Application Cases

Experiment Name: Application of High-Voltage Amplifiers in Testing the Frequency Response Characteristics of Glass-Based Piezoelectric Thin Film Ultrasonic Transducers

Experiment Objective:
Based on the fundamental principles of piezoelectric thin film ultrasonic transducers, the basic theory of audio beamforming, and specific application scenarios, this study proposes a multilayer circular piezoelectric thin film structure suitable for the requirements of this project, in comparison with traditional piezoelectric transducer structures. Theoretical analysis of its acoustic characteristics was conducted.

Experimental Equipment:
Ultrasonic carrier wave generator, ATA-4011 high-voltage power amplifier, ultrasonic transducer, audio source, etc.

Experimental Procedure:
The test system consists of two parts: the audio beamforming loudspeaker system centered on the glass-based piezoelectric thin film transducer studied in this project, and the data acquisition system. The loudspeaker system mainly includes a signal source, high-voltage amplifier, oscilloscope, and piezoelectric thin film ultrasonic transducer. The data acquisition system consists of an ultrasonic microphone, an audible sound microphone, and a signal dynamic analyzer.

Figure: Physical Image of the Sample

The physical sample of the glass-based piezoelectric thin film ultrasonic transducer is shown in the figure. The sample test system was constructed based on the principle of audio beamforming. The audio beamforming system operates as follows: the audio signal from the audio source enters the modulator, where it is modulated onto the ultrasonic carrier wave generated by the ultrasonic generator. The modulated ultrasonic signal is then transmitted to the ultrasonic amplifier for amplification. Finally, the amplified signal serves as the driving signal for the ultrasonic transducer, which operates in the ultrasonic frequency range. The ultrasonic waves emitted by the transducer self-demodulate into audible sound in the air. The audio beamforming system mainly comprises three core components: the modulator, the high-voltage amplifier, and the transducer, as shown in the figure.

Figure: Audio Beamforming System

Experimental Results:
Compared with the simulation results, the resonance frequency is higher by 2 kHz, and the sound pressure level is lower by 3 dB. The simulation environment is based on ideal conditions, whereas the actual test environment, despite efforts to minimize ambient noise, cannot achieve the perfect conditions of the simulation. The differences between the simulation and test results fall within an acceptable margin of error.

Figure: Sample Frequency Response Curve

Figure: ATA-4011C High-Voltage Power Amplifier Specifications and Parameters