Power supply noise test system

Abstract

A power supply noise test system is used for detecting power supply noise of a product with a radio frequency antenna and comprises a first antenna, the first antenna is arranged in the product to be tested and integrated on a circuit board of the product to be tested, a radio frequency connector is arranged on the circuit board, and the first antenna is connected with the radio frequency connector; the second antenna is located outside a shell of a product to be tested, the second antenna is connected with the radio frequency connector through a radio frequency test line, and both the first antenna and the second antenna are radio frequency antennas; a near-field probe; the power supply noise test analysis unit comprises a low noise amplifier, an attenuator and a spectrum analyzer which are connected in sequence; the radio frequency test line and the near-field probe are connected with the low-noise amplifier through feeder lines. According to the invention, different antennas can be utilized to detect local or external power supply noise in a product and power supply noise in a radio frequency band and a full frequency band, and the detection precision and sensitivity are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of signal testing, and in particular relates to a power supply noise testing system for an electronic product with a radio frequency antenna. Background Art

[0002] Power supply is a commonly used power supply device in electronic products. Power supply will generate noise during operation. Unqualified noise problems will directly affect the product's EMC and EMI test requirements. Especially for electronic products with RF antennas such as routers and concentrators, the radiation generated by power supply noise will directly interfere with the antenna's transmission and reception, reduce the product's receiving sensitivity and transmission power, and further affect the product's communication rate and communication distance. Therefore, the test indicators of power supply noise are more sensitive.

[0003] Traditional power supply noise test systems mostly use an oscilloscope in conjunction with a near-field probe to test power supply noise, such as the power supply ripple and noise auxiliary test system disclosed in the Chinese invention patent application with application number 2020110173784. This test system uses a near-field probe to detect noise in various parts of the product, but the layout of components on the internal circuit board of the product is intricate and the space is cramped. When using a near-field probe for detection, there are some locations where the near-field probe cannot be placed, and the noise source and the interfered working frequency band cannot be accurately located. The power supply noise can only be roughly detected, and it is difficult to accurately determine whether a specific area or a specific antenna working frequency band is interfered with by power supply noise radiation, resulting in low sensitivity and poor test accuracy. Moreover, relying on probes and oscilloscopes makes the power supply noise test process inflexible and difficult to meet the testing needs of highly integrated RF products. Summary of the invention

[0004] The object of the present invention is to provide a power supply noise testing system which can improve detection accuracy and measurement sensitivity.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A power supply noise test system is used to perform a power supply noise test on a product with a radio frequency antenna, comprising: a first antenna, the first antenna is built into the product to be tested and integrated on a circuit board of the product to be tested, a radio frequency connector is provided on the circuit board, and the first antenna is connected to the radio frequency connector; a second antenna, the second antenna is located outside the shell of the product to be tested, the second antenna is connected to the radio frequency connector through a radio frequency test line, and the first antenna and the second antenna are both radio frequency antennas; a near-field probe; a power supply noise test and analysis unit, the power supply noise test and analysis unit comprises a low-noise amplifier, an attenuator and a spectrum analyzer connected in sequence; the radio frequency test line and the near-field probe are connected to the low-noise amplifier through a feeder.

[0007] Furthermore, the RF connector has a first RF port, a second RF port, a third RF port and a switching switch, and the switching switch is used to switch the connectivity relationship between the first RF port, the second RF port and the third RF port; the first RF port is a signal input port, the second RF port and the third RF port are signal output ports, the first RF port and the second RF port are connected by default, and when the RF test line is inserted into the RF connector, the connection between the first RF port and the second RF port is disconnected through the switching switch, and the first RF port and the third RF port are connected.

[0008] Furthermore, the first antenna is a PCB antenna, a patch antenna or a spring antenna.

