CN114690106A - A calibration method of radio frequency test tooling - Google Patents

Abstract

A method for calibrating a radio frequency test tool, the radio frequency test tool includes a test instrument and a shielding box, the test instrument has a first signal interface and a second signal interface, a fixing table is arranged in the shielding box, and the fixing table A coupling plate is installed on the shielding box, a first connection point and a second connection point are arranged on the side wall of the shielding box, the second signal interface and the second connection point are connected by a third cable, the The second connection point and the coupling plate are connected by a fourth cable. The calibration method includes the following steps: measuring the line loss of the entire loop, measuring the line loss of the fifth cable, and measuring the sum of the line losses of the first cable and the second cable; calculating a radio frequency test fixture line loss. Adopting this calibration method can greatly improve the efficiency of RF test tool calibration, and at the same time greatly reduce the cost.

Description

A calibration method of radio frequency test tooling

technical field

The invention relates to the field of electronic equipment manufacturing and testing, in particular to a calibration method of a radio frequency test tool.

Background technique

In the R&D and production process of RF products, it is essential to test the relevant parameters of RF products (such as transmit power, frequency error, phase error, receiving sensitivity, etc.). In the prior art, a comprehensive tester is used to detect the radio frequency index of the product's radio frequency signal. During the detection, the comprehensive tester needs to connect the product through a radio frequency line, and the radio frequency line also has signal attenuation. When the RF index is detected, the RF line needs to be calibrated.

At present, the industry generally adopts the gold machine mode for calibration. Here, the gold machine is a product whose various indicators and parameters are adjusted to fixed optimal values. During the test, the gold machine is connected to the comprehensive tester through the radio frequency line. The RF index of the gold machine is determined, so the gold machine can be used as a standard to calibrate the RF line and the comprehensive tester at the same time. The biggest disadvantage of this calibration method is:

1) In the NPI stage, it is generally too late to generate gold machines, so there are obvious deficiencies in the production timeliness;

2) In the NPI stage, it is usually necessary to replace the gold machine frequently, resulting in the high level of research and development and production of finished products.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a calibration method of a radio frequency test tool, which aims to solve the problems of low efficiency and high cost of radio frequency test in the NPI stage of existing radio frequency products.

In order to solve the above-mentioned technical problems, the technical solution adopted in the invention is to provide a calibration method of a radio frequency test tool, the radio frequency test tool includes a test instrument and a shielding box, and the test instrument has a first signal interface and a second signal interface, The shielding box is provided with a fixing table, a coupling plate is installed on the fixing table, a first connection point and a second connection point are arranged on the side wall of the shielding box, and the second signal interface is connected with the first connection point. The two connection points are connected by a third cable, and the second connection point and the coupling plate are connected by a fourth cable; the calibration method includes the following steps:

Step S1, install the device under test on the fixed table, connect the first signal interface and the first connection point with the first cable connection, and connect the fifth signal interface at one end of the device under test. cable, connect the fifth cable to the first cable with a second cable, measure the line loss of the entire loop, and record the measurement result as Loss1;

Step S2, measure the line loss of the fifth cable, and record the measurement result as Loss2;

Step S3, separate the first cable from the first connection point, separate the third cable from the second signal interface, take out the second cable, and remove the second cable The two ends of the first cable are respectively connected to the end of the first cable and the second signal interface, the sum of the line losses of the first cable and the second cable is measured, and the measurement result is recorded as Loss3;

In step S4, the line loss of the radio frequency test tool is calculated according to the following formula: Loss=Loss1-Loss2-Loss3, where Loss is the line loss of the radio frequency test tool.

In the above technical solution, the line loss Loss1 of the entire circuit, the line loss Loss2 of the fifth cable, the line loss and Loss3 of the first cable and the second cable are measured successively through the above steps, and then according to the formula The line loss Loss of the RF test tool can be obtained by calculation, and the rapid calibration of the RF test tool can be realized. The entire calibration process is simple and easy to implement. Most importantly, it does not need to use a gold machine, which can greatly improve the efficiency of RF test tool calibration and greatly reduce costs.

In the calibration method of the radio frequency test tool provided by the present invention, the device to be tested includes a PCB board, and an antenna and an antenna matching element mounted on the PCB board.

In the calibration method of the radio frequency test tool provided by the present invention, the test instrument is an RF test instrument.

In the calibration method of the radio frequency test tool provided by the present invention, a first installation cavity is provided on the solid state stage, and the coupling plate is fixed in the first installation cavity.

In the calibration method of the radio frequency test tool provided by the present invention, the solid-state table is provided with a second installation cavity; in the step S1, in the step of "installing the device to be tested on the fixed table" , is to fix the device under test in the second installation cavity.

