Circuit and working method for improving electrostatic immunity of a router using a radio frequency transformer

Abstract

The present application relates to the field of radio frequency technology and the field of wireless communication technology, and provides a circuit and working method for improving electrostatic immunity of a router by using a radio frequency transformer. The circuit comprises a main control modulation and demodulation module and a PAM power amplifier module, the main control modulation and demodulation module and the PAM power amplifier module are connected to a radio frequency transformer module, an isolation power supply and a digital signal isolator, and the secondary side of the radio frequency transformer module, the isolation power supply, the digital signal isolator and the PAM power amplifier module are connected to the same ground terminal. The present application uses the radio frequency transformer to isolate the ground of the power amplifier / low noise amplifier and the antenna from the main control modulation and demodulation circuit, and the ground planes are not directly connected, so that the electrostatic from the antenna port into the equipment to affect the main control digital device is avoided, and the whole machine is prevented from being shut down.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of radio frequency technology and the field of wireless communication technology, in particular to a circuit and working method for improving the electrostatic immunity of a router by using a radio frequency transformer. BACKGROUND

[0002] The statements in this section merely provide background information related to the present application and do not necessarily constitute the prior art.

[0003] The currently commonly used radio frequency port device is mostly of the charge leakage type, such as transient diode TVS and electrostatic discharge tube ESD. Such devices can leak electrostatic energy from the radio frequency line to the reference ground plane of the PCBA system, thereby protecting active devices such as radio frequency switches, power amplifiers, and low-noise amplifiers. However, static electricity can still flow through the PCBA board along the internal reference ground plane and then be discharged to the ground, forming a common-mode interference.

[0004] Most devices containing antenna radio frequency ports have a radio frequency coaxial signal return path directly connected to the internal reference ground of the whole machine. This is the most traditional and direct connection method, which is most conducive to the conduction of radio frequency signals. However, this most common method also has certain drawbacks: when the antenna return path (such as a split antenna SMA seat) is affected by static electricity, the interference signal will be directly conducted to the lower part of the digital device through the reference plane. Especially when the digital circuit of the main control part has a high speed, a low logic level, and a complex structure (such as an external DDR memory chip), the system is prone to crash. For industrial and other scenes with high reliability requirements, such crashes caused by static electricity can cause significant losses. SUMMARY

[0005] To solve the problems of the prior art, the present application provides a circuit and working method for improving the electrostatic immunity of a router by using a radio frequency transformer. The power amplifier / low-noise amplifier and the antenna ground are isolated from the main control modulation and demodulation circuit by using a radio frequency transformer, and the ground planes are not directly connected, thereby avoiding the entry of static electricity from the antenna port into the device and affecting the main control digital device, and causing the whole machine to crash.

[0006] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0007] The first aspect of the present application provides a circuit for improving the electrostatic immunity of a router by using a radio frequency transformer.

[0008] The circuit for improving electrostatic immunity of a router by using a radio frequency transformer comprises a main control modulation and demodulation module and a PAM power amplifier module, both of which are connected to a radio frequency transformer module, an isolated power supply and a digital signal isolator, and the secondary side of the radio frequency transformer module, the isolated power supply, the digital signal isolator and the PAM power amplifier module are connected to the same ground terminal.

[0009] Further, the main control modulation and demodulation module is connected to the primary side of the radio frequency transformer module through a direct current biasing and direct current isolation circuit module, and the secondary side of the radio frequency transformer module is connected to the PAM power amplifier module.

[0010] Further, the direct current biasing and direct current isolation circuit module comprises at least one direct current biasing and direct current isolation circuit.

[0011] Further, the radio frequency transformer module comprises at least one radio frequency transformer.

[0012] Further, the PAM power amplifier module comprises at least one.

[0013] Further, when there are multiple PAM power amplifier modules, each PAM power amplifier module has the same structure; or, each PAM power amplifier module has different structures; or, some PAM power amplifier modules have the same structure and some PAM power amplifier modules have different structures.