[0009] Furthermore, a radio frequency signal source is provided on the circuit board of the product to be tested, and the product to be tested has a first radio frequency working mode and a second radio frequency working mode; in the first radio frequency working mode, the radio frequency signal source is connected to the first radio frequency port, the first antenna is connected to the second radio frequency port, the first radio frequency port and the second radio frequency port are connected, and the first radio frequency port and the third radio frequency port are disconnected; the working path of the first radio frequency working mode is: radio frequency signal source→radio frequency connector→first antenna; in the second radio frequency working mode, the radio frequency signal source is connected to the first radio frequency port, the second antenna is connected to the third radio frequency port through the radio frequency signal line, the connection between the first radio frequency port and the second radio frequency port is disconnected, and the first radio frequency port and the third radio frequency port are connected; the working path of the second radio frequency working mode is: radio frequency signal source→radio frequency connector→radio frequency test line→second antenna.

[0010] Further, it includes a first power supply noise test mode and a second power supply noise test mode; in the first power supply noise test mode, the first antenna is connected to the first RF port, the RF test line is connected to the third RF port, the RF test line is connected to the low noise amplifier through a feeder, the connection between the first RF port and the second RF port is disconnected, and the first RF port and the third RF port are connected, and the working path of the first power supply noise test mode is: first antenna→RF connector→RF test line→power supply noise test analysis unit; in the second power supply noise test mode, the second antenna is connected to the RF test line, the RF test line is connected to the low noise amplifier through a feeder, and the working path of the second power supply noise test mode is: second antenna→RF test line→power supply noise test analysis unit; or, the near-field probe is connected to the low-noise amplifier through a feeder, and the working path of the second power supply noise test mode is: near-field probe→power supply noise test analysis unit.

[0011] It can be known from the above technical scheme that the present invention utilizes the radio frequency antenna built into the product to be tested and the external antenna and near-field probe outside the product to be tested. The built-in antenna can be used to detect the power supply noise of the radio frequency working frequency band, and the external antenna or near-field probe can be used to detect the power supply noise of other interference frequency bands and the full frequency band of the product to be tested. The built-in antenna can accurately locate the power supply noise inside the product, overcoming the problem that the near-field probe is not convenient to place and cannot be accurately located in a small space. It has the advantages of simple structure, convenient use, low price, high test accuracy and wide test range, and can be directly designed and used in mass-produced products, with high flexibility and accuracy. Moreover, the built-in antenna and the external antenna can be flexibly switched, and the built-in antenna or the external antenna can be arbitrarily selected for use according to the needs of different signal radiation or reception in the workplace, and the cost is low.

[0012] The present invention also provides a power supply noise test system for a dual RF antenna product, wherein the dual RF antenna product comprises a shell, a first antenna, a second antenna, a RF connector, a RF signal source and a circuit board, wherein the circuit board is arranged in the shell, the RF connector and the RF signal source are arranged on the circuit board, the first antenna is a built-in antenna integrated on the circuit board, and the second antenna is an external antenna; the first antenna is connected to the RF connector through an internal circuit of the circuit board, and the second antenna is connected to the RF connector through a RF test line; the power supply noise test system comprises the first antenna, the second antenna, a near-field probe and a power supply noise test analysis unit, and the power supply noise test analysis unit comprises a low-noise amplifier, an attenuator and a spectrum analyzer connected in sequence; the RF test line and the near-field probe are connected to the low-noise amplifier through a feeder.

[0013] In the power supply noise test system as described above, further, the RF connector has a first RF port, a second RF port, a third RF port and a switch, and the switch is used to switch the connectivity between the first RF port, the second RF port and the third RF port. Specifically, the first RF port is a signal input port, the second RF port and the third RF port are signal output ports, the first RF port and the second RF port are connected by default, and when the RF test line is inserted into the RF connector, the connection between the first RF port and the second RF port is disconnected through the switch, and the first RF port and the third RF port are connected.

