Novel network port three-level filter

Abstract

The utility model discloses a novel network port three-level filter, which is characterized in that a first network port unit connected with a first network port female seat, a filtering protection unit and a second network port unit connected with a second network port female seat are arranged on a circuit board; the filtering protection unit comprises a surge protection module, a first common-mode filtering module, a first high-frequency filtering module, a second common-mode filtering module, a second high-frequency filtering module and a third common-mode filtering module which are connected in sequence, and the filtering protection unit forms three-stage filtering, so that attenuation of useful signals in a line can be reduced; the balance effect of the filter in the whole frequency band is improved, the surge protection module can effectively suppress surge signals in a network, and the first high-frequency filtering module and the second high-frequency filtering module can reduce the penetrability of high-frequency signals on the line, so that the working performance of the product is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of filters, and in particular relates to a novel network port three-stage filter. Background Art

[0002] The mixed network port circuit is generally composed of a network port transformer, a termination resistor and a high-voltage capacitor, which interconnects the network interface with the network interface chip. Its circuit structure is relatively complex. The traditional network port circuit can suppress the electromagnetic interference of the network port and ensure the effective transmission of network port data. In high-frequency communication lines, there is usually excessive signal attenuation, which is easy to be connected to external high-frequency interference signals. The use of network port filters can effectively suppress interference on high-frequency signal lines, but the network port filter is an inductive component filter. When the attenuation reaches 10dB at 100MHz, it is easy to have large signal attenuation, resulting in unstable signal transmission. At the same time, surge signals will appear in the network and damage the line, which seriously affects the normal operation of other equipment. Utility Model Content

[0003] In view of the above problems, the utility model provides a novel network port three-stage filter, which can improve the shielding effectiveness and adjust the filtering effect, so that the product has better suppression ability at high frequencies, so as to solve the problems raised in the above background technology.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] The utility model provides a novel network port three-stage filter, the novel network port three-stage filter comprises a housing, a circuit board arranged in the housing, a first network port female socket located at one end of the circuit board and a second network port female socket located at the other end of the circuit board, the circuit board comprises a first network port unit connected to the first network port female socket, a filtering protection unit, and a second network port unit connected to the second network port female socket, the first network port unit, the filtering protection unit and the second network port unit are connected in sequence;

[0006] The filtering protection unit includes a surge protection module, a first common mode filtering module, a first high frequency filtering module, a second common mode filtering module, a second high frequency filtering module and a third common mode filtering module connected in sequence;

[0007] The surge protection module includes a plurality of ceramic gas discharge tubes, which are used to suppress the surge impact of short-circuit current in the circuit where the network port is located;

[0008] The first common-mode filter module, the second common-mode filter module and the third common-mode filter module each include a plurality of common-mode chip inductors, which are used to suppress the common-mode noise of the network port;

[0009] The first high-frequency filtering module and the second high-frequency filtering module each include a plurality of chip capacitors, which are used to suppress high-frequency components and noise of the network port.

[0010] As a further preferred embodiment of the above technical solution, the novel network port three-stage filter further includes a cover body and a plurality of limiting protrusions arranged on the shell, and the cover body is sealed and installed through the plurality of limiting protrusions.

[0011] As a further preferred embodiment of the above technical solution, the first network port socket is installed on the shell through a plurality of nuts, and the connection port of the first network port socket is located at the bottom of the shell.

[0012] As a further preferred embodiment of the above technical solution, the first network port socket and the second network port socket are respectively plugged into the circuit board, and a connection port of the second network port socket is located on a side surface of the shell.

[0013] As a further preferred embodiment of the above technical solution, the inductance value of each chip inductor in the first common-mode filtering module, the second common-mode filtering module and the third common-mode filtering module is 20nH.

[0014] As a further preferred embodiment of the above technical solution, the capacitance of each chip capacitor in the first high-frequency filtering module and the second high-frequency filtering module is 33 pF.

[0015] As a further preferred embodiment of the above technical solution, the number of the surge protection module, the first common mode filtering module, the first high frequency filtering module, the second common mode filtering module, the second high frequency filtering module and the third common mode filtering module are all four.

[0016] As a further preferred embodiment of the above technical solution, the shell is made of metal.

[0017] As a further preferred embodiment of the above technical solution, both the first network port unit and the second network port unit are RJ45 interfaces.

[0018] Compared with the prior art, the beneficial effects of the utility model are:

[0019] By arranging a first network port unit connected to the first network port socket, a filtering protection unit, and a second network port unit connected to the second network port socket on the circuit board, the filtering protection unit includes a surge protection module, a first common mode filtering module, a first high-frequency filtering module, a second common mode filtering module, a second high-frequency filtering module and a third common mode filtering module which are connected in sequence, and the filtering protection unit forms a three-stage filtering, which can reduce the attenuation of useful signals in the line and improve the balancing effect of the filter in the entire frequency band. The surge protection module can effectively suppress surge signals in the network, and the first high-frequency filtering module and the second high-frequency filtering module can reduce the penetration of high-frequency signals on the line, thereby improving the working performance of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a structural diagram of the new type of network port three-stage filter proposed by the utility model;

[0021] Figure 2 This is the circuit diagram of the novel network port three-stage filter proposed by the utility model;

[0022] Figure 3 This is the inductor winding principle diagram proposed by the utility model;

[0023] Figure 4 This is an attenuation effect diagram of the new network port three-stage filter proposed in the utility model.

