Deembedding circuit for acquiring characteristic parameters of millimeter wave peripheral circuit

Abstract

The utility model discloses a de-embedding circuit used for obtaining millimeter wave peripheral circuit characteristic parameters. The de-embedding circuit comprises a PCB, a millimeter wave test circuit arranged on the PCB, and a de-embedding circuit which carries out mirror image setting with the millimeter wave test circuit on the PCB by taking a mirror image reference surface as a reference. The system further comprises S parameter measuring equipment; the S parameter measurement device is connected with the millimeter wave test circuit and the de-embedding circuit. According to the utility model, the influence of a microstrip circuit and a connector on a millimeter wave chip channel on a chip device can be eliminated.

Description

Technical Field

[0001] The utility model relates to the technical field of microwave millimeter waves, in particular to a de-embedding circuit for acquiring characteristic parameters of a millimeter wave peripheral circuit. Background Art

[0002] The microwave millimeter wave band has been widely used in communications, imaging, radar, etc. due to its short wavelength, wide bandwidth, all-weather, and strong adaptability to smoke. With the development of millimeter wave technology, people's demand for various millimeter wave circuits is also increasing. However, due to its short wavelength and attenuation in space and microstrip circuits, the chip is greatly affected by external circuits during use, such as signal attenuation. In actual use, since one end is connected to the chip circuit, how to remove the external influence and obtain the real response of the millimeter wave chip circuit has become an important issue in the chip design and use process. At present, some people have changed the connector form from parallel connection to vertical connection, so that the attenuation can be reduced by reducing the size of the curved waveguide. Some people have changed the structural form of the curved waveguide to reduce the loss, but they cannot completely eliminate the impact of the millimeter wave circuit.

[0003] In the prior art, the utility model patent with the patent publication number CN117673689A provides a millimeter wave attenuation structure and a millimeter wave chip testing method, which discloses that a microstrip top metal layer having a first microstrip metal line and a second microstrip metal line is formed on the stacked ground metal layer and the intermediate dielectric layer, and the characteristic impedance corresponding to the second microstrip metal line is smaller than the characteristic impedance corresponding to the first microstrip metal line, so that the first microstrip metal lines can be coupled and transmitted, forming a millimeter wave attenuation structure with 1 signal input port, 1 signal output port and 2 auxiliary signal output ports, and a considerable signal attenuation can be obtained. The prior art is the above-mentioned millimeter wave attenuation characteristics in space and microstrip circuits, which makes the chip greatly affected by external circuits during use. Utility Model Content

[0004] The technical problem to be solved by the utility model is to solve the problem that the existing technology cannot remove the external influence and obtain the real response of the millimeter wave chip circuit.

[0005] In order to solve the above technical problems, the utility model provides the following technical solutions:

[0006] A de-embedding circuit for obtaining characteristic parameters of a millimeter wave peripheral circuit, comprising: a PCB board (10) and a millimeter wave test circuit (20) arranged on the PCB board (10), and a de-embedding circuit (40) mirror-arranged with the millimeter wave test circuit (20) on the PCB board (10) with a mirror reference plane (30) as a reference; and further comprising an S parameter measuring device; the S parameter measuring device is respectively connected to the millimeter wave test circuit (20) and the de-embedding circuit (40);

[0007] The millimeter wave test circuit (20) comprises at least one test connector (21) and a test curved waveguide (22) connected to the test connector (21); correspondingly, the de-embedding circuit (40) comprises a de-embedding connector (41) and a de-embedding curved waveguide (42) connected to the de-embedding connector (41); and the de-embedding curved waveguide (42) and the test curved waveguide (22) are connected at a mirror reference plane (30) so that the test connector (21) and the de-embedding connector (41) are directly connected; and the test connector (21) and the de-embedding connector (41) are respectively connected to the test port of the S parameter measurement device.