[0014] It can be seen from the above technical solutions that the present invention aims at the power supply noise test of dual RF antenna products, and makes an improved design for the antenna switching structure of dual RF antenna products. It uses an RF connector that is easy to switch the connection relationship and connects the built-in and external antennas. The built-in antenna and the external antenna can be easily switched according to the needs, which improves the scene application ability of the RF antenna product. It is not necessary to decide in advance which antenna to install before production, but it can be switched at will according to the signal strength after production. Moreover, on the basis of realizing the dual RF working path function of the product, the power supply noise of the RF working frequency band can be detected by the built-in antenna through the RF connector, and the power supply noise of other interference frequency bands and the full frequency band of the product to be tested can be detected by an external antenna or a near-field probe. The built-in antenna can accurately locate the internal power supply noise of the product, which overcomes the problem that the near-field probe is not easy to place and cannot be accurately located in a small space. It has the advantages of simple structure, easy use, low price, high test accuracy and wide test range. The switching structure of the internal and external antennas of the present invention can be directly designed and used in mass-produced products, has high flexibility and accuracy, and can arbitrarily select the internal antenna or the external antenna for use according to the requirements of different signal radiation or reception in the workplace. It is inexpensive and convenient for noise data collection during product production testing, and for switching of the internal and external antennas of the product in radio frequency working scenarios.

[0015] In the power supply noise testing system as described above, further, the first antenna is a PCB antenna, a patch antenna, or a spring antenna.

[0016] As described above, the power supply noise test system, further, the dual RF antenna product has a first RF working mode and a second RF working mode; in the first RF working mode, the RF signal source is connected to the first RF port, the first antenna is connected to the second RF port, the first RF port and the second RF port are connected, and the first RF port and the third RF port are disconnected; the working path of the first RF working mode is: RF signal source→RF connector→first antenna; in the second RF working mode, the RF signal source is connected to the first RF port, the second antenna is connected to the third RF port through the RF signal line, the connection between the first RF port and the second RF port is disconnected, and the first RF port and the third RF port are connected; the working path of the second RF working mode is: RF signal source→RF connector→RF test line→second antenna.

[0017] The power supply noise test system as described above further includes a first power supply noise test mode and a second power supply noise test mode; in the first power supply noise test mode, the first antenna is connected to the first RF port, the RF test line is connected to the third RF port, the RF test line is connected to the low noise amplifier through a feeder, the connection between the first RF port and the second RF port is disconnected, and the first RF port and the third RF port are connected, and the working path of the first power supply noise test mode is: first antenna→RF connector→RF test line→power supply noise test analysis unit; in the second power supply noise test mode, the second antenna is connected to the RF test line, the RF test line is connected to the low noise amplifier through a feeder, and the working path of the second power supply noise test mode is: second antenna→RF test line→power supply noise test analysis unit; or, the near-field probe is connected to the low noise amplifier through a feeder, and the working path of the second power supply noise test mode is: near-field probe→power supply noise test analysis unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 It is a structural block diagram of a power supply noise testing system according to an embodiment of the present invention;

[0020] Figure 2 A schematic diagram of a power supply noise testing system according to an embodiment of the present invention;

[0021] Figure 3 A schematic diagram of the working path of the first radio frequency working mode of the product under test;

[0022] Figure 4 A schematic diagram of the connection of the RF port of the RF connector in the first RF working mode of the product to be tested;

[0023] Figure 5 A schematic diagram of the working path of the second radio frequency working mode of the product under test;

[0024] Figure 6 It is a schematic diagram of the connection of the RF port of the RF connector in the second RF working mode of the product to be tested;

[0025] Figure 7 A schematic diagram of a working path of a first power supply noise test mode according to an embodiment of the present invention;

[0026] Figure 8This is a schematic diagram of the connection of the RF port of the RF connector in the first power supply noise test mode of an embodiment of the present invention;

[0027] Fig. 9 Schematic diagram of the working path of the second power supply noise test mode according to an embodiment of the present invention.

