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

2021 ◽  
Vol 150 (5) ◽  
pp. 3797-3806
Author(s):  
Jiaxin Zhong ◽  
Ray Kirby ◽  
Mahmoud Karimi ◽  
Haishan Zou
Keyword(s):  
Parametric Array

A micromachined efficient parametric array loudspeaker with a wide radiation frequency band

2015 ◽  
Vol 137 (4) ◽  
pp. 1732-1743 ◽  
Author(s):  
Yub Je ◽  
Haksue Lee ◽  
Kyounghun Been ◽  
Wonkyu Moon
Keyword(s):  
Frequency Band ◽  
Radiation Frequency ◽  
Parametric Array

Sub-array equalization technique for the parametric array loudspeaker to reduce nonlinear distortion

2021 ◽  
Vol 263 (5) ◽  
pp. 1497-1504
Author(s):  
Chi Zhang ◽  
Jing Ren ◽  
Chuang Shi
Keyword(s):  
Nonlinear Distortion ◽  
Ultrasonic Transducer ◽  
Previous Method ◽  
Ultrasonic Transducers ◽  
Acoustic Effect ◽  
The Past ◽  
Comparison Results ◽  
Equalization Technique ◽  
Nonlinear Acoustic ◽  
Parametric Array

The parametric array loudspeaker (PAL) is a directional loudspeaker which uses the nonlinear acoustic effect, namely the parametric array, to produce an audio beam from narrow ultrasonic beams. The PAL can efficiently deliver audible information, without generating noise to the surroundings. One significant drawback of the PAL is the nonlinear distortion. Therefore, many sophisticated methods have been proposed to preprocess the input signal of the PAL. However, those methods usually request a flat frequency response of the ultrasonic transducer array (UTA). In the past, equalization has been tried out for the whole UTA, but the performance was sometimes not satisfactory due to the inconsistent productions of ultrasonic transducers. This paper proposes to group the ultrasonic transducers by their impedances. Several sub-arrays are thereafter formed and equalized individually. The comparison results demonstrate that the propose sub-array equalization technique can suppress the nonlinear distortion of the PAL more effectively than the previous method.

Synthesis of arbitrary broadband signals for a parametric array

1982 ◽  
Vol 72 (1) ◽  
pp. 238-244 ◽  
Author(s):  
Sharad Singhal ◽  
John G. Zornig
Keyword(s):  
Parametric Array

Time domain study of the terminated transient parametric array

1983 ◽  
Vol 73 (6) ◽  
pp. 1972-1978 ◽  
Author(s):  
Nicholas G. Pace ◽  
Robert V. Ceen
Keyword(s):  
Time Domain ◽  
Parametric Array

WIDEBAND BACKSCATTERING MEASUREMENTS USING A PARAMETRIC ARRAY

1987 ◽  
pp. 265-270 ◽  
Author(s):  
V.F. Humphrey ◽  
C. Murphy ◽  
A.H.A. Moustafa
Keyword(s):  
Parametric Array

Covert Underwater Acoustic Communication System Using Parametric Array

2019 ◽  
Vol 53 (1) ◽  
pp. 20-26 ◽  
Author(s):  
Anbang Zhao ◽  
Yue Cheng ◽  
Tiansi An ◽  
Juan Hui
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Low Frequency ◽  
Nonlinear Behavior ◽  
Beam Width ◽  
Point Of View ◽  
Underwater Acoustic Communication ◽  
Water Tank ◽  
Narrow Beam ◽  
Underwater Acoustic ◽  
Parametric Array

AbstractA novel and efficient covert underwater acoustic (UWA) communication scheme using an acoustic parametric array and orthogonal frequency division multiplexing (OFDM) system is presented. The proposed system is robust and can easily be implemented in the ocean environment. The system is also very useful in military applications where the secrecy of transmission signal and location of the transmitter are extremely important. The paper exploits the difference frequency generated by the acoustic parametric array due to the nonlinear behavior of an underwater medium. Besides the lightness and compactness, the parametric array also possesses the advantage of being low-frequency, broadband, highly directive, and narrow beam with no side lobes. The narrow beam width also helps to secure the data from a spatial point of view. Experiments have been performed in a water tank, and the results are presented to show the effectiveness of the proposed scheme.

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