Transmit-receive integrated electromagnetic protection module suitable for ship automatic identification system

Abstract

The invention relates to a receiving and transmitting integrated electromagnetic protection module suitable for a ship automatic identification system, and the module comprises a housing and an internal circuit, and the internal circuit comprises a discharge tube, a transient suppression tube, a first-stage filter circuit, a second-stage filter circuit, and a third-stage filter circuit. Wherein the discharge tube, the transient suppression tube, the first-stage filter circuit, the second-stage filter circuit and the third-stage filter circuit are connected with one another. According to the invention, a multi-stage filtering and multi-stage combined protection circuit multiplexing mode is adopted, and the receiving and transmitting branch is protected from being damaged by strong electromagnetic energy while signal transmitting and normal working signal receiving of the ship automatic identification system are not influenced. The device is based on receiving and transmitting integrated electromagnetic protection, and can be directly loaded between a receiving and transmitting antenna and an automatic identification system host, thereby completing lightning and strong electromagnetic dual reinforcement of the ship automatic identification system, and ensuring that the ship automatic identification system can simultaneously complete signal sending and receiving work in the same frequency band.

Description

Technical Field

[0001] The invention belongs to the technical field of electromagnetic protection, and in particular to a transceiver-integrated electromagnetic protection module suitable for a ship automatic identification system. Background Art

[0002] The Automatic Identification System (AIS) is an essential equipment for ships to improve the efficiency of entering and leaving ports and protect the safety of waterways. According to relevant IMO regulations, international ships over 300 tons and domestic ships over 500 tons must be equipped with AIS. In actual situations, most ships are equipped with AIS. In addition to the host, the AIS also includes an AIS antenna that transmits and receives signals. The operating frequency band is 150MHz-160MHz, which belongs to the ultra-short wave band. This frequency band is susceptible to electromagnetic interference, including interference caused by natural and human factors such as lightning and electromagnetic pulses (EMP). Lightning pulses are transient electromagnetic pulses with extremely high electromagnetic field intensity, extremely wide frequency distribution, large impact current, and slow rising edge. The characteristics of its rapid and complex waveform make it difficult for electronic equipment to withstand its impact, which can easily lead to damage or failure. Strong electromagnetic pulses have a steep rising front and extremely high peak field strength. The frequency covers the entire band from ultra-short waves to microwaves. They are extremely lethal and pose a threat to the internal components of radio frequency circuits.

[0003] When sailing in the ocean or in special areas, the ship automatic identification system is of great significance to navigation safety and is an indispensable navigation aid. However, its antenna port may be damaged by the introduction of lightning or strong electromagnetic pulses, affecting the safety of the ship. With the rapid development of informatization, the RF protection of radio frequency electronic equipment against electromagnetic pulses has received great attention. Therefore, it is very important to design strong electromagnetic pulse protection for the ship automatic identification system to ensure the safe and stable operation of the transceiver equipment in a complex electromagnetic environment, thereby ensuring the continuity and reliability of AIS information reception and transmission.

[0004] The ship automatic identification system has a special wireless communication link, which can send and receive signals simultaneously in the same frequency band. The AIS transceiver antenna is an important part of the ship automatic identification system and is exposed to the external space of the ship's compass deck for a long time. It has no cabin or other structural protection and is extremely vulnerable to lightning and strong electromagnetic pulses. Especially in areas with frequent lightning activities or near electromagnetic pulse sources, powerful transient electromagnetic pulses will enter the RF front end through "front door coupling" such as antennas, which will have great destructive power on electronic equipment and can instantly generate extremely high voltage and current, causing damage to the equipment or even burning.

[0005] Most traditional protection methods use single-stage or multi-stage limiters. If they are added to the ship automatic identification system, they can only protect the receiving link from the threat of strong electromagnetic pulses, but they are useless for scenarios where both transmission and reception are shared. When the transmission signal reaches the startup threshold of the protection module, the transmission signal will be sharply attenuated, which will have a serious impact on the communication quality of the transmission system. That is, there is no damage to the receiving end, but the transmission link cannot be transmitted, making the ship automatic identification system for both transmission and reception unable to complete its function. In addition, due to the differences in frequency and time domain waveform characteristics between lightning pulses and strong electromagnetic pulses, conventional electromagnetic protection modules can only protect against one type of pulse. Considering today's complex and changeable electromagnetic environment, it is necessary to develop a protection module that combines lightning pulses and strong electromagnetic pulses.

