Square wave generation device based on semiconductor switch

Abstract

The application provides a square wave generating device based on a semiconductor switch, which comprises a power supply, a charging resistor, a coaxial cable, a semiconductor coaxial switch, a load and a control module, the power supply is connected with the coaxial cable through the charging resistor, the coaxial cable comprises a plurality of coaxial transmission lines, the coaxial transmission lines are connected through coaxial reed relay switches, the coaxial cable is connected with the load through the semiconductor coaxial switch, and the control module is electrically connected with the coaxial reed relay switches and the semiconductor coaxial switch respectively. The square wave generating device based on the semiconductor switch is used for controlling the length of the coaxial cable to control the width of the square wave, so that the square wave pulse width adjustment is more convenient, efficient and accurate. The semiconductor coaxial switch is arranged to improve the output performance of the square wave pulse and meet the demand of the electromagnetic compatibility field for high-speed and high-voltage signals. The structure of the semiconductor coaxial switch is optimized, electromagnetic interference is effectively blocked, and the stability of the semiconductor coaxial switch is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electromagnetic compatibility test, and in particular to a square wave generating device based on semiconductor switch. BACKGROUND

[0002] High-frequency noise related test usually requires specific square wave pulse signals. With the rapid development of electronic technology, the performance requirements for square wave pulse signals are increasingly stringent, not only requiring higher voltage amplitude, but also requiring extremely fast rise time and flexible pulse width.

[0003] At present, the main switch in the traditional square wave generating device usually adopts a high-voltage and large-current mercury type wet reed switch tube or a gas switch. The high-voltage and large-current mercury type wet reed switch tube has the following defects: first, since mercury is not environmentally friendly, it has almost stopped production; second, the high-voltage and large-current type wet reed tube is difficult to adapt to applications above 80Hz, and the switching frequency is limited; third, it cannot avoid contact jitter, which will lead to incomplete controllability of the output, seriously affecting the stability and accuracy of the test. The gas switch is difficult to control, resulting in poor output stability, and the gas switch is usually applied in the super high voltage field. In the voltage range required by the conventional electromagnetic compatibility high-frequency noise test, its advantages are difficult to play, and the service life of the gas switch is short, which is not conducive to long-term stable use.

[0004] The existing square wave generating device has complex operation and insufficient flexibility in pulse width adjustment. Generally, the pulse width is changed by manually adjusting the coaxial line length or replacing the transmission line, which is tedious and time-consuming, and cannot adapt to diversified needs. SUMMARY

[0005] The purpose of the present application is to provide a square wave generating device based on semiconductor switch, which can solve one or more of the above technical problems.

[0006] According to one aspect of the present application, a square wave generating device based on semiconductor switch is provided, comprising: a power supply, a charging resistor, a coaxial cable, a semiconductor coaxial switch, a load and a control module, the power supply is connected with the coaxial cable through the charging resistor, the coaxial cable comprises a plurality of coaxial transmission lines, and the coaxial transmission lines are connected through coaxial reed relay switches; the coaxial cable is connected with the load through the semiconductor coaxial switch, the semiconductor coaxial switch comprises a plurality of switch tubes, the switch tubes are connected in series, and the control module is electrically connected with the coaxial reed relay switch and the semiconductor coaxial switch respectively, and the control module is used for controlling the on-off of the coaxial reed relay switch and the semiconductor coaxial switch.

[0007] In some embodiments, the lengths of the coaxial transmission lines are completely the same or not completely the same.

[0008] In some embodiments, the coaxial reed relay switch includes: a housing, a reed switch disposed within the housing, and a first insulating layer and a second insulating layer disposed between the housing and the reed switch; the first insulating layer is disposed between the reed switch and the second insulating layer, and the second insulating layer is disposed between the first insulating layer and the housing.

[0009] In some implementations, several switching transistors in a semiconductor coaxial switch are connected in series in a line.

[0010] In some embodiments, the semiconductor coaxial switch includes a shielding shell, a third insulating layer, a fourth insulating layer, and a semiconductor switch array. The semiconductor switch array includes a plurality of switches connected in series. A copper rod is connected to the input terminal of the semiconductor switch array. The third insulating layer is disposed between the semiconductor switch array and the fourth insulating layer, and the fourth insulating layer is disposed between the third insulating layer and the shielding shell.

