Test circuit board

Abstract

The utility model provides a test circuit board, which comprises a bus circuit and four test circuits communicated with the bus circuit respectively, the four test circuits are connected with four single-pole four-throw radio frequency tuning switches respectively, and the four single-pole four-throw radio frequency tuning switches are connected with the bus circuit. The four single-pole four-throw radio frequency tuning switches can conduct a first output path, a second output path, a third output path and a fourth output path respectively, and are connected to a radio frequency antenna through the conducted output paths respectively; the bus circuit is used for supplying power to the test circuits and providing a control signal, and the four test circuits are respectively used for testing off-state capacitance of an output path correspondingly conducted by the single-pole four-throw radio frequency tuning switch connected with the test circuits according to the control signal. The test circuit board provided by the utility model can quickly calibrate the single-pole four-throw radio frequency tuning switch, is small in test influence, and is beneficial to improving the accuracy of a radio frequency antenna performance test process.

Description

Technical Field

[0001] This utility model applies to the field of radio frequency circuits, and in particular relates to a test circuit board. Background Technology

[0002] In the field of wireless communication, radio frequency (RF) tuning switches are among the most important components in the 4G and 5G eras, especially for mobile phone communication. As technology advances, the number and frequency bands that mobile phone antennas need to support increase. Due to design complexity, more and more aperture tuners need to be used on individual antennas to optimize the overall antenna performance across various frequency bands. To overcome the problems caused by reduced antenna area and efficiency, aperture tuning is the primary method, and combinations of aperture and impedance tuning are also used to support the ever-expanding frequency range, especially the 5G band.

[0003] The existing approach involves connecting a single-pole four-throw (SP4T) tuner switch between the antenna and the tuning assembly to tune the antenna to different frequency bands. The antenna is connected to a tuning capacitor via one test port of the SP4T, while the other three ports are open. This grounding path helps eliminate resonance caused by capacitance generated at the switch-off ports. R is used in this configuration. on The on-state resistance between the antenna and the test port is represented by C. off This refers to the disconnect capacitance between the simulated antenna and the other three ports. Related data indicates that reducing R... on This can improve the efficiency of inductively tuned and capacitively tuned antennas by several decibels (dB), thus significantly impacting the overall RF performance of mobile phones using such antennas. Reducing C off It can achieve a similar effect.

[0004] Antenna design inevitably requires connecting the antenna to a single-pole four-throw tuner switch via a circuit board for performance testing. However, in actual testing, the test circuit board used is not compatible with C... off The accuracy of this played a crucial role, due to the C of the test circuit board itself. off The capacitance is relatively large, typically in the picofarad (pF) range. For a single-pole four-throw tuner switch, it's around 100 fF. Even slight fluctuations during the testing process can affect the accuracy of the test circuit board. Therefore, reducing the capacitance of the test circuit board itself is crucial. off It is also quite crucial during the testing process. Utility Model Content

[0005] This invention provides a test circuit board, which aims to solve the technical problem that the open-state capacitor is inaccurate during the testing of existing single-pole four-throw tuner switches due to the influence of the test circuit.

[0006] To solve the above-mentioned technical problems, this utility model provides a test circuit board, which includes a bus circuit and four test circuits connected to the bus circuit. The four test circuits are respectively connected to four single-pole four-throw RF tuning switches. The four single-pole four-throw RF tuning switches can respectively conduct their first output path, second output path, third output path, and fourth output path, and are respectively connected to an RF antenna through their conducted output paths. The bus circuit is used to supply power to the test circuits and provide control signals. The four test circuits are respectively used to test the open state capacitance of the corresponding conducted output path of the single-pole four-throw RF tuning switch connected to them according to the control signals.

[0007] Furthermore, the test circuit board is a multi-layer circuit board structure formed by stacking, including a first metal layer, a second metal layer, a third metal layer and a fourth metal layer stacked in sequence; the first metal layer is hollowed out with four test interfaces corresponding to the four test circuits, and the test interfaces are respectively used to connect the four single-pole four-throw radio frequency tuning switches; the second metal layer, the third metal layer and the fourth metal layer are all provided with hollowed-out structures at the hollowed-out positions corresponding to the test interfaces.

[0008] Furthermore, the first metal layer, the second metal layer, the third metal layer, and the fourth metal layer are all provided with vias, and an electrical connection is formed between adjacent metal layers through the vias.

