Electromagnetic ultrasonic signal enhancement circuit

Abstract

The electromagnetic ultrasonic signal enhancement circuit provided by the utility model comprises an electromagnetic ultrasonic interface, a matching inductor, a basic unit and a basic unit, and the basic unit comprises a first matching capacitor, a first electromagnetic ultrasonic inductor, a first switching circuit and a second switching circuit. The basic unit comprises a second matching capacitor, a second electromagnetic ultrasonic inductor, a third switching circuit and a fourth switching circuit; the first switching circuit, the second switching circuit, the third switching circuit and the fourth switching circuit respectively comprise two diodes of which the anodes and the cathodes are connected; and the electronic components are electrically connected in sequence to form the electromagnetic ultrasonic signal enhancement circuit. According to the utility model, the series-parallel connection state of the coil is automatically switched through the conduction or cut-off of the diode, the emission current amplitude and the receiving sensitivity can be obviously improved, the cost is reduced, the response speed is improved, and the high-frequency excitation signal is better adapted.

Description

Technical Field

[0001] This utility model relates to the technical field of electromagnetic ultrasonic testing, and in particular to an electromagnetic ultrasonic signal enhancement circuit. Background Technology

[0002] Currently, the signal enhancement circuits in electromagnetic ultrasonic testing systems mainly employ the following two schemes:

[0003] (1) Single electromagnetic coil structure

[0004] In this scheme, the transmitter is directly connected to a fixed impedance matching network, and the receiver induces a signal through a coil with a fixed number of turns. However, during the transmission phase, the fixed impedance limits the transmission current, resulting in insufficient electromagnetic ultrasonic excitation energy. Furthermore, during the reception phase, the fixed equivalent number of turns of the coil results in an induced voltage of only microvolts, leading to a low signal-to-noise ratio.

[0005] (2) Multi-coil fixed series-parallel structure

[0006] This scheme switches the series and parallel states of the coils using a physical switch such as a relay, but requires additional control circuitry. However, the above scheme suffers from problems during the transmission phase, such as the slow response speed of the mechanical switch and its inability to adapt to high-frequency excitation signals. During the reception phase, noise introduced by the switch contact resistance degrades the signal quality.

[0007] Furthermore, neither of the above two solutions can improve signal strength through modular expansion, requiring a complete hardware redesign. Therefore, the signal enhancement circuitry in existing technologies still needs improvement. Utility Model Content

[0008] To address the aforementioned problems in the prior art, this invention provides an electromagnetic ultrasonic signal enhancement circuit that significantly improves the amplitude of the transmitting current and the sensitivity of the receiving signal.

[0009] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0010] In a first aspect, this utility model provides an electromagnetic ultrasonic signal enhancement circuit, including an electromagnetic ultrasonic interface, a matching inductor, a base unit, and a basic unit. The base unit includes a first matching capacitor, a first electromagnetic ultrasonic inductor, a first switching circuit, and a second switching circuit. The basic unit includes a second matching capacitor, a second electromagnetic ultrasonic inductor, a third switching circuit, and a fourth switching circuit. The first switching circuit, the second switching circuit, the third switching circuit, and the fourth switching circuit all include two diodes with their positive and negative terminals connected together.

[0011] The electromagnetic ultrasonic interface, the first switching circuit, the first electromagnetic ultrasonic inductor, and the second switching circuit are sequentially electrically connected to form a loop. The two ends of the first matching capacitor are connected in parallel to the two ends of the first switching circuit connected to the first end of the electromagnetic ultrasonic interface. The first end of the matching inductor is connected to the second end of the electromagnetic ultrasonic interface.

[0012] The first end of the second electromagnetic ultrasonic inductor is electrically connected to the first end of the third switching circuit and the first end of the second matching capacitor, and the second end is electrically connected to the first end of the fourth switching circuit and the second end of the matching inductor. The second end of the second matching capacitor is electrically connected to the second end of the fourth switching circuit. The second end of the third switching circuit and the second end of the fourth switching circuit are respectively connected to the two ends of the first electromagnetic ultrasonic inductor.

[0013] The beneficial effects of this invention are as follows: By automatically switching the series and parallel states of the coils through diode conduction or cutoff, when transmitting ultrasonic waves, a high-frequency high-voltage pulse is input to the electromagnetic ultrasonic interface, the diode conducts, and the first and second electromagnetic ultrasonic inductors are connected in parallel, reducing the total impedance and significantly increasing the excitation current. When receiving ultrasonic waves, the electromagnetic ultrasonic interface receives a microvolt voltage, the diode cuts off, and the signal forms a series path through capacitive coupling, increasing the equivalent number of turns of the coil. The received ultrasonic signals are linearly superimposed, significantly increasing the induced voltage and the signal-to-noise ratio, thus significantly improving the amplitude of the transmitting current and the receiving sensitivity. Simultaneously, the automatic diode switching eliminates the need for mechanical switches and control circuits, as well as control signals, reducing costs and improving response speed, making it more suitable for high-frequency excitation signals.

