A generator for generating electrical signal waveforms, the generator comprising a digital processing circuit, a memory circuit in communication with the digital processing circuit, the memory circuit defining first and second lookup tables, a digital synthesis circuit in communication with the digital processing circuit and the memory circuit, and a digital-to-analog, DAC, circuit, the generator configured to: store, by the digital processing circuit, phase points of a first digital electrical signal waveform in a first lookup table defined by the memory circuit, wherein the first digital electrical signal waveform is represented by a first predetermined number of phase points, wherein the first predetermined number of phase points define a first predetermined wave shape; store, by the digital processing circuit, phase points of a second digital electrical signal waveform in a second lookup table defined by the memory circuit, wherein the second digital electrical signal waveform is represented by a second predetermined number of phase points, wherein the second predetermined number of phase points define a second predetermined wave shape; and receive a clock signal by the digital synthesis circuit, and at each clock cycle: retrieve, by the digital synthesis circuit, a phase point from the first lookup table; retrieve, by the digital synthesis circuit, a phase point from the second lookup table; further characterized in that the generator is configured to combine, by the digital processing circuit, the phase point from the first lookup table with the phase point from the second lookup table to generate a combined phase point; and convert, by the DAC circuit, the combined phase point into an analog signal; wherein the analog signal is configured to drive a first and second ultrasonic transducer. store, by the digital processing circuit, phase points of a first digital electrical signal waveform in a first lookup table defined by the memory circuit, wherein the first digital electrical signal waveform is represented by a first predetermined number of phase points, wherein the first predetermined number of phase points define a first predetermined wave shape; store, by the digital processing circuit, phase points of a second digital electrical signal waveform in a second lookup table defined by the memory circuit, wherein the second digital electrical signal waveform is represented by a second predetermined number of phase points, wherein the second predetermined number of phase points define a second predetermined wave shape; and receive a clock signal by the digital synthesis circuit, and at each clock cycle: retrieve, by the digital synthesis circuit, a phase point from the first lookup table; retrieve, by the digital synthesis circuit, a phase point from the second lookup table; further characterized in that the generator is configured to combine, by the digital processing circuit, the phase point from the first lookup table with the phase point from the second lookup table to generate a combined phase point; and convert, by the DAC circuit, the combined phase point into an analog signal; wherein the analog signal is configured to drive a first and second ultrasonic transducer. retrieve, by the digital synthesis circuit, a phase point from the first lookup table; retrieve, by the digital synthesis circuit, a phase point from the second lookup table; further characterized in that the generator is configured to combine, by the digital processing circuit, the phase point from the first lookup table with the phase point from the second lookup table to generate a combined phase point; and convert, by the DAC circuit, the combined phase point into an analog signal; wherein the analog signal is configured to drive a first and second ultrasonic transducer.