Application Cases

【Overview】
In this study, the Aigtek ATA-1372A broadband power amplifier was used to build an experimental system for d24 piezoelectric patch research. A method for selecting excitation parameters based on dispersion characteristics was proposed to achieve single-mode SH(0,1) wave excitation using face-shear (d24) piezoelectric ceramic wafers. First, the Floquet periodic boundary condition method was employed to analyze the dispersion of SH waves in a narrow plate waveguide. The dispersion curves of the narrow plate waveguide were compared with those of an infinite wide plate to evaluate the differences between them. The results showed that in a narrow plate waveguide, the cutoff frequency of SH waves decreases with increasing plate width but is independent of plate thickness. This is completely different from the cutoff frequency variation with plate thickness observed in an infinite wide plate.

Experiment Name: Excitation of a Single SH(0,1) Mode in a Finite-Width Plate Using a d24-Type Piezoelectric Patch

Research Direction: Ultrasonic Guided Waves

Experimental Content:
This study focuses on the propagation characteristics of Shear Horizontal (SH) guided waves in a narrow plate waveguide (NPW), specifically addressing the issue of pure excitation of the SH(0,1) mode. By designing a d24-type PZT transducer, the influence of its length (Lp) on the excitation efficiency of the SH(0,1) mode was explored. Combining simulations and experiments, the feasibility of this approach for applications such as high-temperature wall thickness monitoring was evaluated.

Testing Equipment:
Aigtek ATA-1372A power amplifier; arbitrary waveform generator; transducer; sensors and data acquisition equipment, etc.

Experimental Procedure:

Figure: Schematic Diagram of the Experimental Test System

Figure: Physical Setup of the Experimental Test System

1. Signal generation and amplification: A Hanning window-modulated three-cycle 640 kHz sine wave was generated by an HS5 and amplified to a peak-to-peak voltage of 40 V by the Aigtek ATA-1372A power amplifier to drive the d24 PZT transducer.

2. Signal excitation and reception: The transducer excited SH(0,1) mode guided waves, which propagated through the NPW to the receiving sensor.

3. Data acquisition and analysis: The received signals were acquired by the HS5 and imported into a terminal for spectrum analysis, arrival time extraction, and SNR calculation.

4. Variable control experiment: Transducers with different lengths Lp (6, 12, 18, 24, 30, 36 mm) were used, and the experiment was repeated to evaluate their impact on excitation efficiency.

Experimental Results:

Figure: Experimental Results

1. All d24 PZT transducers successfully excited the SH(0,1) mode guided waves.

2. When Lp ranged from 18 mm to 24 mm, the amplitude and signal-to-noise ratio (SNR) of the received signals reached their peak values.

3. The trend of the experimental curve of SNR variation with Lp was highly consistent with the simulation results, verifying the reliability of the simulation analysis.

Advantages of Aigtek Amplifiers in This Application:

1. Wide bandwidth and high-frequency response – Precisely covers the operating frequency, ensuring undistorted amplification of the pulse signal.

2. Low distortion and high linearity – Ensures pure excitation of a single mode, avoiding interference from spurious modes.

3. Stable output and finely adjustable gain – Supports repeated experiments with different Lp transducers, ensuring data comparability.

Recommended Product: ATA-1372A Broadband Power Amplifier

Figure: ATA-1372A Broadband Amplifier Specifications and Parameters