An ultrasonic probe with integrated signal excitation and amplification module

Abstract

The invention discloses an ultrasonic probe with an integrated signal excitation and amplification module, comprising a probe connector, a probe frame, a signal excitation module, a piezoelectric chip, an absorbing material and a signal amplification module, wherein the piezoelectric chip and the absorbing material are installed in the probe frame at a certain angle, the signal excitation module and the signal amplification module are installed above the piezoelectric chip, the input of the signal excitation module is connected to the input interface of the probe connector, and the output is connected to the piezoelectric chip. The beneficial effects are: integrating the ultrasonic signal excitation module and the signal amplification module; improving the equivalent signal-to-noise ratio of the probe; improving the anti-interference ability of the probe; and reducing the requirements of the ultrasonic instrument.

Description

Technical Field

[0001] The invention belongs to non-destructive ultrasonic testing, and in particular relates to an ultrasonic probe with an integrated signal excitation amplification module. Background Art

[0002] In the field of non-destructive ultrasonic testing, the ultrasonic detection probe, as an acoustic-electric transducer, is an important component in ultrasonic testing. It is responsible for inducing an ultrasonic signal on the piezoelectric chip of the probe from the excitation electrical signal emitted by the ultrasonic instrument. The sound wave signal propagates on the object being tested, is reflected back, and is converted into a weak electrical signal through the piezoelectric chip on the probe, which is returned to the ultrasonic instrument for collection and processing.

[0003] A traditional ultrasonic probe consists of the following parts: an electrical signal connector, a piezoelectric chip (divided into a transmitting chip and a receiving chip, or a hybrid chip), a wedge, an absorbing material, and a probe frame. The piezoelectric chip converts the energy signal emitted by the ultrasonic device into a sound wave signal, which is then converted back into an electrical signal after being reflected by an object and transmitted to the ultrasonic device through the connector for collection and processing.

[0004] Since the instrument and ultrasonic probe are connected by a long coaxial cable, they are easily interfered by other signals, resulting in low signal-to-noise ratio and detection sensitivity. Summary of the invention

[0005] The object of the present invention is to provide an ultrasonic probe with an integrated signal excitation and amplification module, so as to equivalently improve the signal-to-noise ratio and anti-interference capability of the ultrasonic probe.

[0006] The technical solution of the present invention is as follows: an ultrasonic probe with an integrated signal excitation and amplification module, comprising a probe connector, a probe frame, a signal excitation module, a piezoelectric chip, an absorbing material and a signal amplification module, wherein the piezoelectric chip and the absorbing material are installed in the probe frame at a certain angle, the signal excitation module and the signal amplification module are installed above the piezoelectric chip, the input of the signal excitation module is connected to the input interface of the probe connector, and the output is connected to the piezoelectric chip.

[0007] The signal excitation module and the signal amplification module are installed above the piezoelectric chip and are sealed and fixed with a glue-like material.

[0008] The signal amplification module input is connected to the piezoelectric chip.

[0009] The output of the signal amplification module is connected to the probe connector output interface.

[0010] The command signal of the instrument is received through the probe connector and transmitted to the signal excitation module.

[0011] After receiving the command signal, the signal excitation module generates a corresponding ultrasonic excitation signal, and the ultrasonic excitation signal is connected to the piezoelectric chip.

[0012] The piezoelectric chip converts the excitation signal into an ultrasonic signal, which is then transmitted out of the probe through the wedge block and propagated to the object to be inspected. The ultrasonic signal reflected back from the object to be inspected induces a weak ultrasonic signal on the piezoelectric chip, which is then amplified by the signal amplification module and transmitted to the ultrasonic instrument through the probe connector.

[0013] The beneficial effects of the present invention are: integrating an ultrasonic signal excitation module and a signal amplification module; improving the equivalent signal-to-noise ratio of the probe; improving the anti-interference ability of the probe; and reducing the requirements for the ultrasonic instrument. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of an ultrasonic probe with an integrated signal excitation and amplification module provided by the present invention.

[0015] Figure 2 This is the circuit diagram of the ultrasonic signal excitation module.

[0016] Figure 3 This is the circuit diagram of the signal amplification module.

[0017] In the figure, 1 is a probe connector, 2 is a probe frame, 3 is an ultrasonic signal excitation module, 4 is a wedge, 5 is a piezoelectric chip, 6 is an absorbing material, and 7 is a signal amplification module. DETAILED DESCRIPTION

[0018] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] The present invention is an ultrasonic probe with an integrated signal excitation amplification module. The ultrasonic instrument does not need to transmit an excitation signal, but only needs to give an excitation frequency command. The internal signal excitation module generates a corresponding excitation signal and transmits it to a piezoelectric chip. The electrical signal induced by the piezoelectric chip passes through the internal signal amplifier module to amplify the weak signal by tens of dB (20-40 dB) and transmit it to the ultrasonic instrument through a coaxial cable. This can improve the jitter of the ultrasonic excitation signal (when the excitation signal of a traditional ultrasonic probe passes through a coaxial cable, the pulse frequency is affected by the distributed parameters of the cable, which will reduce the jitter of the rising and falling edges of the pulse). Since the induced signal is amplified, the anti-interference ability during the coaxial cable transmission process can be reduced. The signal-to-noise ratio of the probe is improved. At the same time, the requirements of the ultrasonic detection system for the ultrasonic instrument are reduced.

[0020] like Figure 1As shown, an ultrasonic probe with an integrated signal excitation and amplification module of the present invention includes a probe connector 1, a probe frame 2, a signal excitation module 3, a wedge block 4, a piezoelectric chip 5, an absorbing material 6, and a signal amplification module 7.

