Modeling of Parametric Loudspeakers by Gaussian-Beam Expansion Technique

Ye, Chao; Wu, Ming; Wu, Shuaibin; Huang, Chenxi; Jiang, Yang

doi:10.1143/jjap.49.07he18

Cited by 6 publications

(5 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The paraxial model has been widely used and this assumes paraxial approximations for both the audio and ultrasound beams, so that a Gaussian beam expansion (GBE) can be used to simplify the integral into a summation of the contribution from a set of Gaussian sources. 17,20,21 The prediction accuracy of the paraxial model is the same as that of the well-known Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation, but the results are accurate only inside the paraxial region. 17,22 Furthermore, the prediction of the paraxial model is also known to be inaccurate at low frequencies.…”

Section: Introductionmentioning

confidence: 63%

See 1 more Smart Citation

A cylindrical expansion of the audio sound for a steerable parametric array loudspeaker

Zhong

Kirby

Karimi

et al. 2021

The Journal of the Acoustical Society of America

View full text Add to dashboard Cite

In this work, a cylindrical expansion for the audio sound generated by a steerable baffled parametric array loudspeaker (PAL) based on the phased array technique is derived from the Westervelt equation. The expansion is a series of twofold summations with uncoupled angular and radial components in the cylindrical coordinate system. The angular component is determined by the trigonometric functions, and the radial component is an integral containing the Bessel functions and an arbitrary excitation velocity profile. The numerical results for a typical steerable PAL are presented and compared to those obtained using the convolution model. It is found that the prediction of the audio sound using the proposed cylindrical expansion improves the agreement with the experimental results when compared to the existing models. This is because no further approximations are required in the cylindrical expansion of the quasilinear solution of the Westervelt equation, whereas the complex near field nonlinear interactions between the ultrasonic waves cannot be correctly captured in a convolution model. The proposed cylindrical expansion does, therefore, provide an alternative approach to modeling a phased array PAL and high accuracy with a relatively low computational cost.

show abstract

Section: Introductionmentioning

confidence: 63%

“…In addition, the proposed cylindrical expansion in Eqs. (19) and (20) can predict the near audio sound field as shown in Sec. IV, whereas it is not applicable for the convolution model in Eq.…”

Section: Discussionmentioning

confidence: 98%

A cylindrical expansion of the audio sound for a steerable parametric array loudspeaker

Zhong

Kirby

Karimi

et al. 2021

The Journal of the Acoustical Society of America

View full text Add to dashboard Cite

show abstract

“…It is known that not only the fundamental sound but also the second harmonic sound occurs. [23][24][25][26][27][28][29] On the basic of the principle the parametric loudspeakers produce secondary nonlinear components, we propose an efficient subcarrier arrangement for OFDM communication using parametric loudspeakers that do not cause inter-carrier interference (ICI) even if the secondary nonlinear component occurs. Specifically, we consider two subcarrier arrangement designs: odd-comb OFDM and narrow-band OFDM.…”

Section: Introductionmentioning

confidence: 99%

An efficient subcarrier arrangement for airborne OFDM communication using parametric loudspeaker

Tajima

Wakatsuki

Ebihara

et al. 2021

Jpn. J. Appl. Phys.

View full text Add to dashboard Cite

Acoustic communication in air has attracted attention as an alternative near-field communication medium. A parametric loudspeaker has the potential to achieve acoustic communication within a personal area. However, secondary nonlinear components of communication signals generated by self-demodulation in air become barriers to acoustic communication. Although the use of orthogonal frequency division multiplexing (OFDM) would be desirable, since it achieves low-calculation-cost equalization at the receiver even in a multipath fading environment, inter-carrier interference (ICI) with secondary components degrades communication quality. In this paper, we propose an efficient subcarrier arrangement for OFDM communication using parametric loudspeakers. We consider two subcarrier arrangements: odd-comb OFDM and narrow-band OFMD. The former has an active subcarrier at odd indexes, and the latter has a restricted frequency band to avoid ICI. We also test the proposed schemes in experiments. The experimental results suggest that the proposed OFDM successfully improves communication quality compared to the original OFDM.

show abstract

“…In the field of C-mode imaging, the author's group has previously presented a system for measuring and imaging B=A in a small biological sample based on the finite amplitude method 17) that uses a focused Gaussian beam. 18,19) However, since the principle of the measurement assumes uniform samples, 20,21) a nonuniform density and sound speed contradict the theory and thereby the result is not fully reliable. By analyzing the nonlinear propagation of a focused Gaussian beam transmitting through a layer of nonuniform sound speed, the uncertainty of the measured value is investigated in this study.…”

Section: Introductionmentioning

confidence: 99%

Second Harmonic Component in Focused Gaussian Beam Propagating through Nonuniform Sound-Speed Layer

Saito¹

2012

Jpn. J. Appl. Phys.

View full text Add to dashboard Cite

The fundamental and second harmonic components in a focused sound transmitting through a layer of an inhomogeneous medium with a nonuniform sound speed are analyzed. The nonlinear wave equation including the perturbation of the sound speed is solved with a successive approximation. The influence of the nonuniformity on the measurement of the acoustic nonlinearity parameter B/A in biological samples inserted in the focal region is also investigated. The axial sound-speed variation causes the relative uncertainty of the measured B/A to be the same as the rate of the sound speed within the sample. On the other hand, since the sound beam is refracted owing to the lateral variation of the sound speed, the second harmonic amplitude of the sound detected with the receiver noticeably decreases. Thus, the B/A is underestimated by half the rate of change of the sound speed within a lateral range equivalent to the sample thickness.

show abstract

Modeling of Parametric Loudspeakers by Gaussian-Beam Expansion Technique

Cited by 6 publications

References 9 publications

A cylindrical expansion of the audio sound for a steerable parametric array loudspeaker

A cylindrical expansion of the audio sound for a steerable parametric array loudspeaker

An efficient subcarrier arrangement for airborne OFDM communication using parametric loudspeaker

Second Harmonic Component in Focused Gaussian Beam Propagating through Nonuniform Sound-Speed Layer

Contact Info

Product

Resources

About