[0028] The specific implementation modes of the present invention are further described in detail below with reference to the accompanying drawings. DETAILED DESCRIPTION

[0029] The present invention is described in detail below in conjunction with the accompanying drawings. When describing the embodiments of the present invention in detail, for the convenience of explanation, the drawings representing the device structure will not be partially enlarged according to the general proportion, and the schematic diagram is only an example, which should not limit the scope of protection of the present invention. It should be noted that the drawings are simplified in form and use non-precise proportions, which are only used to facilitate and clearly assist in explaining the purpose of the embodiments of the present invention. At the same time, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated; the terms "positive", "negative", "bottom", "upper", "lower", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0030] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it 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 it can be indirectly connected through an intermediate medium, it can also be the internal connection of two elements, it can be a wireless connection, or it can be a wired connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] like Figure 1 and Figure 2 As shown, the power supply noise test system of this embodiment includes: a first antenna 1, a second antenna 2, a near-field probe 3, a low-noise amplifier 4, an attenuator 5 and a spectrum analyzer 6. Among them, the first antenna 1 is an antenna built into the product under test, and the first antenna 1 can be integrated on the circuit board of the product under test ( Figure 1The components in the dotted box are components arranged on the circuit board). The second antenna 2 is an external antenna, and the second antenna 2 is arranged outside the shell of the product under test. The first antenna 1 and the second antenna 2 are both RF antennas, and their function in the product under test is to transmit the RF signal generated by the RF signal source. Specifically, the first antenna 1 can be an antenna that can be built into the product under test, such as a PCB antenna, a patch antenna, a spring antenna, etc.

[0032] The first antenna 1 of this embodiment is connected to the RF connector 7 arranged on the circuit board, and the second antenna 2 is connected to the RF connector 7 through the RF test line 9. The RF test line 9 and the near-field probe 3 are connected to the low-noise amplifier 4 through the feeder 11. The low-noise amplifier 4 is connected to the attenuator 5 through the coaxial connecting line 12, and the attenuator 5 is connected to the spectrum analyzer 6. The low-noise amplifier 4, the attenuator 5 and the spectrum analyzer 6 constitute a power supply noise test and analysis unit 10. In a specific application, the power supply noise test and analysis unit 10 may also include devices for signal processing such as a power amplifier module and a filter module.

[0033] The RF connector 7 of this embodiment is an RF connector with three RF ports (the first RF port 7a, the second RF port 7b and the third RF port 7c), and the RF connector 7 has a switching switch inside, such as a spring switch, for switching the connectivity between different RF ports. Among the three RF ports of the RF connector 7, the first RF port 7a is a signal input port, and the second RF port 7b and the third RF port 7c are signal output ports. The first RF port 7a and the second RF port 7b are connected by default. When the RF test line 9 is inserted into the RF connector 7, it will touch the switching switch inside the RF connector 7, so that the connection between the first RF port 7a and the second RF port 7b is disconnected, and the connection is automatically switched to the first RF port 7a and the third RF port 7c, and the RF test line 9 is connected to the third RF port 7c. With this structure of the RF connector, the switching between the external RF antenna and the built-in RF antenna can be simply and quickly realized by inserting the RF test line 9. In specific applications, the RF connector 7 can adopt the third-generation RF test socket ECT818011998 of the electric connection ECT.

[0034] A radio frequency signal source 8 is also provided on the circuit board of the product to be tested, and the radio frequency signal source 8 can be located on the same circuit board as the radio frequency connector 7, or on a different circuit board. The radio frequency signal generated by the radio frequency signal source 8 is transmitted through the first antenna 1 or the second antenna 2. Among them, the radio frequency signal source 8→radio frequency connector 7→first antenna 1 is the first radio frequency working path of the product to be tested. The radio frequency signal source 8→radio frequency connector 7→radio frequency test line 9→second antenna 2 is the second radio frequency working path of the product to be tested. In the radio frequency working mode, the radio frequency signal generated by the radio frequency signal source 8 can be input through the first radio frequency port 7a, output from the second radio frequency port 7b, and transmitted by the first antenna 1, or the radio frequency signal generated by the radio frequency signal source 8 can be input through the first radio frequency port 7a, output from the third radio frequency port 7c, and transmitted by the second antenna 2.

