Electromagnetic pulse protection circuit and radio frequency transceiver system

Abstract

The application relates to the field of electromagnetic protection, in particular to an electromagnetic pulse protection circuit and a radio frequency transceiving system. The electromagnetic pulse protection circuit comprises a radio frequency coupling capacitor C3, a first LC branch and a second LC branch. Two series LC branches and the radio frequency coupling capacitor C3 form a basic Pi-type circuit, the two LC branches are connected through a stub STUB between connection nodes, a bidirectional reciprocal constant impedance circuit structure is formed, a strong electromagnetic pulse discharge channel is formed between the stub STUB and the ground, and any device is added between the stub STUB and the ground, so that the impedance between the first connection node K1 and the second connection node K2 is not affected, thereby a constant impedance electromagnetic pulse protection circuit is formed. If a failure occurs in the electromagnetic pulse protection and suppression device in the circuit, whether it is an open circuit or a short circuit, the impedance of the whole circuit is not affected, so that the normal transmission of the radio frequency signal is not affected.

Description

Technical Field

[0001] This application relates to the field of electromagnetic protection, and in particular to an electromagnetic pulse protection circuit and a radio frequency transceiver system. Background Technology

[0002] With the widespread application of various wireless equipment and facilities in engineering fields such as industrial and agricultural production, scientific research, outer space exploration, national defense construction, and homeland security, various wireless transceiver systems are placed in complex electromagnetic environments. In particular, when the antennas and coaxial feeders of wireless transceiver system equipment are exposed to the outside of the equipment, they are highly susceptible to interference from various transient electromagnetic pulses in the complex electromagnetic environment. These transient electromagnetic pulses can be introduced into the transceiver system through the antennas and feeders, causing damage to critical and sensitive equipment within the system, thereby affecting the normal operation of the wireless equipment and facilities.

[0003] When an electromagnetic pulse (EMP) protection device malfunctions, causing a failure in the protection circuit itself, the circuit impedance often changes, leading to system failure. If the failure is solely due to a faulty protection device, but the circuit impedance remains unchanged, the system's normal function will not be affected, thus avoiding practical engineering problems caused by abnormal protection system operation. Summary of the Invention

[0004] To address the problem that faults in current electromagnetic pulse protection devices can alter circuit impedance and impair the system's ability to transmit radio frequency (RF) signals, this application provides an electromagnetic pulse protection circuit and an RF transceiver system.

[0005] Firstly, this application provides an electromagnetic pulse protection circuit:

[0006] The electromagnetic pulse protection circuit includes a radio frequency coupling capacitor C3, a first LC branch, and a second LC branch; one end of the radio frequency coupling capacitor C3 is electrically connected to the radio frequency input terminal J1, and the other end of the radio frequency coupling capacitor C3 is electrically connected to the radio frequency output terminal J2.

[0007] The first LC branch includes a first inductor L1 and a first capacitor C1 connected in series; the inductor end of the first LC branch is electrically connected to a second connection node K2, which is located between the RF coupling capacitor C3 and the RF output terminal J2; the capacitor end of the first LC branch is grounded.

[0008] The second LC branch includes a second inductor L2 and a second capacitor C2 connected in series; the inductor end of the second LC branch is electrically connected to the first connection node K1, which is located between the RF coupling capacitor C3 and the RF input terminal J1; the capacitor end of the second LC branch is grounded.

[0009] The fourth connection node K4, located between the first inductor L1 and the first capacitor C1, is connected to the third connection node K3, located between the second inductor L2 and the second capacitor C2, through a short stub to form a constant impedance circuit structure; and an electromagnetic pulse protection and suppression device is electrically connected between the short stub and ground to form a strong electromagnetic pulse discharge path.

[0010] Optionally, the electromagnetic pulse protection and suppression device is a voltage-current switching device.

[0011] Optionally, the voltage and current switching device includes one of a gas discharge tube, a transient voltage suppression diode, and a PIN diode.

[0012] Optionally, the electromagnetic pulse protection and suppression device includes a short-circuit stub.

[0013] Optionally, the first inductor L1 and the second inductor L2 have the same specifications; the first capacitor C1 and the second capacitor C2 have the same specifications.

[0014] Optionally, the first capacitor C1 or the second capacitor C2 in the electromagnetic pulse protection circuit can be removed and replaced with a short-circuited short-circuit wire.

[0015] Secondly, this application provides a radio frequency transceiver system:

[0016] The radio frequency transceiver system includes an electromagnetic pulse protection circuit as described in any of the above.

