waves in water. The invention provides the design and fabrication of compact piston-type underwater transducers of low-to-mid operating frequency made of piezoelectric single crystals without the need of any pre-stress mechanism. The invention uses a multi-stake pipe-like motor section made of piezoelectric single crystals of high transverse mode piezoelectric coefficients and low acoustic impedance, and small-diameter and light head mass(es). The present invention also discloses various means of increasing the bandwidth of the multi-stake underwater transducers as well as derivative transducers and arrays made of them, including compact 2D and 3D omni-directional transducers, planar, conforming and shaped arrays of various designs, high-density arrays and low-drop-down-ratio parametric arrays of either single or dual frequency bands.

Provided is a fixture for concentrically aligning and assembling a Ceramic Stack Assembly transducer during manufacturing. The CSA fixture comprises a base, a top compression cap, a central rod and a fastener, one or more alignment posts, and a driving wedge. The base further includes a groove to accept and align a transducer rear-centering ring at a central axis of the fixture. The transducer rear-centering ring supports one or more copper foil or ceramic rings during assembly. The alignment posts and driving wedge apply radial pressure to the copper foil or ceramic rings during assembly to force concentric alignment. The top compression cap, central rod, and fastener compress and stress the CSA Ceramic once assembled. The fixture simultaneously provides concentric alignment, foil alignment and provides a mechanism for stressing the CSA. A method of use is also provided.

An acoustic antenna intended to equip a sonar, the antenna being centred around a first longitudinal axis and includes at least a first assembly of at least two transducers and a second assembly of at least two transducers stacked along the longitudinal axis, each transducer having at least a radial mode having a resonance frequency, referred to as the radial frequency, and a cavity mode having a resonance frequency, referred to as the cavity frequency, wherein the transducers of the first assembly are configured to transmit sound waves in a first continuous frequency band extending at least between the cavity and radial frequencies of the transducers of the first assembly and the transducers of the second assembly are configured to transmit sound waves in a second continuous frequency band extending at least between the cavity and radial frequencies of the transducers of the second assembly, in that the cavity frequency of a transducer of the second assembly is equal to the radial frequency of a transducer of the first assembly plus or minus (fr1fc1)/10, fr1 being the radial frequency of the transducer of the first assembly and fc1 being the cavity frequency of the transducers of the first assembly and wherein the transducers of the second assembly are positioned between the transducers of the first assembly and in that no transducer of the first assembly is positioned between the transducers of the second assembly.

The present disclosure provides a cleaning robot comprising one or more motors and a controller configured to control the one or more motors to generate acoustic signals indicative of content. The controller is configured to control at least one of a frequency of the acoustic signals and a pulse width of acoustic pulses generated by the one or more motors. The controller may be configured to control the one or more motors to generate an ascending sequence of frequencies and to use a frequency of a pulse generated by the one or more motors to validate a pulse width of the pulse. The one or more motors are configured to transmit frequency tones that indicate bits of a first value within the content. The one or more motors comprise at least one of a pump motor and a drive motor, wherein the controller is configured to control electric power within a motor coil using pulse width modulation to generate the acoustic signals.

A transducer device that can generate a wide, ultra-wide, or wide-angle acoustic beam within or through water. The transducer device can include a transducer element configuration having an acoustic emission portion that has a concave shape for generating a series of acoustic beams that cross each other to collectively form a wide-angle acoustic beam.

Sonar systems and related methods are provided. A sonar system for generating one or more sonar images includes first and second transducer elements each having at least one emitting face. The sonar system also includes a sonar signal processor in electronic communication with the first and second transducer elements to cause transmission of signals from the first and second transducer elements to cause at least one first acoustic beam to be emitted from the first emitting face in a first beam direction and at least one second acoustic beam to be emitted from the second emitting face in a second beam direction. The first and second transducer elements are positioned such that a gap is formed therebetween. The gap is configured to facilitate movement of a fluid therein so as to contribute to an emission of sound power in both the first beam direction and the second beam direction.

A sonar transducer includes an acoustic radiating piston, a piezoelectric stack, and a non-uniform central fastener. The acoustic radiating piston emits and receives acoustic waves. The piezoelectric stack includes a plurality of piezoelectric elements. The piezoelectric stack converts output electrical signals into mechanical vibrations and converts received mechanical vibrations into input electrical signals. The non-uniform central fastener has a body extending from a first end to a second end to define a fastener length. The non-uniform central fastener extends through the piezoelectric stack and applies a pre-stress to the piezoelectric stack. The non-uniform central fastener has a non-uniform profile along the fastener length.