[0011] In some embodiments, both the input and output terminals of the semiconductor coaxial switch are provided with SHV high-voltage coaxial connectors; or the input or output terminal of the semiconductor coaxial switch is provided with an SHV high-voltage coaxial connector.

[0012] In some implementations, the fourth insulating layer is made of polytetrafluoroethylene (PTFE) insulating material.

[0013] In some implementations, the third insulating layer is made of thermally conductive silicone.

[0014] In some implementations, the shielding shell is made of brass, and the inner surface of the shielding shell is plated with nickel.

[0015] In some implementations, the control module is electrically connected to a semiconductor coaxial switch via a semiconductor switch driver module.

[0016] The square wave generation device based on semiconductor switches provided by this invention has the following beneficial effects:

[0017] (1) A coaxial reed relay switch is set between coaxial transmission lines. The on and off of the coaxial reed relay switch is controlled by the control module, thereby controlling the length of the coaxial cable. The width of the square wave is determined by the length of the coaxial cable, so that the width of the square wave is not affected by the driving pulse width. The adjustment of the square wave pulse width is more convenient, efficient and accurate, solving the problems of inconvenient adjustment of traditional equipment and difficulty in transmitting the extremely narrow driving pulse width to the high potential gate.

[0018] (2) A semiconductor coaxial switch is set up to improve the output performance of square wave pulse, while meeting the two requirements of high voltage and fast rise time. This satisfies the electromagnetic compatibility field's requirements for high-speed and high-voltage signals, makes up for the shortcomings of traditional mercury wet reed switch tubes in terms of environmental protection, frequency and controllability, and makes up for the defects of gas switches that are difficult to control under normal voltage.

[0019] (3) Optimize the structure of the semiconductor coaxial switch, set the shielding shell as the outer shielding layer, and the copper rod connected to the input end of the semiconductor switch array as the inner conductor. The shielding shell of the semiconductor coaxial switch and the copper rod form a coaxial shielding space, which wraps the core components such as the semiconductor switch array, effectively blocking electromagnetic interference, improving the stability of the semiconductor coaxial switch, reducing signal reflection, and solving the problem that the existing semiconductor switch is easily affected by electromagnetic interference and affects the waveform quality.

[0020] In addition, unless otherwise specified, all aspects of the technical solution of this invention can be implemented by conventional means in the field. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of a square wave generation device based on a semiconductor switch provided in an embodiment of the present invention.

[0023] Figure 2 This is a schematic diagram of a coaxial reed relay switch in a square wave generation device based on a semiconductor switch provided in an embodiment of the present invention.

[0024] Figure 3 This is a schematic diagram of the internal structure of the coaxial reed relay switch in a square wave generation device based on a semiconductor switch provided in an embodiment of the present invention.

[0025] Figure 4 This is a schematic diagram of a semiconductor coaxial switch in a square wave generation device based on a semiconductor switch provided in an embodiment of the present invention.

[0026] Figure 5 This is a schematic diagram of the internal structure of a semiconductor coaxial switch in a square wave generation device based on a semiconductor switch provided in an embodiment of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Example:

[0029] In this embodiment, please refer to the appendix to the specification. Figures 1-5 It provides a square wave generation device based on semiconductor switches.

[0030] A square wave generating device based on a semiconductor switch may include: a power supply 1, a charging resistor 2, a coaxial cable 3, a semiconductor coaxial switch 4, a load 5, and a control module 6.

[0031] In this configuration, power supply 1 is connected to coaxial cable 3 via charging resistor 2, and power supply 1 is connected to semiconductor coaxial switch 4 via charging resistor 2. One end of coaxial cable 3 connected to charging resistor 2 is connected to semiconductor coaxial switch 4.

[0032] The end of the semiconductor coaxial switch 4 that is not connected to the coaxial cable 3 is connected to the load 5. The end of the semiconductor coaxial switch 4 that is not connected to the coaxial cable 3 serves as the output terminal, outputting a square wave.

[0033] Power supply 1 is a high-voltage power supply. The output terminal of power supply 1 can be connected to charging resistor 2 through a high-voltage cable to provide energy to coaxial cable 3 and ensure stable output of charging voltage.

[0034] The charging resistor 2 can be a high-voltage glass glaze resistor. The charging resistor 2 is connected in series between the power supply 1 and the coaxial cable 3 to limit the charging current and prevent excessive current from damaging the coaxial transmission line and coaxial reed relay switch in the coaxial cable 3 when the high voltage provided by the power supply 1 is charging. At the same time, the charging resistor 2 can control the charging time constant so that the coaxial cable 3 can be charged stably.