[0017] This application includes at least the following beneficial technical effects:

[0018] 1. Two series-connected LC branches and RF coupling capacitor C3 form a basic Π-type circuit. The connection nodes of the two LC branches are connected by a short stub, forming a bidirectional reciprocal constant impedance circuit structure. The short stub and ground form a strong electromagnetic pulse discharge channel. Adding any device between the short stub and ground will not affect the impedance between the first connection node K1 and the second connection node K2, thus constructing an electromagnetic pulse protection constant impedance circuit. If the electromagnetic pulse protection and suppression device used in this circuit fails, whether it is an open circuit or a short circuit, it will not affect the impedance of the entire circuit, thus not affecting the normal transmission of RF signals. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of an electromagnetic pulse protection circuit structure in an embodiment of this application;

[0020] Figure 2 This is a schematic diagram of another electromagnetic pulse protection circuit structure in an embodiment of this application;

[0021] Figure 3 This is a block diagram of a radio frequency transceiver system according to an embodiment of this application. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0023] The terminology used in the following embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to include the plural expressions as well, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this application refers to and includes any or all possible combinations of one or more of the listed items. The term “exemplary” means “serving as an example, embodiment, or illustration,” and any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. The terms “first” and “second” are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as “first” or “second” may explicitly or implicitly include one or more of that feature, and in the description of the embodiments of this application, unless otherwise stated, “a plurality” means two or more.

[0024] To ensure that the transceiver systems of wireless equipment and facilities can operate continuously in extremely complex and harsh electromagnetic environments and effectively protect against various harmful transient electromagnetic pulses, this application provides an electromagnetic pulse protection circuit based on the actual usage of typical wireless equipment and the need for protection against strong transient electromagnetic pulses.

[0025] refer to Figure 1An electromagnetic pulse protection circuit includes a radio frequency coupling capacitor C3, a first LC branch, and a second LC branch. One end of the radio frequency coupling capacitor C3 is electrically connected to a radio frequency input terminal J1, and the other end of the radio frequency coupling capacitor C3 is electrically connected to a radio frequency output terminal J2. The first LC branch includes a first inductor L1 and a first capacitor C1 connected in series. The inductor end of the first LC branch is electrically connected to a second connection node K2, wherein the second connection node K2 is located between the radio frequency coupling capacitor C3 and the radio frequency output terminal J2. The capacitor end of the first LC branch is grounded. The second LC branch includes a second inductor L2 and a second capacitor C2 connected in series. The inductor end of the second LC branch is electrically connected to a first connection node K1, wherein the first connection node K1 is located between the radio frequency coupling capacitor C3 and the radio frequency input terminal J1. The capacitor end of the second LC branch is grounded. A fourth connection node K4 located between the first inductor L1 and the first capacitor C1 is connected to a third connection node K3 located between the second inductor L2 and the second capacitor C2 via a short wire.

[0026] In this embodiment, L1 and L2 are inductive devices, C1, C2, and C3 are capacitive devices, and STUB is a resistive device. The two-stage series filter LC circuit consists of a first inductor L1, a first capacitor C1, a second inductor L2, and a second capacitor C2, which, combined with the symmetrically distributed RF coupling capacitor C3, form a Π-type high-pass filter circuit. The RF coupling capacitor C3, together with the first inductor L1, the first capacitor C1, the second inductor L2, and the second capacitor C2, forms a parallel resonant response circuit. The two LC branch connection nodes are connected by a stub STUB, forming a constant impedance RF matching network and a frequency selection circuit. The stub STUB and ground form a strong electromagnetic pulse discharge channel. Adding any device between the stub STUB and ground will not affect the impedance Z0 between the first connection node K1 and the second connection node K2, that is, the impedance between the RF input terminal J1 and the RF output terminal J2 is constant. In this embodiment, the circuit impedance Z0 mainly depends on the values ​​of the two series LC branches and the RF coupling capacitor C3, and is unrelated to the electromagnetic pulse protection and suppression device used in the circuit. Even if the electromagnetic pulse protection and suppression device fails, it will not affect the overall circuit impedance, thus constructing an electromagnetic pulse protection constant impedance circuit.

[0027] In this embodiment, the first inductor L1 and the second inductor L2 in the two LC branches, together with the stub, form a transmission channel for strong electromagnetic pulses (such as lightning electromagnetic pulses) with a slow leading edge (hereinafter referred to as "slow edge") on the order of microseconds (µs). The surge pulse voltage induced by the lightning electromagnetic pulse forms a short circuit to ground, and the surge pulse current forms a discharge path to ground. The RF coupling capacitor C3 isolates the slow edge pulse, thus achieving the protection against strong electromagnetic pulses. Simultaneously, it ensures the system's normal transmission and processing of RF signals when the electromagnetic pulse protection and suppression device fails. The two ends of this circuit (RF input J1 and RF output J2) are directly connected to the RF transmission line, facilitating its use in various transceiver devices and providing comprehensive protection against transient strong electromagnetic pulses for critical and sensitive components.

