Abstract
Recently developed analytical techniques for the measurement of microwave antennas at reduced distances are “translated” into corresponding techniques for the measurement of electroacoustic transducers in fluids. The basic theory is formulated in scattering-matrix form and emphasizes the use of plane-wave spectra for the representation of sound fields. This theory, in contrast to those based on asymptotic description of transducer characteristics, is suitable for the formulation and solution of problems involving interactions at arbitrary distances. Two new techniques (in particular) are described: One, utilizing deconvolution of transverse scanning data, which may be taken at distances d much less than the Rayleigh distance dR(≡ a2/2λ), provides a means of obtaining complete effective directivity functions, corrected for the effects of the measuring transducer. Applicability of a (two-dimensional, spatial) sampling theorem and the “fast Fourier transform” algorithm, which greatly facilitate the necessary computations, is shown. The second technique provides a means of extrapolating received signal as a function of distance (observed with d∼dR or d≫a instead of the conventional d∼dR) to obtain on-axis values of effective directivity. Other possible applications are indicated. In these techniques, pressure data are rigorously sufficient; normal velocity data are not required.
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
