Application Cases

【Overview】
In this study, the Aigtek ATA-L6 underwater acoustic power amplifier was used to build an experimental system for a dual-drive DC magnetic sensor based on the inverse magnetoelectric coupling effect. In this design, the magnetic field to be measured induces periodic magnetic flux changes in the two magnetoelectric coupling structures, which are then detected by pickup coils to generate measurement outputs. The dual-drive structure significantly enhances signal strength, enabling accurate magnetic field measurement without altering the external magnetic field distribution. By adjusting the drive voltage, the sensor sensitivity can be linearly tuned, thereby suppressing nonlinear errors. Furthermore, the ability of the sensor to determine the direction of the magnetic field was verified by analyzing the phase-frequency characteristics of the output signal.

Experiment Name: Design and Performance Testing of a Dual-Drive DC Magnetic Sensor Based on the Inverse Magnetoelectric Coupling Effect

Research Direction: Low-cost, high-sensitivity magnetic sensors for applications in geomagnetic navigation, biomedical detection, and industrial automation.

Experimental Content:
The sensor utilizes the inverse magnetoelectric effect, where two magnetoelectric composite structures (Metglas-PZT8) convert a DC magnetic field into an AC magnetic signal, which is then detected by a coil output. The dual-drive design doubles the signal strength without interfering with the measured magnetic field. The direction of the magnetic field is identified through a 180° phase  flip.

Testing Equipment:
ATA-L6 underwater acoustic power amplifier, signal generator, lock-in amplifier, etc.

Experimental Procedure:
The experiment used the Aigtek ATA-L6 underwater acoustic power amplifier to drive the dual magnetoelectric composite structures (Metglas-PZT8). First, a 20–80 kHz frequency sweep signal generated by a signal generator was amplified by the power amplifier to a drive voltage of 15 Vpk, exciting vibrations in the piezoelectric layer and coupling them to the magnetostrictive layer, converting the DC magnetic field into an AC magnetic signal. Subsequently, a lock-in amplifier (SR830) was used to extract the output voltage of the pickup coil, and phase analysis was simultaneously performed to identify the magnetic field direction. Finally, the sensor's response to stepwise DC magnetic fields (1 nT–300 μT) was tested in an electromagnetic shielding room, and the intensity and angle of the geomagnetic field in Xi'an were measured on-site.

Figure: Schematic Diagram of the Experimental Test System

Experimental Results:

Figure: Experimental Results

After enabling the power amplifier, the sensor performance was significantly improved:

• Sensitivity reached 10.51 mV/μT (a 105% improvement over single-structure designs), enabling the detection of weak magnetic fields at the 1 nT level.

• The dual-drive design doubled the signal strength (output of 22.93 mV) and achieved precise determination of the magnetic field direction through a 180° phase flip (error < 2°).

• The horizontal component of the geomagnetic field in Xi'an was measured to be 31.07 μT, with an angular resolution of ±5° and power consumption of only 500 mW.

Key breakthrough: The high-voltage drive capability and low-noise characteristics (<9.7 μV) of the Aigtek amplifier were critical to achieving this ultra-high sensitivity.

Advantages of Aigtek Amplifiers in This Application:

1. Ultra-low output noise – A core prerequisite for achieving weak magnetic field detection.

2. Wide bandwidth and flat frequency response – Supports frequency sweep excitation, optimizing magnetoelectric coupling efficiency.

3. High-precision voltage output and low phase distortion – Ensures accuracy in direction identification.

Recommended Product: ATA-L Series Underwater Acoustic Power Amplifier

Figure: ATA-L Series Underwater Acoustic Power Amplifier Specifications and Parameters