[0009] Furthermore, the fourth metal layer is provided with radio frequency signal wiring for connecting the single-pole four-throw radio frequency tuning switch and the radio frequency antenna, and the third metal layer is provided with control signal wiring for connecting the bus circuit and the test circuit. The radio frequency signal wiring and the control signal wiring are perpendicular to each other in the stacking direction of the test circuit board, and the wiring spacing is greater than 3 times the line width.

[0010] Furthermore, the test circuit includes a power supply port, an input / output power supply port, a serial digital port, a serial clock port, and a pin port; the bus circuit is connected to each of the test circuits respectively, and supplies power to each of the test circuits through their respective power supply ports and input / output power supply ports, and provides control signals to each of the test circuits through their respective serial digital ports, serial clock ports, and pin ports.

[0011] Furthermore, the test circuit board is made of Rogers4350B material.

[0012] The beneficial effect achieved by this utility model is that it proposes a test circuit board that facilitates testing the open-state capacitance of a single-pole four-throw RF tuner switch. This test circuit board, by testing the open-state capacitance of different conduction paths of the single-pole four-throw RF tuner switch, is conducive to the rapid calibration of the single-pole four-throw RF tuner switch, and has little impact on the test data of the single-pole four-throw RF tuner switch, which helps to improve the accuracy of the RF antenna performance testing process. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of the test circuit board provided in this embodiment of the utility model;

[0014] Figure 2 This is a schematic diagram of the first metal layer structure of the test circuit board provided in this embodiment of the present invention;

[0015] Figure 3 This is a schematic diagram of the second metal layer structure of the test circuit board provided in this embodiment of the utility model;

[0016] Figure 4 This is a schematic diagram of the third metal layer structure of the test circuit board provided in this embodiment of the utility model;

[0017] Figure 5 This is a schematic diagram of the fourth metal layer structure of the test circuit board provided in this embodiment of the present invention;

[0018] Figure 6 This is a schematic diagram of the structure of the test circuit board provided in this embodiment of the utility model, and a schematic diagram of the circuit structure in use. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0020] For details, please refer to Figure 1 , Figure 1This is a schematic diagram of the structure of the test circuit board provided in this embodiment of the utility model. The test circuit board 100 includes a bus circuit 101 and four test circuits 102 respectively connected to the bus circuit. The four test circuits 102 are respectively connected to four different single-pole four-throw RF tuning switches. The four single-pole four-throw RF tuning switches can respectively turn on their first output path RF1, second output path RF2, third output path RF3, and fourth output path RF4, and are respectively connected to the RF antenna SMA through their turned output paths. The bus circuit 101 is used to supply power to the test circuits 102 and provide control signals. The four test circuits 102 are respectively used to test the open state capacitance of the corresponding turned output path of the single-pole four-throw RF tuning switch connected to them according to the control signals.

[0021] During the design and testing of the RF antenna, the disconnected state capacitance obtained by the test circuit 102 designed according to the embodiment of this utility model is further tested to determine the background noise and path loss of the test circuit board when the single-pole four-throw RF tuning switch under test is not installed. Then, through calibration, the influence of fixture parasitic parameters on the test circuit board during the testing and design process is eliminated.

[0022] Specifically, the test circuit board is a multilayer circuit board structure formed by stacking, including a first metal layer M1, a second metal layer M2, a third metal layer M3, and a fourth metal layer M4; please refer to the following for details. Figures 2 to 5 These are schematic diagrams of the structure of the first metal layer M1, the second metal layer M2, the third metal layer M3, and the fourth metal layer M4 in the test circuit board provided in this embodiment of the present invention. The first metal layer M1 is hollowed out and has four test interfaces 200 corresponding to the four test circuits, which are respectively used to connect the four single-pole four-throw RF tuning switches. The second metal layer M2, the third metal layer M3, and the fourth metal layer M4 are all provided with hollowed-out structures 300 at the hollowed-out positions of the test interfaces 200. The hollowed-out structures 300 in the horizontal direction help to reduce the stray capacitance of the test circuit board itself.

[0023] In this embodiment of the invention, in order to further reduce the stray capacitance of the test circuit board itself, such as... Figures 2 to 5 As shown, in the vertical direction, the first metal layer M1, the second metal layer M2, the third metal layer M3 and the fourth metal layer M4 are all provided with vias. Adjacent metal layers are electrically connected through the vias. Furthermore, the vertically connected vias can be provided with a hollow structure 400 depending on the feasibility of their location.

