Title :
Class D Power Amplifier for Audio Beam System
Author :
Yang, Liwei ; Xu, Limei ; Yang, Tai ; Zhang, Bo
Author_Institution :
Univ. of Electron. Sci. & Technol. of China, Chengdu
Abstract :
Audio Beam is a revolutionary way of projecting audio signal in a highly directional manner to the listener. A high efficiency class D power amplifier is presented to drive the piezoelectric load, polyvinylidene fluoride(PVDF) ultrasonic transducer of Audio Beam, between 20 kHz and 60 kHz. The class D amplifier is composed of power MOSFETS, type IRFU2407, in a full H-Bridge configuration driven by HIPxxxxA circuits in bootstrap mode. The specific nature of the problem comes from the fact that the transducer loaded is mostly capacitive around the resonant frequency. The insertion of two appropriate inductors in front of the load introduced an efficient solution to the problem due to the reactance matching and resonance. In the end, the experiment of the realized system testified that the class-D amplifier designed is able to drive the ultrasonic transducer with extreme high efficiency and high power.
Keywords :
power amplifiers; ultrasonic transducers; audio beam system; capacitive load; polyvinylidene fluoride; power amplifier; reactance matching; resonant frequency; ultrasonic transducer; Circuits; High power amplifiers; Inductors; MOSFETs; Piezoelectric transducers; Power amplifiers; Resonance; Resonant frequency; System testing; Ultrasonic transducers; amplifier for capacitive load; audio beam; class D amplifier;
Conference_Titel :
Mechatronics and Automation, 2007. ICMA 2007. International Conference on
Conference_Location :
Harbin
Print_ISBN :
978-1-4244-0828-3
Electronic_ISBN :
978-1-4244-0828-3
DOI :
10.1109/ICMA.2007.4304121