[0008] Advantages: By testing and calculating the de-embedded circuit, the characteristic parameters of the millimeter-wave peripheral circuit can be indirectly obtained. Then, through matrix operations, the peripheral circuit characteristics can be completely removed from the millimeter-wave circuit test.

[0009] In one embodiment of the utility model, the millimeter wave test circuit (20) is manufactured according to the structure of the millimeter wave chip test circuit (A) to be tested, and is obtained by removing the chip in the millimeter wave chip test circuit to be tested.

[0010] In one embodiment of the utility model, the mirror reference plane (30) is located on the PCB board (10) with the position of the chip in the millimeter wave chip test circuit (A) to be tested as a reference.

[0011] In one embodiment of the utility model, the chip position in the millimeter wave chip test circuit (A) to be tested is used as the calibration plane (11), and the mirror reference plane (30) can be fine-tuned in the calibration plane (11) in the mirror direction.

[0012] In an embodiment of the present invention, the de-embedding circuit is suitable for an E-band test range.

[0013] In one embodiment of the utility model, the test curved waveguide (22) and the de-embedded curved waveguide (42) are coplanar on the PCB board (10).

[0014] In an embodiment of the present invention, the S parameter measurement device is a vector network analyzer.

[0015] In one embodiment of the utility model, the test connector (21) is located at the edge of the PCB board (10); and the test curved waveguide (22) is coaxially crimped with the test connector (21).

[0016] Compared with the prior art, the utility model has the beneficial effect of removing the influence of the microstrip circuit and the connector on the millimeter wave chip path on the chip device. Compared with the prior art, the utility model is more convenient to implement, the production cost is lower and more convenient, and it can effectively remove the influence of the peripheral structure of the millimeter wave circuit on it, and quickly obtain the chip performance in the circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The present invention is a schematic diagram of a de-embedding circuit for obtaining characteristic parameters of a millimeter-wave peripheral circuit according to an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of a test circuit for a millimeter-wave chip to be tested according to an embodiment of the utility model.

[0019] Figure 3 Schematic diagram of return loss and insertion loss of the millimeter wave chip test circuit to be tested according to an embodiment of the utility model.

[0020] Figure 4 It is a schematic diagram of the return loss and insertion loss of the test circuit of the millimeter wave chip to be tested after using the de-embedding circuit according to an embodiment of the utility model. DETAILED DESCRIPTION

[0021] In order to facilitate those skilled in the art to understand the technical solution of the utility model, the technical solution of the utility model is further explained in conjunction with the drawings in the specification.

[0022] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0023] See also Figure 1 As shown, the utility model provides a de-embedding circuit for obtaining characteristic parameters of a millimeter wave peripheral circuit, comprising: a PCB board 10 and a millimeter wave test circuit 20 arranged on the PCB board 10, and a de-embedding circuit 40 mirror-arranged with the millimeter wave test circuit 20 on the PCB board 10 with a mirror reference plane 30 as a reference. It also includes an S parameter measurement device, which is connected to the millimeter wave test circuit 20 and the de-embedding circuit 40 respectively.

[0024] See also Figure 1 As shown, in one embodiment of the utility model, the millimeter wave test circuit 20 includes at least one test connector 21, and a test bend waveguide 22 connected to the test connector 21. Specifically, the test connector 21 is fixed to the edge of the PCB board 10 by a fastener, such as a fastening screw, and the test bend waveguide 22 transmits the millimeter wave signal and is coaxially crimped with the test connector 21. Undoubtedly, the de-embedding circuit 40, which is mirror-set to the millimeter wave test circuit 20, corresponds to the de-embedding connector 41, and the de-embedding bend waveguide 42 coaxially crimped to the de-embedding connector 41. Among them, the test bend waveguide 22 and the de-embedding bend waveguide 42 are coplanar on the PCB board 10 and connected at the mirror reference plane 30, so that the two ports of the test connector 21 and the de-embedding connector 41 are directly connected, so that the millimeter wave test circuit 20 and the de-embedding circuit 40 are used as a whole, and the test connector 21 and the de-embedding connector 41 are used as two-port direct-through devices that can be measured.