[0006] In recent years, no clear radio frequency protection scheme for the ship automatic identification system has been found. There are similar schemes such as shortwave / ultra-short wave radio frequency protection module schemes, and the relevant protection schemes are mainly aimed at reports from the receiving branch; for example, CN2202211380751.1, a vehicle-mounted ultra-short wave radio strong electromagnetic pulse protection device, and CN201511010969.8 shortwave radio high-altitude nuclear electromagnetic pulse protection device. There are few protection modules in the prior art that can be shared by both the receiving and transmitting ends. Summary of the invention

[0007] The purpose of the present invention is to overcome the shortcomings of the prior art and propose a transceiver integrated electromagnetic protection module suitable for the ship automatic identification system, which adopts a multi-stage filtering and multi-stage combined protection circuit multiplexing method to protect the transceiver branch from being damaged by strong electromagnetic energy without affecting the normal operation of the ship automatic identification system to transmit and receive signals. The present invention is based on the transceiver integrated electromagnetic protection, which can be directly loaded between the transceiver antenna and the host of the automatic identification system, thereby completing the lightning and strong electromagnetic dual reinforcement of the ship automatic identification system, ensuring that it can complete the signal transmission and reception work in the same frequency band at the same time.

[0008] The present invention solves the technical problem by adopting the following technical solutions:

[0009] A transceiver integrated electromagnetic protection module suitable for a ship automatic identification system comprises a shell and an internal circuit, wherein the internal circuit is installed in the shell, and the shell comprises a first radio frequency connector and a second radio frequency connector, wherein the first radio frequency connector is connected to an antenna feed part, and the second radio frequency connector is connected to a protected end.

[0010] Moreover, the internal circuit includes a discharge tube, a transient suppression tube, a primary filter circuit, a secondary filter circuit and a tertiary filter circuit, wherein the discharge tube, the transient suppression tube, the primary filter circuit, the secondary filter circuit and the tertiary filter circuit are interconnected.

[0011] Moreover, the discharge tube is connected to the first RF connector, the three-stage filter circuit is connected to the second RF connector, the protected end receives the signal of the antenna feed part through the discharge tube, the transient suppression tube, the first-stage filter circuit, the second-stage filter circuit and the third-stage filter circuit in sequence, and the protected end sends the signal to the antenna feed part through the three-stage filter circuit, the second-stage filter circuit, the first-stage filter circuit, the transient suppression tube and the discharge tube in sequence.

[0012] Moreover, the discharge tube adopts a gas discharge tube, and the transient voltage suppressor adopts a transient voltage suppression diode TVS, which provides more comprehensive and efficient overvoltage protection by utilizing the complementary advantages of the gas discharge tube and the transient voltage suppression diode TVS.

[0013] Moreover, the first-stage filtering circuit, the second-stage filtering circuit and the third-stage filtering circuit all adopt a combination of an LC low-pass filter and a capacitor filter, and utilize the characteristics of the inductor increasing the impedance of the high-frequency signal and the capacitor reducing the impedance of the low-frequency signal to achieve the passage of the low-frequency signal and the attenuation of the high-frequency signal.

[0014] Moreover, the primary filtering circuit includes a capacitor C1, a capacitor C4 and an inductor L1, wherein the capacitor C1 and the capacitor C4 are connected in parallel, and one end of the capacitor C1 and the capacitor C4 is connected to the inductor L1.

[0015] Moreover, the secondary filtering circuit includes a capacitor C2, a capacitor C5 and an inductor L2, wherein the capacitor C2 and the capacitor C5 are connected in parallel, and one end of the capacitor C2 and the capacitor C5 is connected to the inductor L2.

[0016] Furthermore, the three-stage filtering circuit includes a capacitor C3 and a capacitor C6, wherein the capacitor C3 and the capacitor C6 are connected in parallel.