[0035] The coaxial cable 3 includes several coaxial transmission lines 31, which are connected in series via coaxial reed relay switches 32. The lengths of each coaxial transmission line 31 can be the same, not exactly the same, or completely different. The lengths of the coaxial transmission lines can be set in pulse width increments. For example, for a 50ns square wave, if an RG58 coaxial transmission line is used, 20 coaxial transmission lines 31 can be configured, each 5 meters long.

[0036] The coaxial transmission line 31 can be a low-loss RF coaxial cable, and the characteristic impedance of the selected coaxial transmission line 31 can be matched with the impedance of the load 5.

[0037] Let N be the number of coaxial transmission lines 31, then the corresponding number of coaxial reed relay switches 32 is N-1, where N is a natural number. By controlling the opening and closing of the coaxial reed relay switches 32, the length of the coaxial cable 3 in the circuit is changed, thereby changing the width of the output square wave. Taking a 50ns square wave as an example, when the number of coaxial transmission lines 31 is set to 20, and the length of each coaxial transmission line 31 is 5 meters, then by changing the number of coaxial transmission lines 31 connected to the circuit, the square wave width can be adjusted in 50ns steps within the range of 50ns to 1000ns. Thus, the width of the square wave output by the device is determined by the length of the coaxial cable 3, rather than depending on the drive pulse width, making square wave pulse width adjustment simpler, more efficient, and more precise, solving the problems of inconvenient adjustment in traditional equipment and the difficulty of transmitting extremely narrow drive pulse widths to high-potential gates.

[0038] In an optional embodiment, the coaxial reed relay switch 32 may include: a housing 321, a reed switch 322 disposed within the housing, and a first insulating layer 323 and a second insulating layer 324 disposed between the housing and the reed switch. The first insulating layer 323 is disposed between the reed switch 322 and the second insulating layer 324, and the second insulating layer 324 is disposed between the first insulating layer 323 and the housing 321.

[0039] The reed switch 322 can be a glass-encapsulated reed tube, and SHV high-voltage coaxial connectors can be provided at both ends of the reed switch 322. The housing 321 can be made of brass, and the inner surface of the housing 321 can be nickel-plated. The housing 321 can be regarded as an outer shielding layer, and the reed of the reed switch 322 can be regarded as an inner conductor. Thus, the coaxial reed relay switch 322 constitutes a coaxial shielding structure, which can effectively block electromagnetic interference. The side of the second insulating layer 324 away from the reed switch 322 can be disconnected from the housing 321. The second insulating layer 324 can be made of polytetrafluoroethylene insulating material. The first insulating layer 323 can be made of thermally conductive silicone. The first insulating layer 323 is used to fill the gap between the second insulating layer 324 and the reed switch 322. The first insulating layer 323 can also fill the assembly gaps of the mechanical structure of the coaxial reed relay switch 322. The first insulating layer 323 and the second insulating layer 324 can improve the overall insulation performance of the coaxial reed relay switch 322.

[0040] The coaxial cable 3 can be coiled up.

[0041] Semiconductor coaxial switch 4 is used to control the generation and output of square wave pulses. The characteristic impedance of semiconductor coaxial switch 4 can be slightly less than the impedance of load 5.

[0042] The semiconductor coaxial switch 4 may include a shielding shell 41, a third insulating layer 42, a fourth insulating layer 43, and a semiconductor switch array 44. The semiconductor switch array 44 may include several switches connected in series. A copper rod is connected to the input terminal of the semiconductor switch array 44. The third insulating layer 42 may be disposed between the semiconductor switch array 44 and the fourth insulating layer 43, and the fourth insulating layer 43 may be disposed between the third insulating layer 42 and the shielding shell 41.

[0043] The semiconductor switch array 44 can have several switches connected in series in a line. The switches can be gallium nitride (GaN) power semiconductors; in an optional embodiment, the number of GaN power semiconductors can be 14. The semiconductor switch array 44 can be connected using copper connectors with silver-plated surfaces to reduce overall contact resistance, ensuring stable performance of the semiconductor coaxial switch 4 under high-frequency switching conditions.