[0014] Further, when one direct current biasing and direct current isolation circuit, two radio frequency transformers and one PAM power amplifier module are used, one end of the direct current biasing and direct current isolation circuit is connected to the main control modulation and demodulation module, the other end is connected to the primary side of the first radio frequency transformer, the secondary side of the first radio frequency transformer is connected to the input terminal of the PAM power amplifier module; the output terminal of the PAM power amplifier module is connected to the secondary side of the second radio frequency transformer, and the primary side of the second radio frequency transformer is connected to the main control modulation and demodulation module.

[0015] Further, when one direct current biasing and direct current isolation circuit, three radio frequency transformers and two PAM power amplifier modules are used, one end of the direct current biasing and direct current isolation circuit is connected to the main control modulation and demodulation module, the other end is connected to the primary side of the first radio frequency transformer, the secondary side of the first radio frequency transformer is connected to the input terminal of the first PAM power amplifier module; the output terminal of the first PAM power amplifier module is connected to the secondary side of the second radio frequency transformer, the primary side of the second radio frequency transformer is connected to the main control modulation and demodulation module; the primary side of the third radio frequency transformer is connected to the main control modulation and demodulation module, and the secondary side of the third radio frequency transformer is connected to the second PAM power amplifier module.

[0016] Further, when two DC biasing and DC blocking circuits, four RF transformers and two PAM power amplifier modules are used, one end of the first DC biasing and DC blocking circuit is connected to the master modulation and demodulation module, and the other end is connected to the primary side of the first RF transformer, the secondary side of the first RF transformer is connected to the input end of the first PAM power amplifier module; the output end of the first PAM power amplifier module is connected to the secondary side of the second RF transformer, and the primary side of the second RF transformer is connected to the master modulation and demodulation module; one end of the second DC biasing and DC blocking circuit is connected to the master modulation and demodulation module, and the other end is connected to the primary side of the third RF transformer, the secondary side of the third RF transformer is connected to the input end of the second PAM power amplifier module; the output end of the second PAM power amplifier module is connected to the secondary side of the fourth RF transformer, and the primary side of the fourth RF transformer is connected to the master modulation and demodulation module.

[0017] Further, a power isolation device is used to isolate the digital signal isolator from the front end of the PAM power amplifier module.

[0018] The second aspect of the present application provides a circuit working method for improving the electrostatic immunity of a router by using an RF transformer.

[0019] The second aspect of the present application provides a circuit working method for improving the electrostatic immunity of a router by using an RF transformer.

[0020] The RF signal emitted by the master modulation and demodulation module is transmitted to the power amplifier through the RF transformer, amplified by the power amplifier, and then radiated to the space through the antenna;

[0021] The signal captured by the antenna is transmitted to the RF transformer through the low noise amplifier, and then transmitted to the master modulation and demodulation module through the power amplifier for data demodulation.

[0022] Compared with the prior art, the present application has the following advantages:

[0023] The present application uses an RF transformer to isolate the ground of the power amplifier / low noise amplifier and the antenna from the master modulation and demodulation circuit, and the ground planes are not directly connected, which avoids the influence of static electricity entering the device from the antenna port on the master digital device, and causes the whole machine to be down.

[0024] The present application combines a power isolation module to realize the isolation of the digital device and the front end of the RF amplifier, and to reduce the influence of the RF transformer insertion loss on the RF circuit as much as possible. For electrostatic interference, the reference ground planes on both sides are not directly connected to suppress the transmission of interference signals along the ground plane. BRIEF DESCRIPTION OF DRAWINGS

[0025] The accompanying drawings, which form a part of this specification, are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification. The embodiments of the application, and of the individual features, are described in this specification to explain the application. The application is not limited in scope by the detailed description of its embodiments.

[0026] Figure 1 A conventional router circuit diagram shown in the present application;

[0027] Figure 2 A structure diagram of a circuit for improving electrostatic immunity of a router using a radio frequency transformer shown in the present application;

[0028] Figure 3 A structure diagram of a circuit for improving electrostatic immunity of a router using a radio frequency transformer shown in the present application;

[0029] Figure 4 A structure diagram of a circuit for improving electrostatic immunity of a router using a radio frequency transformer shown in the present application. DETAILED DESCRIPTION

[0030] The application will be further described below in conjunction with the drawings and embodiments.