[0035] In the prior art, the built-in antenna and the external antenna of the product to be tested are usually switched by a radio frequency switch or a reserved short-circuited zero-ohm resistor. The use of a radio frequency switch requires software control, which is relatively complicated, and the use of a short-circuited zero-ohm resistor is not suitable for large-scale changes in products, so it has low flexibility and production feasibility. The present invention uses a radio frequency connector with three radio frequency ports and can automatically switch the connection relationship of the radio frequency ports by inserting a radio frequency test line, so that the switching of the antenna is simpler, and the flexibility of switching the built-in antenna and the external antenna of the product to be tested is improved.

[0036] Reference Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 , the two RF working modes of the product to be tested are explained.

[0037] like Figure 2 , Figure 3 and Figure 4 As shown, the working path of the first RF working mode is: RF signal source 8→RF connector 7→first antenna 1. In this RF working mode, the RF signal source 8 is connected to the first RF port 7a of the RF connector 7, and the RF signal source 8 inputs the RF signal into the first RF port 7a through the impedance line on the circuit board. The first RF port 7a and the second RF port 7b are connected by default, the first antenna 1 is connected to the second RF port 7b of the RF connector 7, and the RF signal is output from the second RF port 7b. The built-in first antenna 1 sends the RF signal outward in the form of electromagnetic waves.

[0038] like Figure 2 , Figure 5 and Figure 6As shown, the working path of the second RF working mode is: RF signal source 8→RF connector 7→RF test line 9→second antenna 2. In this RF working mode, the RF signal source 8 is connected to the first RF port 7a of the RF connector 7, and the RF signal source 8 inputs the RF signal to the first RF port 7a through the impedance line on the circuit board, and the second antenna 2 is connected to the third RF port 7c of the RF connector 7 through the RF test line 9. After the RF test line 9 is connected, the connection between the first RF port 7a and the second RF port 7b of the RF connector 7 is disconnected, and the first RF port 7a and the third RF port 7c are switched to be connected, and the RF signal is output from the third RF port 7c, and the second antenna 2 sends the RF signal outward in the form of electromagnetic waves, realizing the flexible switching between the internal antenna and the external antenna.

[0039] The test system of the present invention has two power supply noise test paths, wherein the first antenna 1→RF connector 7→RF test line 9→feeder 11→low noise amplifier 4→coaxial connection line 12→attenuator 5→spectrum analyzer 6 is the first power supply noise test path. The near-field probe 3 (or the second antenna 2→RF test line 9)→feeder 11→low noise amplifier 4→coaxial connection line 12→attenuator 5→spectrum analyzer 6 is the second power supply noise test path.

[0040] The present invention uses the first antenna 1 built into the product to be tested as a power supply noise probe to test the internal power supply noise of the product to be tested. Since the first antenna 1 is integrated on the circuit board of the product to be tested, it will not be affected by the layout of components on the circuit board, and the noise can be accurately located, solving the problem of inaccurate positioning caused by the inability to place near-field probes in some locations inside the product to be tested. Moreover, the present invention can also use the near-field probe 3 or the second antenna 2 to detect the power supply noise of other interference frequency bands and the full frequency band of the product.

[0041] Reference Figure 2 , Figure 7 , Figure 8 and Fig. 9 The power supply noise test system of the present invention can implement the following two power supply noise test modes: a first power supply noise test mode and a second power supply noise test mode.

[0042] like Figure 2 , Figure 7 and Figure 8As shown, the working path of the first power supply noise test mode is: first antenna 1→RF connector 7→RF test line 9→power supply noise test analysis unit 10. In this working mode, since the RF test line 9 is plugged into the RF connector 7, the first RF port 7a and the second RF port 7b of the RF connector 7 are disconnected, and the first RF port 7a and the third RF port 7c are connected. Since the first RF port 7a is a signal input port, at this time, it is only necessary to turn the RF connector 7 on the circuit board so that the first RF port 7a and the first antenna 1 are connected. The noise generated by the power supply is received by the first antenna 1 and connected to the low noise amplifier 4 through the RF test line 9 and the feeder 11. The low noise amplifier 4 amplifies the weak power supply noise signal received by the first antenna 1 and transmits it to the attenuator 5 and the spectrum analyzer 6 to realize the image power supply noise analysis. The attenuator 5 is used to prevent the noise power from being too large to damage the spectrum analyzer 6. The first power supply noise test mode directly uses the first antenna 1 built into the product to be tested to detect power supply noise, which not only simplifies the system structure, saves space, and reduces test costs, but also can accurately locate the power supply noise in the RF working frequency band that is easily received by the built-in antenna, with high accuracy and sensitivity.