In the calibration method of the radio frequency test tool provided by the present invention, the fifth cable includes a radio frequency wire and a radio frequency terminal.

Implementing the calibration method of the radio frequency test fixture of the present invention can at least achieve the following beneficial effects: through the above steps, the line loss Loss1 of the entire circuit, the line loss Loss2 of the fifth cable, the first cable and the second cable are measured successively. The line loss and Loss3 of the cable can be calculated according to the formula to obtain the line loss Loss of the RF test tool, which realizes the rapid calibration of the RF test tool. The entire calibration process is simple and easy to implement. Most importantly, it does not need to use a gold machine, which can greatly improve the efficiency of RF test tool calibration and greatly reduce costs.

Description of drawings

In order to illustrate the embodiments of the invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that are used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only For the embodiment of the invention, for those of ordinary skill in the art, other drawings can also be obtained according to the provided drawings without creative work:

1 is a schematic diagram of line connections when measuring the line loss of the entire loop in the calibration method provided in the embodiment of the present invention;

2 is a schematic diagram of line connections when measuring the sum of line losses of a first cable and a second cable in a calibration method provided in an embodiment of the present invention;

FIG. 3 is a flowchart of steps of a calibration method provided by an embodiment of the present invention.

Description of the reference numerals in the specific embodiment:

shielding box 11 test instrument 12 first signal interface 121 second signal interface 122 Fixed table 111 coupling plate 1111 first connection point 112 second connection point 113 first cable 13 second cable 14 third cable 15 Fourth cable 16 equipment under test 2 Fifth cable 3

Detailed ways

In order to facilitate understanding of the invention, the invention will be described more fully below with reference to the associated drawings. Typical embodiments of the invention are set forth in the accompanying drawings. However, the invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of the invention. The terms used herein in the description of the invention are for the purpose of describing particular embodiments only and are not intended to limit the invention.

This embodiment provides a calibration method for a radio frequency test tool.

In order to facilitate understanding of the calibration method provided in this embodiment, it is necessary to first describe the radio frequency test tool. Referring to FIG. 1 , the RF testing tool includes a testing instrument 12 and a shielding box 11 . The test instrument 12 is an RF test instrument 12. Here, we choose an RF test instrument 12 with a model of CMW500. The test instrument 12 has a first signal interface 121 and a second signal interface 122. Here, the first The signal interface 121 is a signal transmitting end, and the second signal interface 122 is a signal receiving end. The shielding box 11 is a hollow cuboid structure, which may be made of aluminum. There is a fixing table 111 inside, and the coupling plate 1111 is installed on the fixing table 111 . Here, the solid state stage is provided with a first installation cavity and a second installation cavity, and the coupling plate 1111 is fixed in the first installation cavity. The vertical side wall of the shielding box 11 is provided with a first connection point 112 and a second connection point 113. Here, the first connection point 112 and the second connection point 113 respectively penetrate the side wall. a first metal terminal and a second metal terminal. The second signal interface 122 and the second connection point 113 are connected by a third cable 15 , and the second connection point 113 and the coupling plate 1111 are connected by a cable provided in the shielding box 11 . The fourth cable 16 is connected.

The second cable 14 connected to the first connection point 112, the first signal interface 121 and the first connection point 112 are connected through the first cable 13,

Referring to FIG. 1 , the point indicated by A in the figure is the end of the second cable 14 connected to the fifth cable 3 , and the point indicated by B is the connection between the fourth cable 16 and the fifth cable 3 . The end where the coupling plate 1111 is connected, the point indicated by C is the end of the third cable 15 that is connected to the second signal interface 122 , and the point indicated by D is the end of the first cable 13 connected to the second signal interface 122 . The end connected to the first signal interface 121 . Referring to FIG. 2, the calibration method provided by this embodiment includes the following steps:

Step S1 , referring to FIG. 1 , install the device under test 2 on the fixing table 111 , connect the first signal interface 121 with the first connection point 112 with the first cable 13 , and connect the first signal interface 121 to the first connection point 112 . One end of the device under test 2 is connected to the fifth cable 3, and the second cable 14 is used to connect the fifth cable 3 to the first cable 13. In this way, the line loss of the entire circuit can be measured, and the Record the measurement result as Loss1;

Step S2, measure the line loss of the fifth cable 3, and record the measurement result as Loss2; here, we use a method commonly used in the art to measure the line loss of the fifth cable 3;

Step S3 , referring to FIG. 2 , separate the first cable 13 from the first connection point 112 , separate the third cable 15 from the second signal interface 122 , and take out the second cable 14 After that, connect the two ends of the second cable 14 to the end of the first cable 13 and the second signal interface 122 respectively. In this way, the first cable 13 and the second signal interface 122 can be measured. Sum of line loss of cable 14, and record the measurement result as Loss3;

In step S4, the line loss of the radio frequency test tool is calculated according to the following formula: Loss=Loss1-Loss2-Loss3, where Loss is the line loss of the radio frequency test tool. In fact, the line loss Loss of the RF test tool is the line loss between the device under test 2 and the coupling board 1111 , the line loss of the third cable 15 , and the line loss of the fourth cable The sum of the three.