[0031] It should be noted that the following detailed description is exemplary in nature and is intended to provide further description of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0032] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0033] In the present application, the terms such as "connected", "connection" and the like should be understood broadly, which means that it can be fixed connection, integral connection or detachable connection; it can be direct connection or indirect connection through intermediate medium. For the relevant scientific research or technical personnel in the art, the specific meaning of the above terms in the present application can be determined according to the specific circumstances, and it should not be understood as a limitation of the present application.

[0034] The embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0035] Example 1

[0036] Embodiment 1 of the present invention provides a circuit for improving the electrostatic discharge immunity of a router using an RF transformer, comprising: a main control modulation and demodulation module and a PAM power amplifier module. The main control modulation and demodulation module and the PAM power amplifier module are both connected to the RF transformer module, an isolation power supply and a digital signal isolator. The secondary side of the RF transformer module, the isolation power supply, the digital signal isolator and the PAM power amplifier module are connected to the same ground terminal.

[0037] The main control modulation and demodulation module is connected to the primary side of the RF transformer module through a DC bias and DC blocking circuit module, and the secondary side of the RF transformer module is connected to the PAM power amplifier module.

[0038] The DC bias and DC blocking circuit module includes at least one DC bias and DC blocking circuit; specifically, the RF transformer module includes at least one RF transformer; and the PAM power amplifier module has at least one component.

[0039] When there are multiple PAM power amplifier modules, each PAM power amplifier module has the same structure; or, each PAM power amplifier module has a different structure; or, some PAM power amplifier modules have the same structure; and some PAM power amplifier modules have a different structure.

[0040] like Figure 2 As shown, when using a DC bias and DC blocking circuit, two RF transformers, and a PAM power amplifier module, one end of the DC bias and DC blocking circuit is connected to the main control modulation and demodulation module, and the other end is connected to the primary side of the first RF transformer. The secondary side of the first RF transformer is connected to the input terminal of the PAM power amplifier module. The output terminal of the PAM power amplifier module is connected to the secondary side of the second RF transformer, and the primary side of the second RF transformer is connected to the main control modulation and demodulation module.

[0041] like Figure 3 As shown, when using a DC bias and DC blocking circuit, three RF transformers, and two PAM power amplifier modules, one end of the DC bias and DC blocking circuit is connected to the main control modulation and demodulation module, and the other end is connected to the primary side of the first RF transformer. The secondary side of the first RF transformer is connected to the input terminal of the first PAM power amplifier module. The output terminal of the first PAM power amplifier module is connected to the secondary side of the second RF transformer, and the primary side of the second RF transformer is connected to the main control modulation and demodulation module. The primary side of the third RF transformer is connected to the main control modulation and demodulation module, and the secondary side of the third RF transformer is connected to the second PAM power amplifier module.

[0042] like Figure 4As shown, when two DC bias and DC isolation circuits, four RF transformers and two PAM power amplifier modules are adopted, one end of the first DC bias and DC isolation circuit is connected to the master control modulation and demodulation module, and the other end is connected to the primary side of the first RF transformer, the secondary side of the first RF transformer is connected to the input end of the first PAM power amplifier module; the output end of the first PAM power amplifier module is connected to the secondary side of the second RF transformer, and the primary side of the second RF transformer is connected to the master control modulation and demodulation module; one end of the second DC bias and DC isolation circuit is connected to the master control modulation and demodulation module, and the other end is connected to the primary side of the third RF transformer, the secondary side of the third RF transformer is connected to the input end of the second PAM power amplifier module; the output end of the second PAM power amplifier module is connected to the secondary side of the fourth RF transformer, and the primary side of the fourth RF transformer is connected to the master control modulation and demodulation module.