[0024] Please refer to the following for details. Figure 4 and Figure 5The fourth metal layer M4 has RF signal wiring 500 for connecting the single-pole four-throw RF tuning switch and the RF antenna. The third metal layer M3 has control signal wiring 600 for connecting the bus circuit 101 and the test circuit 102. The RF signal wiring 500 and the control signal wiring 600 are perpendicular to each other in the stacking direction of the test circuit board, and the wiring spacing is greater than 3 times the line width. The test circuit board is made of Rogers 4350B material. This design helps to minimize the test path and reduce path loss.

[0025] Furthermore, please refer to Figure 6 , Figure 6 This is a schematic diagram of the circuit structure of the test circuit board in use according to an embodiment of the present invention. The test circuit 102 includes a power supply port VDD, an input / output power supply port VIO, a serial digital port SDATA, a serial clock port SCLK, and a pin port ID0; the bus circuit 101 is connected to each of the test circuits 102 ( Figure 6 The circuits are connected as a, b, c, and d, and each test circuit 102 is powered through its respective power supply port VDD and input / output power supply port VIO. Control signals are also provided to each test circuit 102 through its respective serial digital port SDATA, serial clock port SCLK, and pin port ID0. During use, the four single-pole four-throw RF tuning switches ( Figure 6 A, B, C, and D are respectively connected to their first output path RF1, second output path RF2, third output path RF3, and fourth output path RF4, and are respectively connected to the RF antenna SMA through their output paths. By using different connected output paths, the corresponding test circuit can quickly test the open state capacitance of the single-pole four-throw RF tuning switch.

[0026] The beneficial effect achieved by this utility model is that it proposes a test circuit board that facilitates testing the open-state capacitance of a single-pole four-throw RF tuner switch. This test circuit board, by testing the open-state capacitance of different conduction paths of the single-pole four-throw RF tuner switch, is conducive to the rapid calibration of the single-pole four-throw RF tuner switch, and has little impact on the test data of the single-pole four-throw RF tuner switch, which helps to improve the accuracy of the RF antenna performance testing process.

[0027] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0028] The embodiments of the present utility model have been described above with reference to the accompanying drawings. The disclosed embodiments are merely preferred embodiments of the present utility model. However, the present utility model is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many equivalent changes under the guidance of the present utility model without departing from the spirit and scope of the claims. All such changes are within the protection scope of the present utility model.

Claims

1. A test circuit board, characterized in that, The test circuit board includes a bus circuit and four test circuits connected to the bus circuit. The four test circuits are respectively connected to four single-pole four-throw RF tuning switches. The four single-pole four-throw RF tuning switches can respectively conduct their first output path, second output path, third output path, and fourth output path, and are respectively connected to the RF antenna through their conducted output paths. The bus circuit is used to supply power to the test circuits and provide control signals. The four test circuits are respectively used to test the open state capacitance of the corresponding conducted output path of the single-pole four-throw RF tuning switch connected to them according to the control signals.

2. The test circuit board according to claim 1, characterized in that, The test circuit board is a multi-layer circuit board structure formed by stacking, including a first metal layer, a second metal layer, a third metal layer and a fourth metal layer stacked in sequence; the first metal layer has four test interfaces corresponding to the four test circuits, and the test interfaces are respectively used to connect the four single-pole four-throw radio frequency tuning switches; the second metal layer, the third metal layer and the fourth metal layer are all provided with cutout structures at the cutout positions corresponding to the test interfaces.

3. The test circuit board according to claim 2, characterized in that, The first metal layer, the second metal layer, the third metal layer, and the fourth metal layer are all provided with vias, and an electrical connection is formed between adjacent metal layers through the vias.

4. The test circuit board according to claim 2, characterized in that, The fourth metal layer is provided with radio frequency signal wiring for connecting the single-pole four-throw radio frequency tuning switch and the radio frequency antenna. The third metal layer is provided with control signal wiring for connecting the bus circuit and the test circuit. The radio frequency signal wiring and the control signal wiring are perpendicular to each other in the stacking direction of the test circuit board, and the wiring spacing is greater than 3 times the line width.

5. The test circuit board according to claim 1, characterized in that, The test circuit includes a power supply port, an input / output power supply port, a serial digital port, a serial clock port, and a pin port; the bus circuit is connected to each of the test circuits respectively, and supplies power to each of the test circuits through their respective power supply ports and input / output power supply ports, and provides control signals to each of the test circuits through their respective serial digital ports, serial clock ports, and pin ports.

6. The test circuit board according to claim 1, characterized in that, The test circuit board is made of Rogers4350B material.

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