[0017] The advantages and positive effects of the present invention are:

[0018] 1. The present invention includes a shell and an internal circuit, wherein the internal circuit is installed in the shell, the shell includes a first RF connector and a second RF connector, wherein the first RF connector is connected to the antenna feed part, the second RF connector is connected to the protected end, and the internal circuit includes a discharge tube, a transient suppression tube, a primary filter circuit, a secondary filter circuit and a tertiary filter circuit, wherein the discharge tube, the transient suppression tube, the primary filter circuit, the secondary filter circuit and the tertiary filter circuit are connected to each other, the primary filter circuit, the secondary filter circuit and the tertiary filter circuit constitute a multi-stage filter, and the discharge tube and the transient suppression tube constitute a multi-stage combined protection circuit. The present invention adopts a multi-stage filtering and multi-stage combined protection circuit multiplexing method, while not affecting the normal operation of the ship automatic identification system to transmit and receive signals, and protects the transceiver branch from being damaged by strong electromagnetic energy. The present invention is based on the electromagnetic protection of transceiver integration, which can be directly loaded between the transceiver antenna and the host of the automatic identification system, thereby completing the lightning and strong electromagnetic dual reinforcement of the ship automatic identification system, ensuring that it can simultaneously complete the transmission and reception of signals in the same frequency band.

[0019] 2. The present invention can be loaded on the common transceiver branch at the rear end of the common transceiver antenna, without affecting the normal signal transmission of the ship automatic identification system, and can protect the receiving branch from strong electromagnetic energy impact. The present invention can complete the dual protection of the transceiver branch against lightning and strong electromagnetic pulses without changing the existing equipment form of the ship automatic identification system.

[0020] 3. The present invention adopts a multi-stage filtering and multi-stage combined protection circuit multiplexing method to protect the transceiver branch from being damaged by strong electromagnetic energy without affecting the normal operation of the ship automatic identification system transmitting and receiving signals. Compared with other single-stage protection circuits and single-stage filtering circuits, the present invention can withstand high-power signals of the transmitting and receiving branches, and has better small signal insertion loss (within the very high frequency band). BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the internal circuit of a transceiver integrated electromagnetic protection module suitable for a ship automatic identification system of the present invention;

[0022] Figure 2 This is an internal circuit diagram of a transceiver integrated electromagnetic protection module suitable for a ship automatic identification system of the present invention;

[0023] Figure 3 This is a schematic diagram of the structure of a transceiver integrated electromagnetic protection module suitable for a ship automatic identification system of the present invention;

[0024] Figure 4 This is an insertion loss test curve diagram of a transceiver-in-one electromagnetic protection module suitable for a ship automatic identification system according to the present invention. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below with reference to the accompanying drawings.

[0026] An electromagnetic protection module for automatic identification system of ships, such as Figure 3 As shown, it includes a shell and an internal circuit, wherein the internal circuit is installed in the shell, and the shell includes a first RF connector and a second RF connector, wherein the first RF connector is connected to the antenna feed part, and the second RF connector is connected to the protected end.

[0027] like Figure 1 As shown, the internal circuit includes a discharge tube, a transient suppression tube, a primary filter circuit, a secondary filter circuit and a tertiary filter circuit, wherein the discharge tube, the transient suppression tube, the primary filter circuit, the secondary filter circuit and the tertiary filter circuit are interconnected.

[0028] The discharge tube is connected to the first RF connector, the three-stage filter circuit is connected to the second RF connector, the protected end receives the signal of the antenna feed part through the discharge tube, the transient suppression tube, the first-stage filter circuit, the second-stage filter circuit and the third-stage filter circuit in sequence, and the protected end sends the signal to the antenna feed part through the three-stage filter circuit, the second-stage filter circuit, the first-stage filter circuit, the transient suppression tube and the discharge tube in sequence.

[0029] The discharge tube uses a gas discharge tube, and the transient voltage suppressor uses a transient voltage suppression diode TVS. By utilizing the complementary advantages of the gas discharge tube and the transient voltage suppression diode TVS, a more comprehensive and efficient overvoltage protection is provided. The first RF connector and the second RF connector are SL16 connectors, which can be adapted to the physical interfaces of mainstream domestic and foreign ship automation systems.

[0030] The first-stage filter circuit, the second-stage filter circuit and the third-stage filter circuit all use a combination of LC low-pass filters and capacitor filters, and use the characteristics of the inductor increasing the impedance of high-frequency signals and the capacitor reducing the impedance of low-frequency signals to achieve the passage of low-frequency signals and the attenuation of high-frequency signals. At the same time, the composite application of multi-stage LC low-pass filters and capacitor low-pass filters can improve the filtering performance, provide a steeper transition band and higher selectivity, and thus more effectively filter out-of-band noise, gradually reduce the ripple in the passband, and maintain the integrity of the low-frequency signal.