[0043] The above Figure 2 、 Figure 3 、 Figure 4 Only three kinds of technical solutions of the present application can be realized, and should not be understood as a limitation of the present application. When other quantities of DC bias and DC isolation circuits, RF transformers and PAM power amplifier modules are adopted, they also belong to the protection scope of the present application.

[0044] Figure 1 is a conventional router circuit diagram, Figures 2-4 is a router circuit diagram using RF transformer isolation, as Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 As shown, the LC balun in the conventional router is replaced by an isolated RF transformer (if the master control chip modulation and demodulation part output is a single-ended signal, an RF transformer is added on the RF link). The reference ground planes of the two parts of the master control to the isolated RF transformer and the isolated RF transformer to the antenna are separated. An isolated power supply is added to supply power to the PAM power amplifier module (which can be an integrated power amplifier module, or a combination of power amplifiers, low noise amplifiers, RF switches, etc.). In addition, a digital signal isolation device is also needed to isolate the control signal of the RF device. After the above modifications to the circuit, the ground plane of the PAM module can be grounded using a resistor-capacitor device (here, it refers to the equipment that needs to be grounded, and the equipment that does not need to be grounded can not have this step), and further, the static and other interference signals are introduced into the ground.

[0045] Generally, the purpose of the radio frequency transformer is to realize the balance-unbalance (also called double-end and single-end conversion, the isolated radio frequency transformer) or impedance conversion (isolated radio frequency transformer). However, when the frequency is greater than 1000MHz, the insertion loss of such devices is large, and such devices are basically not used under the condition of greater than 1000MHz. The scheme of the embodiment is to combine the power isolator and the digital signal isolator to realize the isolation of the master control part (including the digital circuit, the modulation and demodulation circuit) and the PAM power amplifier module front end, and to reduce the influence of the insertion loss of the radio frequency transformer or the isolated radio frequency transformer on the radio frequency circuit as much as possible. For electrostatic interference, the characteristics of the isolation of such devices are mainly used, so that the two sides of the reference ground plane are not directly connected, and the transmission of the interference signal along the ground plane is suppressed.

[0046] The digital signal isolator and the PAM power amplifier module front end are isolated by using the power isolator.

[0047] Specifically, the master control modulation and demodulation module includes a controller, a modulation circuit and a demodulation circuit. The modulation circuit is used to load the effective signal of the transmission information to a certain carrier, and the demodulation circuit is used to demodulate the effective signal of the transmission information from the modulated signal. The modulation circuit and the demodulation circuit can be realized by using the existing circuit structure.

[0048] The direct current biasing and direct current isolation circuit module is generally a component attached to the modulation and demodulation circuit. It can be used or not used according to the different master control modulation and demodulation circuits. The main function is that the direct current biasing circuit provides power for the drive amplifier that may exist in the modulation and demodulation circuit part, and the function of the direct current isolation circuit is to avoid the short circuit caused by the direct current flowing through the radio frequency transformer. The direct current biasing circuit and the direct current isolation circuit can be realized by using the existing circuit structure.

[0049] Embodiment 2

[0050] The embodiment 2 of the application provides a circuit working method for improving the electrostatic interference immunity of a router by using a radio frequency transformer.

[0051] The radio frequency signal emitted by the modulation circuit is transmitted to the power amplifier through the isolated radio frequency transformer, is amplified by the power amplifier, and is radiated to the space through the antenna. Similarly, the signal captured by the antenna is transmitted to the power amplifier through the low-noise amplifier and the isolated radio frequency transformer, and finally is transmitted to the demodulation circuit to realize data demodulation. The two parts share the same link. In addition, the isolated power module only supplies power to the front-end amplification circuit and the active switch.

[0052] The above merely provides the preferred embodiments of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the principles and technical scope of the present application shall fall into the scope of the present application.