[0021] The command signal of the instrument is transmitted to the signal excitation module 3 through the probe connector 1. After receiving the command signal, the signal excitation module 3 generates a corresponding ultrasonic excitation signal. The ultrasonic excitation signal is connected to the piezoelectric chip 5. The piezoelectric chip 5 converts the excitation signal into an ultrasonic signal. The ultrasonic signal is driven out of the probe through the wedge block 4 and propagates to the object to be inspected. The ultrasonic signal reflected back from the object to be inspected induces a weak ultrasonic signal on the piezoelectric chip 5. After passing through the signal amplification module 7, the weak ultrasonic signal is amplified and transmitted to the ultrasonic instrument through the probe connector 1.

[0022] The piezoelectric chip 5 and the absorbing material 6 are installed in the probe frame 2 at a certain angle, the signal excitation module 3 and the signal amplification module 7 are installed above the piezoelectric chip 5, and are sealed and fixed with a gelatinous material, the input of the signal excitation module 3 is connected to the input interface of the probe connector 1, and the output is connected to the piezoelectric chip 5. The input of the signal amplification module 7 is connected to the piezoelectric chip 5, and the output is connected to the output interface of the probe connector 1.

[0023] The probe connector 1 adopts a coaxial socket of the FFA.00 series of Lemo Company with an impedance of 50 ohms; it is fixed in the middle of the probe frame.

[0024] The probe frame 2 is surrounded by pine wood chips (particle diameter is less than 2 mm) solidified with transparent glue, so that the frame can isolate external sound waves and effectively reduce external noise interference.

[0025] The internal angle of the wedge block 4 is set according to the angle requirements of ultrasonic testing, and can be set to 0°, 30°, 45°, 60°, 75°, etc., with an accuracy of 1%; the flatness of the outer surface of the wedge block (the contact surface with the tested surface) is less than 0.1mm.

[0026] The thickness of the piezoelectric chip 5 varies according to the frequency of the probe. Taking a 2 MHz probe as an example, the thickness is 0.35 mm and the accuracy is 5%.

[0027] The surface of the absorbing material 6 is processed into triangular grooves with a depth of 2 mm and an angle of 60°.

[0028] The signal excitation module uses TI's TX517IZCQ, which is a dual-channel, high-voltage, fully integrated multi-level ultrasonic transmitter. Figure 2The peripheral circuit is designed in this way, which includes: clock input (200MHz), configuration input, enable input (2.5V logic level high), channel input (channelA and channelB), power input (+5V, -5V DC), and external related resistors and capacitors, so that the ultrasonic excitation signal can be output from outA and outB of TX517. A 2.3uH inductor is used between outA and outB for isolation ( Figure 2 N1 and N2) N2 output is connected to two protection diodes D1 and D2, and an external 100 ohm ( Figure 2 The accuracy of R1 is 0.1%, and the accuracy is guaranteed within -20 degrees Celsius to 80 degrees Celsius). A 100pf capacitor (accuracy is 1%, and the accuracy is guaranteed within -20 degrees Celsius to 80 degrees Celsius) is connected in parallel next to it as an output filter. In this way, the probe signal excitation module can be realized.

[0029] Since the ultrasonic chip sensing signal is very small, below millivolt (1mV=0.001V), the sensing current is also very small, below microampere (1uA=10-6A). Therefore, the signal amplification module uses TI's LPV821 operational amplifier with extremely low offset voltage (less than 10uV), extremely low zero drift (less than 0.096uV / .C, 1uV=10-6V), and extremely low input bias current (less than 7pA=10-12A). The design circuit is as follows Figure 3 As shown. The ultrasonic sensing signal is input from the + and - ends, Vbias is 0V, Vcc is 3.3V, and the precision resistors are R1, R2, R3, and R4. The resistance values ​​satisfy the following relationship: R4 / / R3=R2 / / R1 ( / / is parallel connection). Its accuracy is (0.1%). Take R3=R1=1.000K ohms, R2=R4=100.0K ohms, and the magnification is The amplification ratio is 40dB. Vout is the voltage after amplification, and Vin is the voltage before amplification. This realizes the function of pre-signal amplification inside the probe.

Claims

1. An ultrasonic probe with an integrated signal excitation and amplification module, characterized in that: It includes a probe connector, a probe frame, a signal excitation module, a piezoelectric chip, an absorbing material and a signal amplification module. The piezoelectric chip and the absorbing material are installed in the probe frame at a certain angle. The signal excitation module and the signal amplification module are installed above the piezoelectric chip. The input of the signal excitation module is connected to the input interface of the probe connector, and the output is connected to the piezoelectric chip. The signal excitation module and the signal amplification module are installed above the piezoelectric chip and sealed and fixed with a glue-like material; The input end of the signal amplification module is connected to the piezoelectric chip; The output end of the signal amplification module is connected to the input interface of the probe connector; Receive the command signal of the instrument through the probe connector and transmit it to the signal excitation module; After receiving the command signal, the signal excitation module generates a corresponding ultrasonic excitation signal, and the ultrasonic excitation signal is connected to the piezoelectric chip; The piezoelectric chip converts the excitation signal into an ultrasonic signal, which is then transmitted out of the probe through the wedge block and propagated to the object to be inspected. The ultrasonic signal reflected back from the object to be inspected induces a weak electrical signal on the piezoelectric chip, which is then amplified by the signal amplification module and transmitted to the ultrasonic instrument through the probe connector.

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