One article to understand the main points of ultrasonic transducer electrical parameter testing

The ultrasound industry is closely related to the electronics industry, and the quality of its core device transducer directly determines the performance of ultrasound products. The frequency of the transducer is high, and how to accurately test the power and efficiency of the transducer has always been a difficult point in the industry. This article will provide you with high-quality solutions.

1. Ultrasonic transducer

Ultrasonic transducer is a device that converts electromagnetic energy into mechanical energy (sound energy). It is widely used in many industries such as medical treatment, flaw detection, ocean exploration and so on. In ultrasonic diagnosis, firstly, the ultrasonic wave must be transmitted to the measured object, and then the reflected echo of the measured object information must be received. It is the ultrasonic transducer that plays the role of information conversion, which completes a kind of electrical-acoustic and acoustic-electrical conversion. The performance of the transducer is directly related to the performance of the ultrasonic equipment.

The power and electroacoustic efficiency of an ultrasonic transducer are important indicators to measure its performance. The common working frequencies are: 15KHz, 20KHz, 28KHz, 35KHz, 40KHz, 55KHz, 70KHz, etc. High-frequency power testing has always troubled the electronics industry difficulty.

2. High frequency power test

Ultrasonic transducer high-frequency power test first needs a high-bandwidth, high-precision power test instrument. PA8000 power analyzer, the accuracy is up to 0.01%, the bandwidth is up to 5MHz, and the amplitude-frequency response automatic compensation technology is adopted, which can significantly improve the amplitude-frequency response curve in the entire measurement frequency range, even when measuring high-frequency signals. Can ensure high-precision measurement. It is suitable for most ultrasonic transducer device testing.

One article to understand the main points of ultrasonic transducer electrical parameter testing

Figure 1 Schematic diagram of PA8000 amplitude-frequency response curve

3. Transient maximum power analysis

For ultrasound equipment, especially medical ultrasound products, the target is generally non-homogeneous media such as skin organs. Hardness, density, etc. are not the same, so the power is dynamically changing. This requires the update rate of the test equipment to be as fast as possible to analyze the transient power change curve. Only in this way can the maximum working power of the ultrasonic instrument be accurately evaluated.

PA8000 adopts large-scale data processing technology, the fastest data update rate can reach 1ms, and the transient power curve drawn by 1000 power points per second can accurately evaluate the power change characteristics of the measured object.

One article to understand the main points of ultrasonic transducer electrical parameter testing

Figure 2 Comparison of 1ms update rate and 10ms update rate

Fourth, high-frequency phase compensation

For high-frequency signals of tens of kHz such as ultrasonic transducers, the delay has a great influence on the efficiency. In actual testing, a delay of ns may cause an efficiency error of 1%. This requires the test instrument to have a delay correction function to correct the delay introduced by the instrument itself and when using an external sensor.

PA8000 power analyzer supports delay correction function, you can manually input the delay data into the instrument for correction to ensure the accuracy of high-frequency testing. It also provides sensor phase calibration services. ZLG Zhiyuan Electronics has cooperated with domestic testing institutions for many years, is familiar with the complete calibration process, and can provide a complete high-frequency test program.

One article to understand the main points of ultrasonic transducer electrical parameter testing

Figure 3 Screenshot of the delayed calibration report

With the wide application of ultrasonic technology, SiC, GaN and other new materials, the demand for high-frequency testing is increasing. However, the research on high-frequency signals requires very high test equipment. ZHIYUAN Electronics’ PA8000 power analyzer, oscilloscope recorder and other products have accumulated deep accumulation and many successful cases in the field of high-frequency testing, helping the innovation and breakthrough of power electronics technology.

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