Coaxial shunt frequency characteristic detection clamp and device

Abstract

A coaxial shunt frequency characteristic detection clamp provided by the present invention comprises a first connection part and a second connection part, the first connection part and the second connection part are coaxially arranged from outside to inside and are both made of a conductive material, the second connection part is matched with the first connection part, and the first connection part is matched with the second connection part. And the second connecting part is used for installing and fixing a coaxial shunt and is electrically connected with the coaxial shunt, and the second connecting part is provided with adaptive impedance corresponding to the signal source and the detection circuit. According to the coaxial shunt frequency characteristic detection clamp provided by the invention, the coaxial shunt is connected and fixed through mutual cooperation of the first connecting part and the second connecting part, and the adaptive impedance corresponding to the signal source and the detection circuit is arranged on the second connecting part, so that the coaxial shunt frequency characteristic detection clamp can be used for detecting the frequency characteristic of the coaxial shunt. And the accuracy of frequency characteristic detection of the coaxial shunt is greatly improved. The invention also provides a coaxial shunt frequency characteristic detection device.

Description

[Technical field]

[0001] The invention relates to the technical field of electronic circuit detection, and in particular to a coaxial shunt frequency characteristic detection fixture and device. [Background technology]

[0002] In the field of electronic measurement, it is often necessary to measure high-frequency (above 100MHz) current waveforms. In order to reduce the parasitic inductance of the shunt, the industry generally uses coaxial shunts to detect high-frequency currents. Figure 1 The figure shows the existing coaxial shunt. The coaxial shunt is provided with an outer conductor, a resistor and a central axis conductor, so that the high-frequency current flows coaxially in opposite directions through the central axis conductor, the resistor and the outer conductor, and the magnetic fields formed by the high-frequency current on the central axis conductor and the outer conductor cancel each other, thereby reducing the measurement of the high-frequency current.

[0003] After the coaxial shunt is manufactured, its frequency characteristics need to be tested. Figure 2 As shown, the frequency f of the high-frequency current signal input to the input end of the coaxial shunt increases from 0HZ. When the frequency f reaches a certain value, the coaxial shunt detection has an error, and the detected signal corresponds to the calculation of the resistor body impedance Rs and begins to increase; when the resistor body impedance Rs changes by more than 3dB, the first frequency value f1 of the frequency f is obtained. If the frequency continues to increase, the error is too large and the coaxial shunt cannot be used normally. At this time, the resistor body impedance Rs and the first frequency value f1 correspond to the various parameters of the detected coaxial shunt frequency characteristics.

[0004] However, the prior art mainly uses simulation analysis and a method of directly welding the coaxial shunt to the signal source and the detection circuit through a wire for detection. Since the impedance of the signal source, the detection circuit or the transmission line does not match the coaxial shunt, the transmitted signal is reflected, and correspondingly, a standing wave is formed on the transmission line, which is especially obvious in high-frequency signal transmission, and ultimately leads to a large error in the detection result, which cannot truly reflect the frequency characteristics of the coaxial shunt. In addition, the existing wire welding method requires welding before testing, and after the test is completed, the solder needs to be removed, which is very inconvenient. [Summary of the invention]

[0005] The present invention provides a coaxial shunt frequency characteristic detection fixture and device for solving the above-mentioned problems of inconvenient measurement and large error, so as to ensure the convenience of detection and improve the accuracy of the detection result.

[0006] The present invention provides a coaxial shunt frequency characteristic detection fixture, comprising a first connecting part and a second connecting part, wherein a receiving cavity is provided inside the first connecting part; the second connecting part is accommodated in the receiving cavity, the first connecting part and the second connecting part are coaxially arranged from the outside to the inside, and are both made of conductive materials, the second connecting part cooperates with the first connecting part, installs and fixes the coaxial shunt and is electrically connected to the coaxial shunt, and the second connecting part is provided with an adaptation impedance corresponding to the signal source and the detection circuit.