[0043] like Figure 2 and Fig. 9 As shown, the working path of the second power supply noise test mode is: the second antenna 2 or near-field probe 3 → power supply noise test analysis unit 10. In this working mode, the second antenna 2 or near-field probe 3 receives the noise signal generated by the power supply of the product to be tested, and is connected to the low-noise amplifier 4 through the feeder 12. After the noise signal is amplified by the low-noise amplifier 4, it is transmitted to the attenuator 5 and the spectrum analyzer 6 to realize the graphical power supply noise analysis, which is suitable for the weak noise analysis of the RF power supply. The use of an external antenna or near-field probe meets the richness of power supply noise detection. The built-in antenna analyzes the power supply noise of the fixed RF working frequency band. The external antenna or near-field probe can detect the power supply noise at other frequency points that need to be analyzed. By matching the full-band antenna or omnidirectional antenna, the entire noise-affected frequency band and the power supply noise impact in all directions of the RF product can also be detected.

[0044] The present invention cleverly utilizes the first antenna built into the product and the RF connector with multiple RF ports that can automatically switch the connection relationship. It can not only realize the arbitrary switching of different antennas in the RF working mode, but also use different antennas to detect the power supply noise of the local or external part of the product to be tested and the RF frequency band and the full frequency band in the noise test mode. The use of built-in antennas has the advantages of simple structure, space saving and low cost. The use of external antennas can meet the different requirements of antennas in various application occasions. By matching with the RF connecting line, the built-in antenna can be directly switched to the external antenna. The two do not conflict with each other and have high flexibility.

[0045] The present invention uses a spectrum analyzer to implement the graphical spectrum analysis of antenna noise, which is more suitable for the analysis of weak noise of radio frequency power supply than the traditional test probe plus oscilloscope method.

[0046] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A power supply noise test system, used for testing power supply noise of products with radio frequency antennas, characterized in that: include: a first antenna, wherein the first antenna is built into the product to be tested and integrated on a circuit board of the product to be tested, a radio frequency connector is provided on the circuit board, and the first antenna is connected to the radio frequency connector; A second antenna, the second antenna is located outside the housing of the product to be tested, the second antenna is connected to the RF connector through an RF test line, and the first antenna and the second antenna are both RF antennas; Near field probe; A power supply noise test and analysis unit comprises a low noise amplifier, an attenuator and a spectrum analyzer connected in sequence; the radio frequency test line and the near field probe are connected to the low noise amplifier via a feeder line.

2. The power supply noise testing system as claimed in claim 1, characterized in that: The RF connector has a first RF port, a second RF port, a third RF port and a switch, and the switch is used to switch the connectivity between the first RF port, the second RF port and the third RF port; The first RF port is a signal input port, the second RF port and the third RF port are signal output ports, the first RF port and the second RF port are connected by default, and when the RF test line is inserted into the RF connector, the connection between the first RF port and the second RF port is disconnected through the switching switch, and the first RF port and the third RF port are connected.

3. The power supply noise testing system as claimed in claim 1, characterized in that: The first antenna is a PCB antenna, a patch antenna or a spring antenna.

4. The power supply noise testing system as claimed in claim 2, characterized in that: A radio frequency signal source is provided on the circuit board of the product to be tested, and the product to be tested has a first radio frequency working mode and a second radio frequency working mode; In the first RF working mode, the RF signal source is connected to the first RF port, the first antenna is connected to the second RF port, the first RF port is connected to the second RF port, the first RF port is connected to the second RF port, and the first RF port is disconnected from the third RF port; the working path of the first RF working mode is: RF signal source→RF connector→first antenna; In the second RF working mode, the RF signal source is connected to the first RF port, the second antenna is connected to the third RF port through the RF signal line, the connection between the first RF port and the second RF port is disconnected, and the first RF port and the third RF port are connected; the working path of the second RF working mode is: RF signal source→RF connector→RF test line→second antenna.

