Topic
Acoustic interferometer
About: Acoustic interferometer is a research topic. Over the lifetime, 1493 publications have been published within this topic receiving 19355 citations.
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Papers
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TL;DR: In this paper, an approach to determine sound velocity in air by using standard drain pipes is described. And an investigation of the temperature dependency of the speed of sound is presented. But the authors do not consider the effect of temperature on sound velocities.
Abstract: The opportunity to plot oscillograms and frequency spectra with smartphones creates many options for experiments in acoustics, including several that have been described in this column.1–3 The activities presented in this paper are intended to complement these applications, and include an approach to determine sound velocity in air by using standard drain pipes4 and an outline of an investigation of the temperature dependency of the speed of sound.
37 citations
TL;DR: In this paper, a time domain signal processing based on narrow-band filtering of wide-band acoustic wave pulses and cross-corelation is described, which permits to measure both phase and group velocities as a function of frequency.
Abstract: Frequency broadband measurement of the characteristics of acoustic waves propagating in an object is disclosed. A time domain signal processing is described, based on narrow-band filtering of wide-band acoustic wave pulses and cross-corelation which permits to measure both phase and group velocities as a function of frequency.
36 citations
Patent•
02 Jan 2001
TL;DR: In this article, a first acoustic driver having a first radiating surface and a second radiating surfaces is arranged and constructed so that the first driver radiates sound waves into free air and the second driver radiating sound wave into the acoustic waveguide so that sound waves are radiated at the open end.
Abstract: An acoustic waveguide system, having source of acoustic radiation and a source of opposing acoustic radiation. An acoustic waveguide has an open end and an interior. A first acoustic driver having a first radiating surface and a second radiating surface is arranged and constructed so that the first radiating surface radiates sound waves into free air and the second radiating surface radiates sound waves into the acoustic waveguide so that sound waves are radiated at the open end. A source of opposing sound waves in the acoustic waveguide opposes a predetermined spectral component of the sound waves radiated into the acoustic waveguide to reduce the acoustic radiation of the predetermined spectral component from the acoustic waveguide.
36 citations
05 Oct 2003
TL;DR: In this paper, a novel heterodyne interferometer for scanning surface-acoustic waves at high frequencies, up to 6 GHz, was proposed, which facilitates the measurement of the absolute amplitude of the surface waves without calibration.
Abstract: Phase-sensitive absolute-amplitude measurements of surface waves using heterodyne interferometry. We describe a novel heterodyne interferometer for scanning surface-acoustic waves at high frequencies, up to 6 GHz. The heterodyne operation facilitates the measurement of the absolute amplitude of the surface waves without calibration. It simultaneously also enables measuring the phase. The amplitude and phase information allows a precise characterization of the surface acoustic waves. Moreover, the wave motion can be visualized in the form of animations to gain insight. The interferometer has been tested by measuring a 167 MHz SPUDT device and a 374 MHz fan-shaped SAW filter.
35 citations
Patent•
01 Nov 2006TL;DR: A bulk acoustic resonator has an acoustic reflector portion formed on a substrate and including one or more low acoustic impedance layers and one high acoustic impedance layer having a higher acoustic impedance than the low impedance layer which are disposed in stacked relation and having a piezoelectric film.
Abstract: A bulk acoustic resonator has an acoustic reflector portion formed on a substrate and including one or more low acoustic impedance layers and one or more high acoustic impedance layers having a higher acoustic impedance than the low acoustic impedance layer which are disposed in stacked relation and an acoustic resonator portion formed on the acoustic reflector portion and having a piezoelectric film At least one of the low acoustic impedance layers is made of silicon
34 citations