[0031] The primary filtering circuit includes a capacitor C1, a capacitor C4 and an inductor L1, wherein the capacitor C1 and the capacitor C4 are connected in parallel, and one end of the capacitor C1 and the capacitor C4 is connected to the inductor L1.

[0032] The secondary filtering circuit includes a capacitor C2, a capacitor C5 and an inductor L2, wherein the capacitor C2 and the capacitor C5 are connected in parallel, and one end of the capacitor C2 and the capacitor C5 is connected to the inductor L2.

[0033] The three-stage filtering circuit includes a capacitor C3 and a capacitor C6, wherein the capacitor C3 and the capacitor C6 are connected in parallel.

[0034] like Figure 2 As shown, the present invention includes a first RF connector J1, a discharge tube GDT T1, a transient voltage suppressor TVSD1, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, an inductor L1, an inductor L2 and a first RF connector J2, wherein pin 1 of the first RF connector J1 is respectively connected to pin 2 of the discharge tube GDT T1, pins 1 and 2 of the transient voltage suppressor TVSD1, one end of the capacitor C1, one end of the capacitor C2, one end of the capacitor C3, one end of the capacitor C4, one end of the capacitor C5, one end of the capacitor C6 and pin 1 of the second RF connector J2, and pin 1 of the first RF connector J1 is grounded, and pin 2 of the first RF connector J1 is respectively connected to the discharge tube GDT Pin 1 of T1, pin 3 of transient voltage suppressor TVSD1, the other end of capacitor C1, the other end of capacitor C4 and one end of inductor L1. The other end of inductor L1 is respectively connected to the other end of capacitor C2, the other end of capacitor C5 and one end of inductor L2. The other end of inductor L2 is respectively connected to the other end of capacitor C3, the other end of capacitor C6 and pin 2 of the second RF connector J2.

[0035] The working principle of the present invention is:

[0036] When the signal energy of the receiving branch and the transmitting branch (corresponding to the first RF connector and the second RF connector, respectively) is small, the normal working signal can pass through the receiving and transmitting branches with low insertion loss. When the receiving branch is attacked by a strong electromagnetic pulse, the impedance of the gas discharge tube and the transient suppression tube will change from a high impedance state to a low impedance state. The TVS tube responds first and quickly absorbs part of the transient energy, reducing the impact of the subsequent large current surge on the circuit and reducing the triggering pressure of the GDT. When the transient voltage exceeds the capacity of the TVS tube, the GDT then acts to provide an additional energy release path, which can handle a larger scale of energy release and jointly reduce the residual voltage, thereby providing more complete protection for the subsequent circuit. The multi-stage filter is an LC filter, which can gradually weaken the high-frequency components of lightning pulses and electromagnetic pulses to ensure that the internal circuits of the radio are protected from the residual pressure of electromagnetic pulses. At the same time, when the transmitting branch transmits a large signal, the protection module can withstand the impact of high power, and at this time the gas discharge tube and the transient suppression tube will not start, and will not affect the transmission of normal signals.

[0037] like Figure 4As shown, the insertion loss of the integrated transceiver electromagnetic protection module at DC-200MHz is less than 0.2dB, which will not affect the communication signal quality of the ship automatic identification system. At the same time, after testing, the present invention can achieve low insertion loss in the passband below 200MHz, and achieve a continuous wave transmission tolerance power of more than 150W; and achieve broadband suppression in the out-of-band frequency band above 200MHz to cope with the damage of lightning pulses and high-power microwaves to the subsequent circuits.

[0038] The present invention adopts a multi-stage filtering and multi-stage combined protection circuit multiplexing method to protect the transceiver branch from being damaged by strong electromagnetic energy without affecting the normal signal transmission and reception of the ship automatic identification system. The present invention is based on the electromagnetic protection of transceiver integration, which can be directly loaded between the transceiver antenna and the host of the automatic identification system, thereby completing the lightning and strong electromagnetic dual reinforcement of the ship automatic identification system, ensuring that it can complete the signal transmission and reception work in the same frequency band at the same time.