In the step S1, the device under test 2 includes a PCB board, and an antenna and an antenna matching element mounted on the PCB board. The device under test 2 is fixed in the second installation cavity on the fixing table 111 .

In the step S2, the fifth cable 3 includes a radio frequency wire and a radio frequency terminal. Of course, the radio frequency wire and the radio frequency terminal are matched with the antenna.

By using the calibration method provided in this embodiment, it is only necessary to measure the line loss Loss1 of the entire loop, the line loss Loss2 of the fifth cable, and the sum of the line losses of the first cable and the second cable through the above steps. Loss3, and then calculate according to the formula to obtain the line loss Loss of the RF test tooling, and realize the rapid calibration of the RF test tooling. The entire calibration process is simple and easy to implement. Most importantly, it does not need to use a gold machine, which can greatly improve the efficiency of RF test tool calibration and greatly reduce costs.

In addition, the fixing table 111 is provided with an adjacent first installation cavity and a second installation cavity, and the coupling plate 1111 and the device under test 2 are respectively fixed in the first installation cavity and the second installation cavity. In the installation cavity, it can be ensured that the relative position of the coupling plate 1111 and the device under test 2 will not change during the measurement process, so as to ensure accurate and reliable measurement results.

In some other embodiments, the RF test instrument 12 may also adopt other models, as long as an instrument with RF transmit/receive functions is selected.

The embodiments of the invention have been described above in conjunction with the accompanying drawings, but the invention is not limited to the above-mentioned specific embodiments. The above-mentioned specific embodiments are only illustrative rather than restrictive. Under the inspiration of the invention, many forms can be made without departing from the scope of the invention and the protection scope of the claims, which are all within the protection of the invention.

Claims (6)

1. The calibration method of the radio frequency test tool is characterized by comprising a test instrument (12) and a shielding box (11), wherein the test instrument (12) is provided with a first signal interface (121) and a second signal interface (122), a fixed table (111) is arranged in the shielding box (11), a coupling plate (1111) is installed on the fixed table (111), a first connection point (112) and a second connection point (113) are arranged on the side wall of the shielding box (11), the second signal interface (122) is connected with the second connection point (113) through a third cable (15), and the second connection point (113) is connected with the coupling plate (1111) through a fourth cable (16); the calibration method comprises the following steps:

step S1, mounting a device to be measured (2) on the fixed station (111), connecting the first signal interface (121) with the first connecting point (112) by the first cable (13), connecting a fifth cable (3) at one end of the device to be measured (2), connecting the fifth cable (3) with the first cable (13) by a second cable (14), measuring the line Loss of the whole loop, and recording the measurement result as Loss 1;

step S2, measuring the line Loss of the fifth cable (3), and recording the measurement result as Loss 2;

step S3, separating the first cable (13) from the first connection point (112), separating the third cable (15) from the second signal interface (122), taking out the second cable (14), connecting two ends of the second cable (14) to the terminal of the first cable (13) and the second signal interface (122), respectively, measuring the sum of the line losses of the first cable (13) and the second cable (14), and recording the measurement result as Loss 3;

step S4, calculating the line loss of the radio frequency test tool according to the following formula: the Loss is 1-Loss2-Loss3, wherein the Loss is the line Loss of the radio frequency test tool.

2. The calibration method of the radio frequency test tool according to claim 1, wherein the device under test (2) comprises a PCB, and an antenna matching element attached to the PCB.

3. The calibration method of the radio frequency test tool according to claim 1, wherein the test instrument (12) is an RF test instrument (12).

4. The calibration method of the radio frequency test tool according to claim 1, wherein a first mounting cavity is formed in the solid stage, and the coupling plate (1111) is fixed in the first mounting cavity.

5. The calibration method of the radio frequency test tool according to claim 1, wherein a second mounting cavity is arranged on the solid-state table; in the step S1, the step of "mounting the device under test (2) on the fixed stage (111)" is to fix the device under test (2) in the second mounting chamber.

6. The calibration method of the radio frequency test tool according to claim 1, wherein the fifth cable (3) comprises a radio frequency wire and a radio frequency terminal.

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