Next Article in Journal
3D FEM Analysis of High-Frequency AlN-Based PMUT Arrays on Cavity SOI
Next Article in Special Issue
Wide Bandwidth Class-S Power Amplifiers for Ultrasonic Devices
Previous Article in Journal
Wearables and the Quantified Self: Systematic Benchmarking of Physiological Sensors
Previous Article in Special Issue
Design and Analysis of a Magnetically Coupled Multi-Frequency Hybrid Energy Harvester
Open AccessArticle

A Critical Step to Using a Parametric Array Loudspeaker in Mobile Devices

Department of Mechanical Engineering, POSTECH, Pohang 37673, Korea
Department of Electrical Engineering, Pukyoung National University, Busan 48513, Korea
Department of Ocean System Engineering, Jeju National University, Jeju 63243, Korea
Author to whom correspondence should be addressed.
Sensors 2019, 19(20), 4449;
Received: 22 August 2019 / Revised: 8 October 2019 / Accepted: 10 October 2019 / Published: 14 October 2019
(This article belongs to the Special Issue Piezoelectric Transducers)
A parametric array (PA) loudspeaker is a highly directional audio source that might grant one's convenience if it is used with mobile devices. However, conventional PA loudspeakers is almost impossible to apply in mobile devices using a battery because of the large power consumption and large device size. In this study, a PA loudspeaker system (PALS) was fabricated and evaluated to show that those difficulties could be overcome to apply it to mobile devices. In order to construct a PALS for demonstration, a power amplifier and signal-processing unit should also be properly designed and built. The PA source transducer should also be designed and built for a mobile device application. These components were integrated into a single PALS. The PALS generated a 125-dB primary wave and 62 dB of a different frequency wave (DFW) through the PA at 0.45 m in a 3 m × 3 m × 2 m semi-anechoic chamber. We confirmed that the half-power bandwidth (HPBW) formed a 6° beam at 83 kHz of DFW and 90 kHz of the primary wave (PW), and the HPBW formed a 7.3° beam at 5 kHz of DFW and a 7.1° beam at 10 kHz of DFW, respectively. Lastly, the power required was 6.65 W without a matching circuit, and 3.25 W with such a circuit. View Full-Text
Keywords: parametric array; directional speaker; piezoelectric micro-machined ultrasonic transducer parametric array; directional speaker; piezoelectric micro-machined ultrasonic transducer
Show Figures

Figure 1

MDPI and ACS Style

Ahn, H.; Been, K.; Kim, I.-D.; Lee, C.H.; Moon, W. A Critical Step to Using a Parametric Array Loudspeaker in Mobile Devices. Sensors 2019, 19, 4449.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

Search more from Scilit
Back to TopTop