[0007] The present invention provides a coaxial shunt frequency characteristic detection device, comprising a signal source, a detection circuit and a coaxial shunt frequency characteristic detection fixture, wherein the signal source is used to generate a high-frequency radio frequency voltage, the detection circuit is used to connect the coaxial shunt and analyze and detect the voltage signal shunted by the coaxial shunt; the coaxial shunt frequency characteristic detection fixture is electrically connected to the signal source and the coaxial shunt respectively, and comprises a first connection part and a second connection part, wherein the first connection part is provided with an accommodating cavity; the second connection part is accommodated in the accommodating cavity, the first connection part and the second connection part are coaxially arranged from the outside to the inside, and are both made of conductive materials, the second connection part cooperates with the first connection part, installs and fixes the coaxial shunt and is electrically connected to the coaxial shunt, and the second connection part is provided with an adaptive impedance corresponding to the signal source and the detection circuit.

[0008] Compared with the prior art, the coaxial shunt frequency characteristic detection fixture provided by the present invention realizes the connection and fixation of the coaxial shunt through the cooperation of the first connection part and the second connection part. The first connection part is used to connect the outer conductor, and the second connection part is used to connect the center axis conductor. The coaxial shunt is connected to the signal source through the coaxial shunt frequency characteristic detection fixture, and there is no need for additional welding wires, so the detection process is more convenient; the first connection part and the second connection part are both made of conductive materials, and the two are coaxially arranged, so that the high-frequency signal used for detection flows through the coaxial shunt frequency characteristic detection fixture without being disturbed by the magnetic field, and by arranging an adaptive impedance corresponding to the signal source and the detection circuit at the second connection part, the accuracy of the coaxial shunt frequency characteristic detection is greatly improved.

[0009] The coaxial shunt frequency characteristic detection device uses the coaxial shunt frequency characteristic detection fixture in conjunction with the signal source and the detection circuit, and can effectively detect the frequency characteristics of the coaxial shunt with high accuracy; the coaxial shunt frequency characteristic detection device is relatively simple as a whole, easy to use and operate, and is suitable for detection and use by manufacturers and users of the coaxial shunt.

Brief Description of the Drawings

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0011] Figure 1 is a cross-sectional view of the coaxial splitter in the prior art;

[0012] Figure 2 is a frequency characteristic waveform diagram of the coaxial shunt test;

[0013] Figure 3 It is a schematic diagram of the framework of the coaxial shunt frequency characteristic detection device provided by the present invention;

[0014] Figure 4 It is a three-dimensional structural schematic diagram of the coaxial shunt frequency characteristic detection fixture provided by the present invention;

[0015] Figure 5 is an exploded view of the coaxial shunt frequency characteristic detection fixture provided by the present invention;

[0016] Figure 6 is a cross-sectional view of the coaxial shunt frequency characteristic detection fixture provided by the present invention;

[0017] Figure 7 is a cross-sectional view of the connection between the coaxial shunt frequency characteristic detection fixture provided by the present invention and the coaxial shunt;

[0018] Figure 8 is a topological diagram of the coaxial shunt frequency characteristic detection device provided by the present invention; and

[0019] Fig. 9 It is a waveform diagram of the frequency characteristic of the coaxial shunt detected by the coaxial shunt frequency characteristic detection device provided by the present invention. [Specific implementation method]

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0022] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0023] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0025] See also Figure 3 The coaxial shunt frequency characteristic detection device 100 includes a signal source 1, a detection circuit 3 and a coaxial shunt frequency characteristic detection fixture 5. The signal source 1 is used to generate a high-frequency radio frequency voltage, the detection circuit 3 is used to connect the coaxial shunt 20, and analyze and detect the voltage signal shunted by the coaxial shunt 20, and the coaxial shunt frequency characteristic detection fixture 5 is electrically connected to the signal source 1 and the coaxial shunt 20 respectively. The coaxial shunt frequency characteristic detection device 100 can realize the electrical connection between the coaxial shunt 20 and the signal source 1 through the coaxial shunt frequency characteristic detection fixture 5, without the need for electrical connection by welding wires, thereby improving the accuracy of the frequency characteristic detection of the coaxial shunt 20.