[0025] See also Figure 1 and Figure 2 As shown, in one embodiment of the present invention, the millimeter wave test circuit 20 is made according to the structure of the millimeter wave chip test circuit A to be tested, and the chip in the millimeter wave chip test circuit to be tested is removed. It should be noted that Figure 2 The millimeter-wave chip test circuit A to be tested is only an example. The size of the millimeter-wave test circuit 20 must depend on and match the structure of the millimeter-wave chip test circuit A to be tested. The specific structure of the millimeter-wave test circuit 20 is determined according to the actual millimeter-wave chip test circuit to be tested.

[0026] See also Figure 1 and Figure 2 As shown, in one embodiment of the present invention, the mirror reference plane 30 is located on the PCB board 10, and is set based on the chip position in the millimeter wave chip test circuit A to be tested. The chip position in the millimeter wave chip test circuit A to be tested is used as the calibration plane 11, and the mirror reference plane 30 can be set in the mirror direction (such as Figure 1 The calibration plane 11 is fine-tuned in the direction of the arrow. This involves the concept of a "calibration plane" in the test in the technical field. In layman's terms, it is the position where the user needs to remove the error. That position is called the calibration plane. When applied to this embodiment, it means that the mirror reference plane 30 can be adjusted in the mirror direction according to actual use requirements, and fine-tuned in the calibration plane 11 to achieve the best error removal effect.

[0027] See also Figure 1As shown, in one embodiment of the present invention, the test connector 21 and the de-embedding connector 41 are respectively connected to the test port of the S parameter measurement device (not shown in the figure). Specifically, the S parameter measurement device is a vector network analyzer. The present application does not improve the vector network analyzer, which is a product available on the market. Specifically, the de-embedding circuit of the present application is suitable for the E-band test range.

[0028] See also Figure 1 and Figure 2 As shown, in one embodiment of the present invention, when used: the S parameter measuring device performs S parameter testing on the test connector 21 and the de-embedding connector 41, and the S parameters include four quantities S11, S22, S12 and S21, which respectively represent the end return loss and the transmission coefficient. Specifically, S11 represents the input return loss, S22 represents the output return loss, S12 is the reverse transmission coefficient, and S21 is the forward transmission coefficient. These four parameters can describe the microwave RF parameter characteristics from the test connector 21 to the de-embedding connector 41. For the port return loss and transmission coefficient from the test connector 21 to the de-embedding connector 41, the matrix operation function of the S parameter measuring device is used to calculate the microwave RF parameter characteristics from the test connector 21 to the mirror reference plane 30, including the RF characteristic information of the test connector 21 and the test curved waveguide 22.

[0029] See also Figure 1 and Figure 2 As shown, in one embodiment of the present invention, when the millimeter wave chip test circuit A to be tested tests the chip, the chip radio frequency characteristic information is obtained. The millimeter wave test circuit 20 obtained according to the structure of the millimeter wave chip test circuit A to be tested after removing the chip is used, and the de-embedding circuit made therefrom is used in conjunction with a vector network analyzer to obtain the radio frequency characteristic information of the corresponding test connector 21 and the test curved waveguide 22. The signal processing device is used to remove the radio frequency characteristic information of the corresponding test connector 21 and the test curved waveguide 22 from the chip radio frequency characteristic information to obtain the radio frequency characteristic information of the chip itself.

[0030] Example

[0031] The operating frequency band is set to 77 GHz, and the width of the two curved waveguides in the test circuit A of the millimeter-wave chip to be tested is 2.26 mm, the bending radius is greater than a quarter wavelength of 77 GHz, and the port impedance is 50 ohms. There is no doubt that the line width of the test curved waveguide 22 and the de-embedded curved waveguide 42 of the present application are both 2.26 mm, the bending radius is greater than a quarter wavelength of 77 GHz, and the port impedance is 50 ohms, which matches the test circuit A of the millimeter-wave chip to be tested. The test circuit A of the millimeter-wave chip to be tested performs chip RF testing, and the obtained return loss (curve with triangle symbols) and insertion loss (curve with square symbols) are as shown in the figure. Figure 3As shown, after applying the de-embedding circuit of the utility model, the return loss and insertion loss of the chip itself are obtained as shown in FIG. Figure 4 As shown. Among them, Figure 4 In the figure, because of the mirror characteristics, the most significant insertion loss here is twice the relationship, and the return loss is less than -10dB.