Claims

1. A circuit for improving electrostatic immunity of a router using a radio frequency transformer, characterized in that, The application relates to a PAM power amplifier module and a main control modulation and demodulation module. The isolated power supply supplies power for the PAM power amplifier module, and the digital signal isolator isolates the control signal of the radio frequency device; the isolated power supply and the digital signal isolator are combined to realize the front-end isolation of the main control modulation and demodulation module and the PAM power amplifier module, so that the two reference ground planes are not directly connected, and the transmission of interference signals along the ground plane is inhibited. The main control modulation and demodulation module is connected with the primary side of the radio frequency transformer module through a direct current biasing and direct current isolation circuit module, and the secondary side of the radio frequency transformer module is connected with the PAM power amplifier module. The direct current biasing and direct current isolation circuit module comprises at least one direct current biasing and direct current isolation circuit. The radio frequency transformer module comprises at least one radio frequency transformer.

2. The circuit for improving electrostatic immunity of a router using a radio frequency transformer of claim 1, wherein, The PAM power amplifier module comprises at least one.

3. The circuit for improving electrostatic immunity of a router using a radio frequency transformer of claim 1, wherein, When the PAM power amplifier module comprises multiple PAM power amplifier modules, the structures of the PAM power amplifier modules are the same, different or partially the same and partially different.

4. The circuit for improving electrostatic immunity of a router using a radio frequency transformer of claim 1, wherein, When one direct current biasing and direct current isolation circuit, two radio frequency transformers and one PAM power amplifier module are adopted, one end of the direct current biasing and direct current isolation circuit is connected with the main control modulation and demodulation module, the other end is connected with the primary side of the first radio frequency transformer, the secondary side of the first radio frequency transformer is connected with the input end of the PAM power amplifier module, the output end of the PAM power amplifier module is connected with the secondary side of the second radio frequency transformer, and the primary side of the second radio frequency transformer is connected with the main control modulation and demodulation module.

5. The circuit for improving electrostatic immunity of a router using a radio frequency transformer of claim 1, wherein, When one direct current biasing and direct current isolation circuit, three radio frequency transformers and two PAM power amplifier modules are adopted, one end of the direct current biasing and direct current isolation circuit is connected with the main control modulation and demodulation module, the other end is connected with the primary side of the first radio frequency transformer, the secondary side of the first radio frequency transformer is connected with the input end of the first PAM power amplifier module, the output end of the first PAM power amplifier module is connected with the secondary side of the second radio frequency transformer, the primary side of the second radio frequency transformer is connected with the main control modulation and demodulation module, the primary side of the third radio frequency transformer is connected with the main control modulation and demodulation module, and the secondary side of the third radio frequency transformer is connected with the second PAM power amplifier module.

6. The circuit for improving electrostatic immunity of a router using a radio frequency transformer of claim 1, wherein, ​ 7. The circuit for improving electrostatic immunity of a router using a radio frequency transformer of claim 1, wherein, When two DC bias and DC isolation circuit, four RF transformers and two PAM power amplifier module are used, one end of the first DC bias and DC isolation circuit is connected to the master modulation and demodulation module, and the other end is connected to the primary side of the first RF transformer, the secondary side of the first RF transformer is connected to the input end of the first PAM power amplifier module; the output end of the first PAM power amplifier module is connected to the secondary side of the second RF transformer, the primary side of the second RF transformer is connected to the master modulation and demodulation module; one end of the second DC bias and DC isolation circuit is connected to the master modulation and demodulation module, and the other end is connected to the primary side of the third RF transformer, the secondary side of the third RF transformer is connected to the input end of the second PAM power amplifier module; the output end of the second PAM power amplifier module is connected to the secondary side of the fourth RF transformer, and the primary side of the fourth RF transformer is connected to the master modulation and demodulation module.

8. A method of operating a circuit for improving electrostatic immunity of a router using a radio frequency transformer, characterized in that, The circuit for improving the electrostatic immunity of the router by using the RF transformer according to any one of claims 1-7 comprises: The RF signal emitted by the master modulation and demodulation module is transmitted to the power amplifier through the RF transformer, amplified by the power amplifier, and then radiated to the space through the antenna; The signal captured by the antenna is transmitted to the RF transformer through the low noise amplifier, and then transmitted to the master modulation and demodulation module through the power amplifier for data demodulation.

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