[0026] It should be noted that the signal source 1 is mainly used to provide a high-frequency radio frequency voltage signal, and its specific structure and implementation method are not limited here. The signal source 1 and the detection circuit 3 can be arranged in one component, which is convenient for carrying, installation and use. For example, the existing vector network analyzer can provide the signal source 1 and the detection circuit 3 at the same time. In order to detect high-frequency current signals, the coaxial shunt 20 is generally provided with a BNC connector structure on the output side. Therefore, the detection circuit 3 and the coaxial shunt 20 can be connected by a coaxial cable (not shown) or directly connected to realize the detection of the coaxial shunt 20, without the need to test by welding wires, thereby further improving the detection accuracy. The coaxial shunt frequency characteristic detection device 100 uses the coaxial shunt frequency characteristic detection fixture 5 in conjunction with the signal source 1 and the detection circuit 3, and can effectively detect the frequency characteristics of the coaxial shunt 20 with high accuracy; the coaxial shunt frequency characteristic detection device 100 is relatively simple as a whole, easy to carry and use, and easy to operate.

[0027] Please also see Figure 4 , Figure 5 , Figure 6 and Figure 7 , are respectively a three-dimensional structural schematic diagram, an exploded view, a cross-sectional view and a cross-sectional view of the coaxial shunt frequency characteristic detection fixture 5 provided by the present invention. The coaxial shunt frequency characteristic detection fixture 5 includes a first connecting portion 51 and a second connecting portion 53. The first connecting portion 51 is provided with a receiving cavity 511; the second connecting portion 53 is received in the receiving cavity 511. The first connecting portion 51 and the second connecting portion 53 are coaxially arranged from outside to inside, and are both made of conductive materials. The second connecting portion 53 cooperates with the first connecting portion 51 to install and fix the coaxial shunt 20 and is electrically connected to the coaxial shunt 20.

[0028] The coaxial shunt frequency characteristic detection fixture 5 can realize accurate transmission of electrical signals between the signal source 1 and the coaxial shunt 20 while installing and fixing the coaxial shunt 20 by coaxially arranging the first connection part 51 and the second connection part 53, and both of them are made of conductive materials, thereby reducing the interference of high-frequency current signals on the detection results. How to reduce interference is specifically described as follows:

[0029] The coaxial shunt 20 includes an outer conductor 21, a central axis conductor 23 and a resistor 25, wherein the first connection portion 51 is electrically connected to the outer conductor 21, and the second connection portion 53 is connected to the central axis conductor 23. The signal source 1 is electrically connected to the coaxial shunt 20 through the first connection portion 51 and the second connection portion 53, and the coaxial shunt frequency characteristic detection fixture 5 is equivalent to a coaxial bidirectional conductor that can be connected to the signal source 1 and the coaxial shunt 20 at the same time. The high-frequency current flowing direction in the first connection portion 51 is the same as that in the outer conductor 21, and the high-frequency current flowing direction in the second connection portion 53 is the same as that in the central axis conductor 23, and the high-frequency current flowing direction in the second connection portion 53 and the central axis conductor 23 is completely opposite to the high-frequency current flowing direction in the first connection portion 51 and the outer conductor 21. Therefore, the magnetic field formed by the high-frequency current flowing through the first connection portion 51 and the second connection portion 53 is exactly offset, and no parasitic inductance is formed, thereby eliminating the interference of the high-frequency current signal on the detection result. The coaxial shunt frequency characteristic detection fixture 5 forms the same effect of eliminating high-frequency current signal interference as the coaxial shunt 20 through the coaxial arrangement of the first connecting portion 51 and the second connecting portion 53, thereby improving the measurement accuracy.