[0028] refer to Figure 2 In an optional embodiment of this application, a constant impedance circuit structure is formed. Specifically, an electromagnetic pulse protection and suppression device can be electrically connected between the short-circuit stub and the ground to form a strong electromagnetic pulse discharge circuit structure.

[0029] The electromagnetic pulse protection circuit provided in this application embodiment can be used as a slow-edge strong transient electromagnetic pulse suppression circuit. C3 couples the radio frequency signal, J1-C3-J2 is the radio frequency signal coupling transmission channel, and J1-L1-STUB1-L2-J2 is the slow-edge strong transient electromagnetic pulse transmission channel. A protection device with strong electromagnetic pulse response characteristics, such as a gas discharge tube, transient voltage suppression diode, or PIN diode, is connected between the line at node K2-SUTB-node K4 and ground. These devices are in an open-circuit state when not in operation. When a transient slow-edge strong electromagnetic pulse interferes and the amplitude reaches the corresponding activation voltage, the protection device will activate and suppress the strong electromagnetic pulse. When these devices fail or malfunction, an open circuit or short circuit is formed, which will not affect the impedance of the circuit, thus demonstrating the constant impedance characteristic and function, thereby forming a slow-edge strong transient electromagnetic pulse suppression circuit.

[0030] In optional embodiments of this application, the electromagnetic pulse protection and suppression device can be a short-circuit device, such as a short-circuit stub or an air-core inductor. This directly discharges the surge overcurrent induced by the slow-edge transient strong electromagnetic pulse to ground and limits the induced surge overvoltage to a lower potential, thereby effectively protecting the transceiver system from interference and damage caused by slow-edge transient strong electromagnetic pulses (such as lightning electromagnetic pulses). The two-stage high-pass LC filter and the intermediate parallel resonant response circuit together form a symmetrical reciprocal circuit structure, which can work synergistically to effectively exert a comprehensive suppression and protection effect against various fast-edge and slow-edge strong electromagnetic pulses.

[0031] The electromagnetic pulse protection circuit provided in this application has an inertial function. For example, adding an open-circuit device or a short-circuit device between the stub STUB and ground has no effect on the impedance between J1 and J2, and has no effect on the RF performance parameters of the entire circuit. It has a bidirectional reciprocal constant impedance characteristic at the port.

[0032] In an optional embodiment of this application, the first inductor L1 and the second inductor L2 have the same specifications; the first capacitor C1 and the second capacitor C2 have the same specifications. By using a symmetrical circuit structure to cancel out the stray capacitance and stray inductance of the LC branch, it is beneficial to extend the operating bandwidth of the transceiver system and improve its performance.

[0033] In an optional embodiment of this application, the electromagnetic pulse protection circuit described above can be flexibly reconfigured as needed to meet certain individual requirements.

[0034] For example, the first capacitor C1 or the second capacitor C2 in the electromagnetic pulse protection circuit can be removed and replaced by a short-circuited short-circuit wire; that is, L1&C1&L2 or L2&C2&L1 can be retained to form a symmetrical reciprocal strong transient electromagnetic pulse suppression circuit.

[0035] For example, removing any one of L1, L2, L1&C1, or L2&C2 on either side can create a unidirectional multi-type strong transient electromagnetic pulse integrated protection circuit.

[0036] The electromagnetic pulse protection circuit provided in this application has a bidirectional reciprocal constant impedance characteristic at the port, which solves the problem of degradation of radio frequency performance parameters after traditional electromagnetic pulse protection and suppression devices are connected to radio frequency circuits. This solution can easily reduce the distributed parameters within the radio frequency and microwave frequency range, achieve impedance matching of the radio frequency network, and improve the reliability of the comprehensive protection circuit. It can have good radio frequency performance and environmental temperature adaptability within the effective operating bandwidth. It can simultaneously complete the suppression and absorption functions of various strong transient electromagnetic pulses and the effective transmission of radio frequency coaxial signals, solve the compatibility problem of various strong transient electromagnetic pulse protection circuits, and achieve significant comprehensive protection effect against various strong transient electromagnetic pulses.

[0037] Based on the above embodiments, this embodiment also provides a radio frequency transceiver system.

[0038] refer to Figure 3 The radio frequency transceiver system includes the electromagnetic pulse protection circuit described above.

[0039] It should be understood that the radio frequency (RF) transceiver system is a key component of a wireless communication system. It is responsible for converting digital signals into RF signals suitable for wireless transmission and for converting the RF signals back into digital signals at the receiving end. The RF transceiver system consists of two main parts: an RF receiver and an RF transmitter. The transmitter includes a signal source, modulator, amplifier, and antenna, and is responsible for converting the baseband signal into an RF signal and transmitting it. The receiver includes an antenna, low-noise amplifier, demodulator, and signal processor, and is responsible for recovering the original baseband signal from the RF signal.