[0014] Optionally, there are two or more basic units. The first basic unit is electrically connected to the basic unit. The second end of the third switching circuit and the second end of the fourth switching circuit in the second basic unit are connected to the two ends of the second electromagnetic ultrasonic inductor in the first basic unit.

[0015] The second end of the matching inductor is connected only to the second end of the second electromagnetic ultrasonic inductor in the last basic unit.

[0016] Optionally, the basic unit is three.

[0017] Optionally, the inductance value of the matching inductor is matched to the number of basic units connected.

[0018] Optionally, the diode is a PIN diode or a fast recovery diode.

[0019] Optionally, both the first and second electromagnetic ultrasonic inductors are electromagnetic ultrasonic coils, and multiple electromagnetic ultrasonic coils are connected by a rigid PCB or a flexible PCB, and are tightly stacked with the same winding direction. Attached Figure Description

[0020] Figure 1 This is a circuit diagram of an electromagnetic ultrasonic signal enhancement circuit according to an embodiment of the present invention.

[0021] Explanation of reference numerals in the attached figures:

[0022] H1, Electromagnetic ultrasonic interface;

[0023] Ln+1, matching inductor;

[0024] C1, first matching capacitor; C2-C4, second matching capacitors;

[0025] D1-D16, diodes;

[0026] L1, first electromagnetic ultrasonic inductor; L2-L4, second electromagnetic ultrasonic inductor. Detailed Implementation

[0027] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention can be understood more clearly and thoroughly, and that the scope of the present invention can be fully conveyed to those skilled in the art. Example 1

[0028] Please refer to Figure 1 This embodiment provides an electromagnetic ultrasonic signal enhancement circuit, including an electromagnetic ultrasonic interface H1, a matching inductor Ln+1, a basic unit, and a fundamental unit. The basic unit includes a first matching capacitor C1, a first electromagnetic ultrasonic inductor L1, a first switching circuit, and a second switching circuit. The fundamental unit includes a second matching capacitor, a second electromagnetic ultrasonic inductor, a third switching circuit, and a fourth switching circuit. Each of the first, second, third, and fourth switching circuits includes two diodes connected with their positive and negative terminals, which function to form a current path and change the series-parallel relationship of the coils under high-voltage excitation.

[0029] The electromagnetic ultrasonic interface H1, the first switching circuit, the first electromagnetic ultrasonic inductor L1, and the second switching circuit are sequentially electrically connected to form a loop. The two ends of the first matching capacitor C1 are connected in parallel to the two ends of the first switching circuit, which is connected to the first end of the electromagnetic ultrasonic interface H1. The first end of the matching inductor Ln+1 is connected to the second end of the electromagnetic ultrasonic interface H1. The first end of the second electromagnetic ultrasonic inductor is electrically connected to the first end of the third switching circuit and the first end of the second matching capacitor, and its second end is electrically connected to the first end of the fourth switching circuit and the second end of the matching inductor Ln+1. The second end of the second matching capacitor is electrically connected to the second end of the fourth switching circuit. The second ends of the third and fourth switching circuits are respectively connected to the two ends of the first electromagnetic ultrasonic inductor L1.

[0030] like Figure 1 As shown, this embodiment has three basic units. In other embodiments, there are two or more basic units, such as two, four, or even more. In other words, this embodiment can be expanded by increasing the number of basic units to adapt to different detection needs.

[0031] Specifically, the first basic unit is electrically connected to the foundation unit, and the second terminals of the third and fourth switching circuits in the subsequent basic unit are connected to the two ends of the second electromagnetic ultrasonic inductor in the preceding basic unit. For example... Figure 1 As shown, the second matching capacitor C2, diodes D5-D8, and the second electromagnetic ultrasonic inductor L2 form the first basic unit; the second matching capacitor C3, diodes D9-D12, and the second electromagnetic ultrasonic inductor L3 form the second basic unit; and the second matching capacitor C4, diodes D13-D16, and the second electromagnetic ultrasonic inductor L4 form the third basic unit. In the first basic unit, the second terminals of the third and fourth switching circuits are connected to the two ends of the first electromagnetic ultrasonic inductor L1 in the basic unit. In the second basic unit, the second terminals of the third and fourth switching circuits are connected to the two ends of the second electromagnetic ultrasonic inductor L2 in the first basic unit. In the third basic unit, the second terminals of the third and fourth switching circuits are connected to the two ends of the second electromagnetic ultrasonic inductor L3 in the second basic unit.

[0032] At this point, the second terminal of the matching inductor Ln+1 is connected to the second terminal of the second electromagnetic ultrasonic inductor L4 in the third basic unit. In other words, the matching inductor Ln+1 is only connected to the second terminal of the second electromagnetic ultrasonic inductor in the last basic unit. The inductance value of the matching inductor Ln+1 is matched to the number of connected basic units; that is, as the number of connected basic units increases, this matching value changes, and the impedance transformation ratio increases proportionally to n².