5. The power supply noise testing system as claimed in claim 1, characterized in that: including a first power supply noise test mode and a second power supply noise test mode; In the first power supply noise test mode, the first antenna is connected to the first RF port, the RF test line is connected to the third RF port, the RF test line is connected to the low noise amplifier through a feeder, the connection between the first RF port and the second RF port is disconnected, and the first RF port and the third RF port are connected, and the working path of the first power supply noise test mode is: first antenna→RF connector→RF test line→power supply noise test analysis unit; In the second power supply noise test mode, the second antenna is connected to the RF test line, the RF test line is connected to the low noise amplifier through a feeder, and the working path of the second power supply noise test mode is: second antenna→RF test line→power supply noise test analysis unit; or, the near-field probe is connected to the low noise amplifier through a feeder, and the working path of the second power supply noise test mode is: near-field probe→power supply noise test analysis unit.

6. A power supply noise test system for a dual RF antenna product, characterized in that: The dual RF antenna product includes a housing, a first antenna, a second antenna, a RF connector, a RF signal source and a circuit board. The circuit board is arranged in the housing, the RF connector and the RF signal source are arranged on the circuit board, the first antenna is a built-in antenna integrated on the circuit board, and the second antenna is an external antenna. The first antenna is connected to the RF connector via a circuit on a circuit board, and the second antenna is connected to the RF connector via a RF test line; The power supply noise test system includes the first antenna, the second antenna, a near-field probe and a power supply noise test and analysis unit. The power supply noise test and analysis unit includes a low-noise amplifier, an attenuator and a spectrum analyzer connected in sequence; the RF test line and the near-field probe are connected to the low-noise amplifier through a feeder.

7. The power supply noise testing system as claimed in claim 6, characterized in that: The RF connector has a first RF port, a second RF port, a third RF port and a switch, and the switch is used to switch the connectivity between the first RF port, the second RF port and the third RF port.

8. The power supply noise testing system as claimed in claim 6, characterized in that: The first antenna is a PCB antenna, a patch antenna or a spring antenna.

9. The power supply noise testing system as claimed in claim 7, characterized in that: The dual radio frequency antenna product has a first radio frequency working mode and a second radio frequency working mode; In the first RF working mode, the RF signal source is connected to the first RF port, the first antenna is connected to the second RF port, the first RF port is connected to the second RF port, the first RF port is connected to the second RF port, and the first RF port is disconnected from the third RF port; the working path of the first RF working mode is: RF signal source→RF connector→first antenna; In the second RF working mode, the RF signal source is connected to the first RF port, the second antenna is connected to the third RF port through the RF signal line, the connection between the first RF port and the second RF port is disconnected, and the first RF port and the third RF port are connected; the working path of the second RF working mode is: RF signal source→RF connector→RF test line→second antenna.

10. The power supply noise testing system as claimed in claim 6, characterized in that: including a first power supply noise test mode and a second power supply noise test mode; In the first power supply noise test mode, the first antenna is connected to the first RF port, the RF test line is connected to the third RF port, the RF test line is connected to the low noise amplifier through a feeder, the connection between the first RF port and the second RF port is disconnected, and the first RF port and the third RF port are connected, and the working path of the first power supply noise test mode is: first antenna→RF connector→RF test line→power supply noise test analysis unit; In the second power supply noise test mode, the second antenna is connected to the RF test line, the RF test line is connected to the low noise amplifier through a feeder, and the working path of the second power supply noise test mode is: second antenna→RF test line→power supply noise test analysis unit; or, the near-field probe is connected to the low noise amplifier through a feeder, and the working path of the second power supply noise test mode is: near-field probe→power supply noise test analysis unit.

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