[0044] The semiconductor coaxial switch 4 is coaxial in design. The outer shielding shell 41 serves as the outer shielding layer and can be made of brass. The inner surface of the shielding shell 41 is nickel-plated to ensure good conductivity and shielding performance. A copper rod is connected to the input terminal of the semiconductor switch array 44 as an inner conductor. The shielding shell 41 and the copper rod form a coaxial shielding space, enclosing the semiconductor switch array 44 and other core components, effectively blocking electromagnetic interference. The characteristic impedance of the semiconductor coaxial switch 4 is slightly less than the impedance of the load 5, maintaining good impedance matching between the coaxial cable 3 and the load 5. This ensures stable high-frequency signal transmission and voltage output, improves the stability of the semiconductor coaxial switch 4, reduces signal reflection, and solves the problem of existing semiconductor switches being susceptible to electromagnetic interference, which affects waveform quality.

[0045] The fourth insulating layer 43 can be made of polytetrafluoroethylene (PTFE) insulating material, effectively isolating the copper rod from the shielding shell 41. The third insulating layer 42 can be made of thermally conductive silicone. The third insulating layer 42 can be used to fill the gap between the fourth insulating layer 43 and the semiconductor switch array 44. The third insulating layer 42 can also fill the assembly gaps of the mechanical structure of the semiconductor coaxial switch 4, further improving the overall insulation performance of the semiconductor coaxial switch 4, realizing the near-coaxial structure of the semiconductor coaxial switch 4, and ensuring that the semiconductor coaxial switch 4 does not break down under charging voltage and high-frequency operation.

[0046] The semiconductor coaxial switch 4 can have SHV high-voltage coaxial connectors at both its input and output ends; alternatively, an SHV high-voltage coaxial connector can be installed at one end between the input and output ends of the semiconductor coaxial switch 4, while another coaxial connector is installed at the other end. This ensures a good connection between the semiconductor coaxial switch 4 and the coaxial cable 3, effectively controlling impedance abrupt changes.

[0047] In an optional embodiment, the charging resistor 2, the coaxial cable 3, and the semiconductor coaxial switch 4 can be connected via an SHV tee.

[0048] Load 5 can be a thick-film non-inductive resistor. The impedance of load 5 can be equal to the impedance of coaxial cable 3. Thus, the load can stably absorb half of the square wave pulse energy, ensuring the integrity of the square wave waveform and meeting the 1 / 2 charging voltage output requirement.

[0049] The control module 6 can be electrically connected to the coaxial reed relay switch 32 and the semiconductor coaxial switch 4 respectively. The control module 6 can be used to control the on and off of the coaxial reed relay switch 32 and the semiconductor coaxial switch 4.

[0050] The control module 6 can be an STM series microcontroller. It can control the on / off state of the coaxial reed relay switch 32 via a digital output interface. The control module 6 can also be electrically connected to the semiconductor coaxial switch 4 via a semiconductor switch driver module, controlling the on / off state of the semiconductor coaxial switch 4 and achieving precise control over its operating time.

[0051] The semiconductor switch driving module can include several semiconductor switch driving units, each corresponding one-to-one with the switching transistors in the semiconductor coaxial switch 4. The semiconductor switch driving units can be magnetic ring isolated driving units, with the secondary winding of the magnetic ring connected to the gate-source of the switching transistor. The primary winding of the magnetic ring in each semiconductor switch driving unit is connected in series. The control module 6 provides driving signals to the semiconductor switch driving units. These driving signals are coupled to the secondary winding of the magnetic ring through the primary winding, synchronously driving each switch, accelerating the switch turn-on speed, ensuring that the turn-on / turn-off time difference of several switching transistors is less than 0.5ns, guaranteeing consistent operation under high voltage and high frequency switching, avoiding contact bounce problems similar to those of reed switches and the difficulty in controlling gas switches, while also solving the problem of transmitting extremely narrow drive pulse widths to high-potential gates.

[0052] The control terminal of the coaxial reed relay switch 32 is electrically connected to the digital output interface of the control module 6. When the control module 6 issues a closing command, the contacts of the reed switch in the coaxial reed relay switch 32 close, and the corresponding coaxial transmission line 31 is connected to the circuit. When the control module 6 issues a closing command, the contacts of the reed switch in the coaxial reed relay switch 32 open, and the corresponding coaxial transmission line 31 is not connected. Thus, by controlling the closing of different numbers of coaxial reed relay switches 32, the total length of the connected coaxial transmission line 31 is adjusted, resulting in square wave pulses of different widths. The square wave width is determined by the length of the coaxial cable 3 connected, and does not depend on the driving pulse width, ensuring the stability and reliability of the square wave width adjustment.