[0033] In this embodiment, both the first electromagnetic ultrasonic inductor L1 and the second electromagnetic ultrasonic inductor L4 are electromagnetic ultrasonic coils. Multiple electromagnetic ultrasonic coils are connected via a rigid PCB and are tightly stacked with the same winding direction. In other embodiments, multiple electromagnetic ultrasonic coils are connected via a flexible PCB. The advantage of this method is that it can conform to curved surfaces, but the disadvantage is increased high-frequency losses.

[0034] In this embodiment, diodes D1-D16 are fast recovery diodes, which have a low forward voltage drop and high emission efficiency. In other embodiments, diodes D1-D16 can be replaced with PIN diodes, which have a shorter reverse recovery time; the disadvantage is that the forward voltage drop increases, leading to a decrease in emission efficiency.

[0035] Therefore, the working process of an electromagnetic ultrasonic signal enhancement circuit in this embodiment is as follows:

[0036] Transmission Phase: During ultrasonic wave transmission, a high-frequency high-voltage pulse is input to the electromagnetic ultrasonic interface H1; diodes D1-D16 are forward biased and conduct, forming four parallel branches: H1→D1~D4→L1, H1→D5~D8→L2, H1→D9~D12→L3, H1→D13~D16→L4; thus, the first electromagnetic ultrasonic inductor L1 and the second electromagnetic ultrasonic inductors L2-L4 are in parallel, the total impedance is reduced to 1 / 4 of that of a single coil, and the excitation current is greatly increased;

[0037] Receiving stage: When receiving ultrasound, the received signal voltage is microvolts, lower than the forward voltage of diodes D1-D16, so diodes D1-D16 are cut off; the signal forms a series path through capacitive coupling: H1→L4→C4→L3→C3→L2→C2→L1→C1→H1. The equivalent number of turns of the coil increases by 4 times, the received ultrasound signals are linearly superimposed, the induced voltage is greatly increased, and the signal-to-noise ratio is greatly improved.

[0038] Therefore, this embodiment has the following advantages:

[0039] 1. Significant performance improvement: The amplitude of the transmitting current is greatly increased, and the amplitude of the received signal is significantly increased, thus significantly improving the amplitude of the transmitting current and the receiving sensitivity.

[0040] 2. Dynamic response advantage: The diode switches automatically without control signals, and the response time is in the nanosecond range; it is more compatible with high-frequency excitation signals, and the compatibility frequency is greatly improved compared with mechanical switches.

[0041] 3. Cost and Reliability: Eliminating mechanical switches and control circuits significantly reduces costs; with no moving parts, the MTBF (Mean Time Between Failure) is greater than 100,000 hours, making it more reliable.

[0042] 4. Expandability and flexibility: The modular design supports multi-coil cascading to adapt to different detection needs.

[0043] In the description of this utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0044] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0045] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "beneath" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0046] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0047] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An electromagnetic ultrasonic signal enhancement circuit, characterized by, The electromagnetic ultrasonic interface, the first switch circuit, the first electromagnetic ultrasonic inductor and the second switch circuit are sequentially connected to form a loop, two ends of the first matching capacitor are connected in parallel to two ends of the first switch circuit connected with the first end of the electromagnetic ultrasonic interface, and the first end of the matching inductor is connected with the second end of the electromagnetic ultrasonic interface. The first end of the second electromagnetic ultrasonic inductor is electrically connected with the first end of the third switch circuit and the first end of the second matching capacitor, the second end is electrically connected with the first end of the fourth switch circuit and the second end of the matching inductor, the second end of the second matching capacitor is electrically connected with the second end of the fourth switch circuit, and the second end of the third switch circuit and the second end of the fourth switch circuit are respectively connected to two ends of the first electromagnetic ultrasonic inductor. The basic unit is provided with two or more than two, the first basic unit is electrically connected with the basic unit, the second end of the third switch circuit and the second end of the fourth switch circuit in the latter basic unit are connected to two ends of the second electromagnetic ultrasonic inductor in the former basic unit.

2. An electromagnetic ultrasonic signal enhancement circuit according to claim 1, wherein, The second end of the matching inductor is only connected to the second end of the second electromagnetic ultrasonic inductor in the last basic unit. The basic unit is three.

3. An electromagnetic ultrasonic signal enhancement circuit according to claim 2, characterised in that, The inductance value of the matching inductor matches the number of the accessed basic units.

4. An electromagnetic ultrasonic signal enhancement circuit according to claim 2, wherein, The diode is a PIN diode or a fast recovery diode.

5. An electromagnetic ultrasonic signal enhancement circuit according to any one of claims 1 to 4, characterised in that, The first electromagnetic ultrasonic inductor and the second electromagnetic ultrasonic inductor are both electromagnetic ultrasonic coils, a plurality of electromagnetic ultrasonic coils are connected through rigid PCB or flexible PCB, and are closely laminated and wound in the same direction.

6. An electromagnetic ultrasonic signal enhancement circuit according to any one of claims 2 to 4, characterised in that, ​

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