[0030] Of course, it should be noted that the first connection part 51 and the second connection part 53 are not electrically connected to each other, and the relative position between the two can be fixed by setting an insulating member 55. The specific structure and setting position of the insulating member 55 are not further restricted here.

[0031] In order to improve the adaptability of the coaxial shunt frequency characteristic detection fixture 5, the second connection part 53 is provided with an adaptation impedance 57 corresponding to the signal source 1 and the detection circuit 3. Since the signal source 1 and the detection circuit 3 both have a certain impedance, and the resistance of the resistor 25 in the coaxial shunt 20 is very low and can be ignored, in order to ensure that the coaxial shunt 20 detects the frequency characteristics more accurately, it is necessary to match the coaxial shunt 20 with an adaptation impedance 57 that meets the requirements. The first connection part 51 and the second connection part 53 are both made of conductive materials, and a certain adaptation impedance 57 is respectively set on the first connection part 51 and the second connection part 53, or both are set, and then connected to the coaxial shunt 20, the whole is connected to the signal source 1 and the detection circuit 3, so that the impedance of each part remains consistent, thereby improving the detection accuracy of the coaxial shunt 20.

[0032] In this embodiment, the resistance value of the adaptation impedance 57 is selected to be 50 ohms. Currently, in the devices on the market for providing the signal source 1 or the detection circuit 3, the inherent impedance is 50 ohms. For example, various types of vector network analyzers on the market have the internally set signal source 1 and the detection circuit 3 with an impedance of 50 ohms. Therefore, by setting the adaptation impedance 57 to 50 ohms, it can be ensured that the coaxial shunt frequency characteristic detection fixture 5 can have a wider range of usage scenarios, and the accuracy of the frequency characteristic detection of the coaxial shunt 20 can be effectively improved.

[0033] In order to further solve the reliability problem of the adaptation impedance 57, the second connection part 53 includes a resistor R for providing the adaptation impedance 57. The second connection part 53 can directly weld a 50-ohm resistor to provide the adaptation impedance 57. The first connection part 51 does not need to be connected separately, which is convenient for installation and easy to detect and identify. The second connection part 53 is arranged in the accommodating cavity 511 and is protected by the first connection part 51 on the outer peripheral side to ensure that the adaptation impedance 57 is not disturbed by the external environment and to improve the service life of the adaptation impedance 57. In addition, when the resistor R fails, it is also convenient to replace it, and a new resistor R can be re-welded.

[0034] Of course, in order to facilitate disassembly and replacement, the second connection part 53 can be movably connected to the first connection part 51. When one of the first connection part 51 or the second connection part 53 has a problem, it can be replaced separately, thereby saving costs. After the resistor R is damaged, the second connection part 53 can be disassembled, the resistor R can be replaced separately, and then the second connection part 53 can be installed in the accommodating cavity 511. There are many ways to flexibly connect the first connection part 51 and the second connection part 53. For example, the insulating member 55 set in the accommodating cavity 511 has an elastic mounting hole 551 in the middle, and the insulating member 55 is fixedly connected to the first connection part 51. One side of the second connection part 53 is set in a pin shape, which is matched with the mounting hole 551. One side of the second connection part 53 can be freely inserted into the mounting hole 551 and is well fixed in position; when it needs to be removed, it only needs to be pulled out with force. Of course, it can also be set to other plug-in, threaded or clamping structures, which are not limited here.

[0035] In this embodiment, the first connection part 51 is a cylindrical structure as a whole, and a BNC connector is provided at one end. The first connection part 51 is used to connect and fix the signal source 1 and the outer conductor 21, and is also used to cooperate with the second connection part 53 to perform coaxial reverse current conduction. It has the dual functions of a connector and a conductive part at the same time, and is set to a cylindrical structure, which is not only convenient for connection and installation, but also can be adapted to the second connection part 53 as much as possible, reducing the interference of the magnetic field formed by the high-frequency current signal on the frequency characteristic detection of the coaxial shunt 20. In addition, by setting one end of the first connection part 51 as the BNC connector, it is convenient for the coaxial shunt frequency characteristic detection fixture 5 to be electrically connected with the coaxial cable or various types of the signal source 1; and the BNC connector is to set the insulating part 55 to separate the inner and outer conductors 21, so that the second connection part 53 can also be better adapted and connected with the first connection part 51, and can be freely disassembled and assembled.