[0053] The square wave generation device based on semiconductor switches provided by this invention has the following beneficial effects:

[0054] (1) A coaxial reed relay switch is set between coaxial transmission lines. The on and off of the coaxial reed relay switch is controlled by the control module, thereby controlling the length of the coaxial cable. The width of the square wave is determined by the length of the coaxial cable, so that the width of the square wave is not affected by the driving pulse width. The adjustment of the square wave pulse width is more convenient, efficient and accurate, solving the problems of inconvenient adjustment of traditional equipment and difficulty in transmitting the extremely narrow driving pulse width to the high potential gate.

[0055] (2) A semiconductor coaxial switch is set up to improve the output performance of square wave pulse, while meeting the two requirements of high voltage and fast rise time. This satisfies the electromagnetic compatibility field's requirements for high-speed and high-voltage signals, makes up for the shortcomings of traditional mercury wet reed switch tubes in terms of environmental protection, frequency and controllability, and makes up for the defects of gas switches that are difficult to control under normal voltage.

[0056] (3) Optimize the structure of the semiconductor coaxial switch, set the shielding shell as the outer shielding layer, and the copper rod connected to the input end of the semiconductor switch array as the inner conductor. The shielding shell of the semiconductor coaxial switch and the copper rod form a coaxial shielding space, which wraps the core components such as the semiconductor switch array, effectively blocking electromagnetic interference, improving the stability of the semiconductor coaxial switch, reducing signal reflection, and solving the problem that the existing semiconductor switch is easily affected by electromagnetic interference and affects the waveform quality.

[0057] The above description is only an optional embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A square wave generating device based on semiconductor switches, characterized by The device comprises a power supply, a charging resistor, a coaxial cable, a semiconductor coaxial switch, a load and a control module. The power supply is connected to the coaxial cable through the charging resistor. The coaxial cable comprises a plurality of coaxial transmission lines connected in series through coaxial reed switches. The coaxial cable is connected to the load through the semiconductor coaxial switch. The semiconductor coaxial switch comprises a plurality of switch tubes connected in series. The control module is electrically connected to the coaxial reed switches and the semiconductor coaxial switch, and is used to control the on-off of the coaxial reed switches and the semiconductor coaxial switch. The lengths of the coaxial transmission lines are completely identical or not completely identical.

2. The semiconductor-switch-based square wave generating device according to claim 1, characterized by The coaxial reed switch comprises a housing, a reed switch arranged in the housing, a first insulating layer arranged between the housing and the reed switch, and a second insulating layer arranged between the first insulating layer and the housing.

3. The semiconductor-switch-based square wave generating apparatus according to claim 1, wherein The first insulating layer is arranged between the reed switch and the second insulating layer. The second insulating layer is arranged between the first insulating layer and the housing.

4. The semiconductor switch-based square wave generating device according to claim 1, wherein the switch tubes in the semiconductor coaxial switch are connected in series in a straight line.

5. The semiconductor switch-based square wave generating device according to claim 1, wherein the semiconductor coaxial switch comprises a shield layer shell, a third insulating layer, a fourth insulating layer and a semiconductor switch tube array, the semiconductor switch tube array comprises a plurality of switch tubes connected in series, a copper rod is connected to an input end of the semiconductor switch tube array, the third insulating layer is arranged between the semiconductor switch tube array and the fourth insulating layer, and the fourth insulating layer is arranged between the third insulating layer and the shield layer shell.

6. The semiconductor switch-based square wave generating device according to claim 1, wherein the input end and the output end of the semiconductor coaxial switch are provided with SHV high-voltage coaxial connectors.

7. The semiconductor switch-based square wave generating device according to claim 5, wherein the fourth insulating layer is made of polytetrafluoroethylene insulating material.

8. The semiconductor switch-based square wave generating device according to claim 5, wherein the third insulating layer is made of heat-conducting silica gel.

9. The semiconductor switch-based square wave generating device according to claim 5, wherein the shield layer shell is made of brass, and the inner surface of the shield layer shell is plated with nickel.

10. The semiconductor switch-based square wave generating device according to claim 1, wherein the control module is electrically connected to the semiconductor coaxial switch through a semiconductor switch driving module. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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