[0039] The present invention can be loaded on the common transceiver branch at the rear end of the common transceiver antenna, without affecting the normal signal transmission of the ship automatic identification system, and can protect the receiving branch from strong electromagnetic energy impact. The present invention can complete the dual protection of the transceiver branch against lightning and strong electromagnetic pulses without changing the existing equipment form of the ship automatic identification system.

[0040] The present invention adopts a multi-stage filtering and multi-stage combined protection circuit multiplexing method to protect the transceiver branch from being damaged by strong electromagnetic energy without affecting the normal operation of the ship automatic identification system transmitting and receiving signals. Compared with other single-stage protection circuits and single-stage filtering circuits, the present invention can withstand high-power signals of the transmitting and receiving branches, and has better small signal insertion loss (within the very high frequency band).

[0041] It should be emphasized that the embodiments described in the present invention are illustrative rather than restrictive. Therefore, the present invention includes but is not limited to the embodiments described in the specific implementation manner. Any other implementation manners derived by those skilled in the art based on the technical solution of the present invention also fall within the scope of protection of the present invention.

Claims

1. A transceiver integrated electromagnetic protection module suitable for a ship automatic identification system, characterized in that: It comprises a shell and an internal circuit, wherein the internal circuit is installed in the shell, and the shell comprises a first RF connector and a second RF connector, wherein the first RF connector is connected to the antenna feed part, and the second RF connector is connected to the protected end.

2. According to claim 1, a transceiver integrated electromagnetic protection module suitable for a ship automatic identification system, characterized in that: The internal circuit includes a discharge tube, a transient suppression tube, a primary filter circuit, a secondary filter circuit and a tertiary filter circuit, wherein the discharge tube, the transient suppression tube, the primary filter circuit, the secondary filter circuit and the tertiary filter circuit are connected to each other.

3. The transceiver integrated electromagnetic protection module suitable for a ship automatic identification system according to claim 2, characterized in that: The discharge tube is connected to the first RF connector, the three-stage filter circuit is connected to the second RF connector, the protected end receives the signal of the antenna feed part through the discharge tube, the transient suppression tube, the first-stage filter circuit, the second-stage filter circuit and the third-stage filter circuit in sequence, and the protected end sends the signal to the antenna feed part through the three-stage filter circuit, the second-stage filter circuit, the first-stage filter circuit, the transient suppression tube and the discharge tube in sequence.

4. The transceiver integrated electromagnetic protection module suitable for a ship automatic identification system according to claim 2, characterized in that: The discharge tube adopts a gas discharge tube, and the transient voltage suppressor adopts a transient voltage suppression diode TVS, which provides more comprehensive and efficient overvoltage protection by utilizing the complementary advantages of the gas discharge tube and the transient voltage suppression diode TVS.

5. The transceiver integrated electromagnetic protection module suitable for ship automatic identification system according to claim 2, characterized in that: The first-stage filtering circuit, the second-stage filtering circuit and the third-stage filtering circuit all adopt a combination of an LC low-pass filter and a capacitor filter, and utilize the characteristics of the inductor increasing the impedance of the high-frequency signal and the capacitor reducing the impedance of the low-frequency signal to achieve the passage of the low-frequency signal and the attenuation of the high-frequency signal.

6. The transceiver integrated electromagnetic protection module suitable for ship automatic identification system according to claim 5, characterized in that: The primary filter circuit includes a capacitor C1, a capacitor C4 and an inductor L1, wherein the capacitor C1 and the capacitor C4 are connected in parallel, and one end of the capacitor C1 and the capacitor C4 is connected to the inductor L1.

7. The transceiver integrated electromagnetic protection module suitable for a ship automatic identification system according to claim 5, characterized in that: The secondary filtering circuit includes a capacitor C2, a capacitor C5 and an inductor L2, wherein the capacitor C2 and the capacitor C5 are connected in parallel, and one end of the capacitor C2 and the capacitor C5 is connected to the inductor L2.

8. The transceiver integrated electromagnetic protection module suitable for a ship automatic identification system according to claim 5, characterized in that: The three-stage filtering circuit includes a capacitor C3 and a capacitor C6, wherein the capacitor C3 and the capacitor C6 are connected in parallel.

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