Amplifier circuit for a parametric transducer and a related audio device
AssigneeNanyang Technological University
InventorsJoseph Sylvester Chang, Tong Ge, Linfei Guo
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Abstract
An amplifier circuit for a parametric transducer, comprising: a signal processor for processing an input signal into first and second signals; and at least a pair of output stages arranged to respectively receive the first and second signals for generating amplified first and second signals respectively, which are provided to operate the parametric transducer. The input, first and second signals are arranged with a substantially similar frequency to cause a switching frequency of the amplifier circuit to be matched to a carrier frequency of the parametric transducer. A related audio device is also disclosed.
Claims9
An audio device comprising:
- (i) first and second parametric transducers for generating respective first and second output audio signals having an output carrier frequency;
- (ii) a signal processor for processing an input modulated signal into first and second signals with different phase-shifts, the input modulated signal being produced from modulation of a carrier signal by an input audio signal, the carrier signal having a same frequency as the output carrier frequency of the first and second parametric transducers;
- and
- (iii) first and second pairs of amplifier output stages arranged to respectively receive the first and second signals for generating first and second pairs of amplified signals to operate the first and second parametric transducers to generate corresponding first and second ultrasonic signals with the phase-shifts, the first and second ultrasonic signals serving respectively as the first and second output audio signals,
- wherein the signal processor, and the amplifier output stages collectively form an amplifier circuit;
- wherein the input modulated signal and the first and second signals are arranged with a substantially similar frequency to cause a switching frequency of the amplifier circuit to be matched to the output carrier frequency of the first and second parametric transducers;
- and
- wherein the first and second parametric transducers are arranged to direct the respective first and second ultrasonic signals towards a common area in the air to cause interaction of the first and second ultrasonic signals within the common area to obtain an audible audio signal.
Dependencies are inferred from the claim text.