[0040] The above description of the embodiments is only used to provide a detailed introduction to the technical solutions of this application. However, the description of the above embodiments is only for the purpose of helping to understand the methods and core ideas of this application, and should not be construed as a limitation of this application. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the protection scope of this application.

Claims

1. An electromagnetic pulse protection circuit, characterized in that, The electromagnetic pulse protection circuit includes an RF coupling capacitor C3, a first LC branch, and a second LC branch, used to protect against microsecond-level slow-edge strong electromagnetic pulses, and possesses bidirectional reciprocity at the ports; one end of the RF coupling capacitor C3 is electrically connected to the RF input terminal J1, and the other end of the RF coupling capacitor C3 is electrically connected to the RF output terminal J2, and the RF coupling capacitor C3 provides isolation for the slow-edge strong electromagnetic pulse; the first LC branch includes a first inductor L1 and a first capacitor C1 connected in series; the inductor end of the first LC branch is electrically connected to a second connection node K2, which is located between the RF coupling capacitor C3 and the RF output terminal J2; the capacitor end of the first LC branch is grounded, and the first LC branch and the RF coupling capacitor C3 form a parallel resonant response circuit; the second LC branch includes a second inductor L2 and a second capacitor C2 connected in series; the inductor end of the second LC branch is electrically connected to a first connection node K1, which is located between the RF coupling capacitor C3 and the RF input terminal J1; the first ... first LC branch includes a second inductor L2 and a second capacitor C2, which are connected in series; the second LC branch includes a second inductor L2 and a second capacitor C2, which are connected in series; the second LC branch includes a second inductor L2 and a second capacitor C2, which are connected to a first connection node K1, which is located between the RF coupling capacitor C3 and the RF input terminal J1; the first LC branch includes a second inductor L2 and a second capacitor C2, which are connected in series; the second LC branch includes a The capacitor terminals of the two LC branches are grounded, and the second LC branch and the RF coupling capacitor C3 form a parallel resonant response circuit. The first LC branch, the second LC branch, and the RF coupling capacitor C3 together form a Π-type high-pass filter circuit, which can work together to suppress and protect against strong electromagnetic pulses. The fourth connection node K4, located between the first inductor L1 and the first capacitor C1, and the third connection node K3, located between the second inductor L2 and the second capacitor C2, are connected by a stub. The stub, together with the first inductor L1 and the second inductor L2, form a slow-edge strong electromagnetic pulse transmission channel. An electromagnetic pulse protection and suppression device is electrically connected between the stub and ground to form a constant impedance circuit structure. The impedance value of the constant impedance circuit structure is constant, and the impedance value of the constant impedance circuit structure does not change significantly when the electromagnetic pulse protection and suppression device fails. The electromagnetic pulse protection and suppression device is an open-circuit device that is normally in an open-circuit state. It is triggered only when the amplitude of the slow-edge strong electromagnetic pulse reaches its activation voltage to discharge pulse energy.

2. The electromagnetic pulse protection circuit as described in claim 1, characterized in that, The electromagnetic pulse protection and suppression device adopts a voltage and current switching device.

3. The electromagnetic pulse protection circuit as described in claim 2, characterized in that, The voltage and current switching device includes one of a gas discharge tube, a transient voltage suppression diode, and a PIN diode.

4. The electromagnetic pulse protection circuit as described in claim 2, characterized in that, The electromagnetic pulse protection and suppression device includes a short-circuit stub, which can directly discharge the surge overcurrent induced by the slow-edge strong electromagnetic pulse to ground.

5. The electromagnetic pulse protection circuit as described in any one of claims 1-4, characterized in that, The first inductor L1 and the second inductor L2 have the same specifications; the first capacitor C1 and the second capacitor C2 have the same specifications, and are used to offset the stray capacitance and stray inductance of the LC branch, thereby expanding the operating frequency band.

6. The electromagnetic pulse protection circuit as described in claim 1, characterized in that, Remove the first capacitor C1 or the second capacitor C2 in the electromagnetic pulse protection circuit and replace them with a short-circuited stub wire. After replacement, a symmetrical reciprocal strong transient electromagnetic pulse suppression circuit is formed.

7. A radio frequency transceiver system, characterized in that, The system includes an electromagnetic pulse protection circuit as described in any one of claims 1-6, wherein the electromagnetic pulse protection circuit is connected in series between the antenna and the radio frequency chip of the radio frequency transceiver system, and is used to protect the radio frequency chip from damage caused by the slow-edge strong electromagnetic pulse.

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