[0036] In order to make an electrical connection with the coaxial shunt 20, a connector 533 is provided at one end of the second connecting portion 53 for electrically connecting to the central axis conductor 23 of the coaxial shunt 20; the first connecting portion 51 is provided with an abutment 513 and / or a limiting member 515, and the abutment 513 and / or the limiting member 515 cooperate with the connector 533 for installing the coaxial shunt 20 and electrically connecting to the outer conductor 21 of the coaxial shunt 20.

[0037] In order to facilitate the use and installation of the coaxial shunt 20, the central axis conductor 23 is generally set to penetrate the outer conductor 21, and the central axis conductor 23 and the outer conductor 21 are also coaxially arranged cylindrical or columnar structures. The second connecting part 53 and the central axis conductor 23 can be fully connected and fixed by the connector 533, but there may be a gap or gap between the first connecting part 51 and the outer conductor 21. Therefore, the combination of the abutment 513 and / or the limiter 515 can ensure that the first connecting part 51 and the outer conductor 21 are fully electrically connected. The abutment 513 and the limiter 515 can be used alone or set at the same time, and no further restrictions are made here.

[0038] It should be noted that the connection between the connector 533 and the central axis conductor 23 can be threaded, welded, or snap-fitted. The connector 533, the abutment member 513, and the stopper 515 mentioned above are also made of conductive materials, and are used to connect and fix the coaxial shunt 20 while achieving electrical connection.

[0039] Please continue to refer to Figure 8 , Figure 81 is a topological diagram of the coaxial shunt frequency characteristic detection device 100 provided by the present invention. The working principle of the coaxial shunt frequency characteristic detection device using the coaxial shunt frequency characteristic detection fixture is summarized as follows:

[0040] In the entire circuit connection relationship, the signal source 1 is provided with a signal source impedance R1, the detection circuit 3 is provided with a detection impedance R2, the coaxial shunt frequency characteristic detection fixture 5 is provided with the resistor R, and the coaxial shunt 20 is provided with the resistor body impedance Rs.

[0041] The two ends of the signal source 1 provide a high-frequency RF voltage U1, and the coaxial shunt frequency characteristic detection fixture 5 and the coaxial shunt 20 together form a similar load structure. The high-frequency RF current I flows through the coaxial shunt frequency characteristic detection fixture 5 and the coaxial shunt 20. The two ends of the detection circuit 3 detect the voltage U2 across the resistor body impedance Rs after the coaxial shunt 20 shunted. Among them, U1 / (R+Rs)=I, U2=I·Rs. The resistance value of the resistor body impedance Rs is generally between 0.1 ohms and 0.001 ohms. The resistance values ​​of the signal source impedance R1, the detection impedance R2 and the resistor R are all 50 ohms, which is much larger than the resistance value of the resistor body impedance Rs, so U2=U1·Rs / R.

[0042] Since the impedance of each structure in the whole detection system is consistent and matched with each other, the value of the resistor body impedance Rs will not fluctuate during the detection process on the basis of relatively accurate detection of U2 and U1, and can truly reflect the real frequency characteristics of the coaxial shunt 20.

