Modulator - amplifier
First Claim
1. A modulator-amplifier configured for use in parametric sound reproduction systems for reproducing audio information in a medium, comprising:
- an input configured for receiving at least one input signal including audio information;
at least one reference signal generator configured for generating at least one reference signal;
at least one comparator coupled to the input and the reference signal generator configured for detecting a relationship between a first signal based on the at least one input signal and the at least one reference signal and generating a second signal based thereon;
at least one switching power stage coupled to the at least one comparator and configured to receive the second signal and drive art output signal including at least one sideband and audio information; and
wherein the relationship between the at least one input signal and the timing of state transitions in the switching power stage is non-linear.
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Accused Products
Abstract
A modulator-amplifier configured for use in parametric sound reproduction systems, including an input configured for receiving at least one input signal, a reference signal generator configured for generating a reference signal, and a comparator stage coupled to the input and the reference signal generator, the comparator stage configured for detecting relationships between a first signal based on the input signal and the reference signal. A switching power stage coupled to the comparator is configured to receive a second signal derived from a combination of an output from the comparators and the input signal, wherein there is a non-linear relationship between the input signal and the timing of state transitions in the switching power stage for the purpose of generating an output that has been shifted in frequency relative to a frequency of the input signal, and which includes at least one sideband.
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Citations
95 Claims
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1. A modulator-amplifier configured for use in parametric sound reproduction systems for reproducing audio information in a medium, comprising:
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an input configured for receiving at least one input signal including audio information;
at least one reference signal generator configured for generating at least one reference signal;
at least one comparator coupled to the input and the reference signal generator configured for detecting a relationship between a first signal based on the at least one input signal and the at least one reference signal and generating a second signal based thereon;
at least one switching power stage coupled to the at least one comparator and configured to receive the second signal and drive art output signal including at least one sideband and audio information; and
wherein the relationship between the at least one input signal and the timing of state transitions in the switching power stage is non-linear. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 95)
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29. A modulator-amplifier, comprising:
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an input configured for receiving at least one input signal including audio information;
at least one reference signal generator configured for generating at least one reference signal;
a switch mode modulator configured to modulate the at least one reference signal, configured so that there is a non-linear relationship between the at least one input signal and state transitions of a switching output waveform; and
wherein the modulator-amplifier is operable for use in a parametric sound reproduction system for reproducing audio information in a medium, the modulator-amplifier generating an output signal that has been shifted in frequency relative to a frequency of the at least one input signal, and includes at least one sideband. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47)
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48. A system for generating an acoustic output reproducing an audio signal in an acoustic parametric array in an acoustic wave-transmitting medium, comprising:
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a) a modulator-amplifier which produces a modulated carrier wave output which comprises a carrier waveform at an ultrasonic frequency modulated so as to include a processed audio signal, the modulated carrier wave output is operable for driving a transducer to reproduce the audio signal from the acoustic parametric array;
the modulator-amplifier including an event generator for generating a timing signal based on comparison of the audio signal and a reference signal;
the modulator-amplifier further comprising a switching output stage coupled to the event generator for signaling the switching output stage, wherein timing of switching state transitions in the output stage is related to the audio signal by a non-linear function; and
b) an ultrasonic transducer coupled to the modulator-amplifier which converts the modulated carrier wave output into an ultrasonic waveform for producing an audio wave in a medium, whereby a pre-processed audio source signal is amplified and reproduced from the parametric array in the medium. - View Dependent Claims (49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66)
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67. A modulator-amplifier configured for use in parametric sound reproduction systems, comprising:
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a reference signal generator for generating a reference signal;
an event detector-signal generator comprising at least one comparator configured for comparing an input signal with the reference signal and generating a timing signal based upon detected events in the input signal;
a switching power output stage configured for modulating the reference signal based upon the timing signal, whereby signal modulation is integrated with power amplification of the signal to embody a non-linear relationship between the input signal and the timing of state transitions in the modulator-output stage. - View Dependent Claims (68, 70, 71, 72)
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69. A modulator amplifier as set forth in clam 67, wherein the reference signal is one of lower-sideband, upper-sideband or dual-sideband modulated.
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73. A modulator-amplifier, comprising:
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a carrier signal generator;
an event detector configured to generate a state change signal based upon detected events in an audio input signal, said event detector comparing the input signal to a reference signal;
a modulator-switching power output stage configured for modulating a carrier for parametric sound reproduction based upon the state change signal, and wherein the timing of switching between steady state levels in said output stage is related to the audio input signal by a non-linear function; and
wherein the switching frequency is selected from the group consisting of 2, 3, and 4 times the carrier frequency. - View Dependent Claims (74, 75, 76)
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77. An modulator/amplifier (ModAmp) comprising:
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a carrier reference generator for generating a carrier reference signal;
an event generator configured for comparing an audio input signal to the carrier reference signal, and generating event trigger signals based on said comparing;
an AM modulator configured for receiving the event trigger signals and generating double sideband modulation of the carrier signal;
an SSB modulator configured for receiving the event trigger signals and generating SSB modulation of the carrier signal; and
an output driver configured for receiving AM modulated or SSB modulated carrier signals and outputting a drive signal based thereon suitable for driving an ultrasonic transducer in a parametric sound reproduction system;
wherein event trigger signals are related to the audio input signal by a non-linear function and modulation is switch-mode modulation based on the event trigger signals. - View Dependent Claims (78, 79, 80, 81, 82, 83, 84, 85)
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86. A method for frequency shifting and amplifying an audio signal for use in a parametric loudspeaker system, including the steps of,
i) receiving at least one input audio signal, ii) creating at least one reference signal, iii) comparing the at least one input audio signal with the at least one reference signal to derive at least one compared product signal, iv) delivering the at least one compared product signal to a switching power stage wherein at least one operation is performed selected from the following: -
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performing nonlinear preprocessing with respect to the input audio signal, and,b)—
creating a non-triangle wave as the at least one reference signal; and
v) frequency shifting and amplifying the input audio signal by modulating the reference signal in the switching power stage. - View Dependent Claims (87, 88, 89, 90, 91, 92, 93, 94)
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Specification