[0032] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any figure mark in the claims should not be regarded as limiting the claims involved.

[0033] The above-described embodiments merely represent implementation methods of the utility model, and the protection scope of the utility model is not limited to the above-described embodiments. For those skilled in the art, several modifications and improvements can be made without departing from the concept of the utility model, and all of these belong to the protection scope of the utility model.

Claims

1. A de-embedding circuit for obtaining characteristic parameters of a millimeter-wave peripheral circuit, characterized in that: include: A PCB board (10) and a millimeter wave test circuit (20) arranged on the PCB board (10), and a de-embedding circuit (40) mirror-arranged with the millimeter wave test circuit (20) on the PCB board (10) with a mirror reference plane (30) as a reference; and an S parameter measuring device; the S parameter measuring device is respectively connected to the millimeter wave test circuit (20) and the de-embedding circuit (40).

2. The de-embedding circuit for obtaining characteristic parameters of a millimeter-wave peripheral circuit according to claim 1, characterized in that: The millimeter wave test circuit (20) comprises at least one test connector (21) and a test curved waveguide (22) connected to the test connector (21); correspondingly, the de-embedding circuit (40) comprises a de-embedding connector (41) and a de-embedding curved waveguide (42) connected to the de-embedding connector (41); and the de-embedding curved waveguide (42) and the test curved waveguide (22) are connected at a mirror reference plane (30) so that the test connector (21) and the de-embedding connector (41) are directly connected.

3. The de-embedding circuit for obtaining characteristic parameters of a millimeter-wave peripheral circuit according to claim 2, characterized in that: The test connector (21) and the de-embedding connector (41) are respectively connected to the test ports of the S parameter measurement device.

4. The de-embedding circuit for obtaining characteristic parameters of a millimeter-wave peripheral circuit according to claim 1, characterized in that: The millimeter wave test circuit (20) is manufactured according to the structure of the millimeter wave chip test circuit (A) to be tested, and is obtained by removing the chip in the millimeter wave chip test circuit to be tested.

5. The de-embedding circuit for obtaining characteristic parameters of a millimeter-wave peripheral circuit according to claim 1, characterized in that: The position of the mirror reference plane (30) on the PCB board (10) is set based on the position of the chip in the millimeter wave chip test circuit (A) to be tested.

6. The de-embedding circuit for obtaining characteristic parameters of a millimeter-wave peripheral circuit according to claim 5, characterized in that: The chip position in the millimeter wave chip test circuit (A) to be tested is used as a calibration plane (11), and the mirror reference plane (30) can be fine-tuned in the calibration plane (11) in the mirror direction.

7. The de-embedding circuit for obtaining characteristic parameters of a millimeter-wave peripheral circuit according to claim 1, characterized in that: The de-embedding circuit is suitable for E-band test range.

8. The de-embedding circuit for obtaining characteristic parameters of a millimeter-wave peripheral circuit according to claim 1, characterized in that: The test curved waveguide (22) and the de-embedded curved waveguide (42) are coplanar on the PCB board (10).

9. The de-embedding circuit for obtaining characteristic parameters of a millimeter-wave peripheral circuit according to claim 1, characterized in that: The S parameter measurement device is a vector network analyzer.

10. The de-embedding circuit for obtaining characteristic parameters of a millimeter-wave peripheral circuit according to claim 2, characterized in that: The test connector (21) is located at the edge of the PCB board (10); the test curved waveguide (22) is coaxially crimped with the test connector (21).

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