[0043] Please continue to combine Fig. 9 , Fig. 9 This is a waveform diagram of the frequency characteristic of the coaxial shunt detected by the coaxial shunt frequency characteristic detection device provided by the present invention. The frequency characteristic is further described as follows:

[0044] The detection result of the resistor body impedance Rs is shown in the waveform graph as the frequency f changes. In the initial stage, the resistor body impedance Rs remains unchanged. As the frequency f continues to increase and reaches the first frequency value f1, due to the existence of the adaptation impedance 57, the resistor body resistance Rs remains within the range of ±3dB. Until the frequency f increases to the second frequency value f2, the resistor body resistance Rs will change significantly. This change is mainly caused by the leakage of high-frequency radio frequency signals and is related to the production process and mechanical structure. Through the setting of the adaptation impedance 57, the second frequency value f2 can basically reach 2GHz, while the first frequency value f1 is generally 1GHz. The second frequency value f2 is the maximum operating frequency value truly reflected by the coaxial shunt 20. Since the adaptation impedance 57 is set in the coaxial shunt frequency characteristic detection fixture 5, the coaxial shunt frequency characteristic detection device 100 can more effectively detect the frequency characteristics of the coaxial shunt 20.

[0045] The coaxial shunt frequency characteristic detection fixture 5 is used in the coaxial shunt frequency characteristic detection device 100 to provide an effective detection environment for the detection of the coaxial shunt 20, reduce the influence of impedance mismatch on the detection result, and thus detect the accurate frequency characteristic of the coaxial shunt.

[0046] In addition, the coaxial shunt frequency characteristic detection fixture 5 can achieve a close fit between the coaxial shunt frequency characteristic detection fixture 5 and the coaxial shunt 20 by providing the connector 533, the abutment member 513 and the limit member 515, thereby improving the stability of detection.

[0047] The above description is only an implementation mode of the present invention. It should be pointed out that, for ordinary technicians in this field, improvements can be made without departing from the creative concept of the present invention, but these all belong to the protection scope of the present invention.

Claims

1. A coaxial shunt frequency characteristic detection fixture, used to assist the coaxial shunt to be connected to a signal source and a detection circuit, and to detect the frequency characteristics, characterized in that: include: A first connecting portion, wherein a containing cavity is provided inside the first connecting portion; and The second connecting part is accommodated in the accommodating cavity, the first connecting part and the second connecting part are coaxially arranged from the outside to the inside, and are both made of conductive materials, the second connecting part cooperates with the first connecting part, installs and fixes the coaxial shunt and is electrically connected to the coaxial shunt, and the second connecting part is provided with an adaptation impedance corresponding to the signal source and the detection circuit.

2. The coaxial shunt frequency characteristic detection fixture according to claim 1, characterized in that: The resistance of the adaptation impedance is 50 ohms.

3. The coaxial shunt frequency characteristic detection fixture according to claim 1, characterized in that: The second connecting portion includes a resistor for providing the adaptation impedance.

4. The coaxial shunt frequency characteristic detection fixture according to claim 1, characterized in that: The second connection portion is movably connected to the first connection portion.

5. The coaxial shunt frequency characteristic detection fixture according to claim 1, characterized in that: A connector is provided at one end of the second connecting portion, which is used to electrically connect the central axis conductor of the coaxial shunt. The first connecting portion is provided with an abutment and / or a limiter, and the abutment and / or the limiter cooperate with the connector to install the coaxial shunt and electrically connect the outer conductor of the coaxial shunt.

6. The coaxial shunt frequency characteristic detection fixture according to claim 1, characterized in that: The first connecting portion is a cylindrical structure as a whole, and a BNC connector is provided at one end.

7. A coaxial shunt frequency characteristic detection device, used for detecting the frequency characteristic of the coaxial shunt, comprising: A signal source for generating a radio frequency voltage; A detection circuit, used for connecting the coaxial shunt and analyzing and detecting a voltage signal shunted by the coaxial shunt; and The coaxial shunt frequency characteristic detection fixture according to any one of claims 1 to 7, wherein the coaxial shunt frequency characteristic detection fixture is electrically connected to the signal source and the coaxial shunt, respectively.

8. The coaxial shunt frequency characteristic detection device according to claim 7, characterized in that: It also includes a coaxial cable, which is arranged between the detection circuit and the coaxial shunt.

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