[0024] The main component symbols are described as follows:

[0025] 100-housing; 110-circuit board; 120-first network port socket; 130-second network port socket; 140-first network port unit; 150-filter protection unit; 160-second network port unit; 170-surge protection module; 180-first common mode filter module; 190-first high-frequency filter module; 200-second common mode filter module; 210-second high-frequency filter module; 220-third common mode filter module; 230-cover; 240-limiting bump; 250-nut. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0027] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0028] See also Figure 1 and Figure 2 The utility model provides a novel network port three-stage filter, the novel network port three-stage filter comprises a housing 100, a circuit board 110 arranged in the housing 100, a first network port female socket 120 located at one end of the circuit board 110 and a second network port female socket 130 located at the other end of the circuit board 110, the circuit board 110 comprises a first network port unit 140 connected to the first network port female socket 120, a filtering protection unit 150, and a second network port unit 160 connected to the second network port female socket 130, the first network port unit 140, the filtering protection unit 150 and the second network port unit 160 are connected in sequence;

[0029] The filtering protection unit 150 includes a surge protection module 170, a first common mode filtering module 180, a first high frequency filtering module 190, a second common mode filtering module 200, a second high frequency filtering module 210 and a third common mode filtering module 220 connected in sequence;

[0030] The surge protection module 170 includes a plurality of ceramic gas discharge tubes, which are used to suppress the surge impact of short-circuit current in the circuit where the network port is located;

[0031] The first common-mode filter module 180, the second common-mode filter module 200 and the third common-mode filter module 220 each include a plurality of common-mode chip inductors, which are used to suppress the common-mode noise of the network port;

[0032] The first high-frequency filtering module 190 and the second high-frequency filtering module 210 both include a plurality of chip capacitors, which are used to suppress high-frequency components and noise of the network port.

[0033] In this embodiment, the novel network port three-stage filter further includes a cover 230 and a plurality of limiting protrusions 240 arranged on the housing 100, and the cover 230 is sealed and installed by the plurality of limiting protrusions 240. The first network port female socket 120 is installed on the housing 100 by a plurality of nuts 250, and the connection port of the first network port female socket 120 is located at the bottom of the housing 100. The first network port female socket 120 and the second network port female socket 130 are respectively plugged with the circuit board 110, and the connection port of the second network port female socket 130 is located on the side of the housing 100. The inductance value of each chip inductor in the first common mode filter module 180, the second common mode filter module 200 and the third common mode filter module 220 is 20nH. The capacity of each chip capacitor in the first high-frequency filter module 190 and the second high-frequency filter module 210 is 33pF, the number of the surge protection module 170, the first common-mode filter module 180, the first high-frequency filter module 190, the second common-mode filter module 200, the second high-frequency filter module 210 and the third common-mode filter module 220 are all four, the shell 100 is made of metal, the first network port unit 140 is marked as WK1 and the second network port unit 160 is marked as WK2, both of which are RJ45 interfaces. The number of nuts 250 is four, the number of limit bumps 240 is eight, and two are arranged on each end face of the upper surface of the shell 100. The filter of the utility model is simpler and more convenient to install and use. For modular installation, the communication inside and outside the shielding cabin is guaranteed to be stable by suppressing high-frequency interference, and also prevents the equipment from being damaged by strong external pulse shocks.

[0034] It should be noted that the ceramic gas discharge tube (GDT) is the most widely used switching device in lightning protection equipment. Whether it is lightning protection for AC and DC power supplies or lightning protection for various signal circuits, it can be used to discharge lightning current into the ground. The first high-frequency filter module 190 and the second high-frequency filter module 210 are capacitors X7 type flat capacitors 22pF, or capacitors with a capacity of about 22pF. The surge protection module 170 can also be GTVS, and surge protection devices with different parameters are selected to achieve different surge protection capabilities. The winding inductor is simulated according to the loop design of the product, and different numbers of turns, different diameters, and different wire diameters are used to obtain similar inductances. Adjacent chip capacitors and inductors form LC filtering. The filter protection unit 150 mainly includes four branches, each of which includes a surge protection module 170 denoted as GDT, three chip common mode inductors denoted as L and two chip capacitors C. Taking the first branch as an example, GDT1, L1, C1, C2, L5, C9, C10 and L9, each branch contains three-stage filtering, which can achieve the balance effect of the filter in the entire frequency band. The common mode inductor is a hollow inductor that can reduce the attenuation of useful signals in the line. The use of metal for the outer shell can improve the shielding performance of the filter, and multiple electronic components can be accommodated between the circuit board and the shell, thereby improving the high-frequency performance of the magnetic components.

[0035] Specifically, see Figure 3 and Figure 4 , design a low-pass filter, attenuate 3dB at 100MHz, 20dB attenuation at 200MHz, 60dB at 300MHz, matching impedance is 75Ω, filter range is 100MHz-18GHz. Solve the problems existing in the background technology by using wire-wound inductors. Wire-wound inductors have the following advantages: large current carrying ratio and good surge protection, and will not cause secondary damage to the sensitive devices behind due to the large distributed capacitance of the inductor itself. Wire-wound inductors are calculated by the formula L=4*10 -7 *l*(ln(2a / d)-a / l), where l is the line length, a is the coil diameter, and d is the line length. After building the components, make overall adjustments to reduce the distributed capacitance and ensure the high-frequency flatness and attenuation performance of the filter. The test results after adjustment are as follows: Figure 4 As shown, INSERTION LOSS represents insertion loss. It is easy to understand that the interference existing on any two power lines can be expressed by common mode interference and differential mode interference. Common mode interference is transmitted between the wire and the ground (casing), which is an asymmetric interference, which is defined as an undesirable potential difference between any current-carrying conductor and the reference ground; differential mode interference is transmitted between two wires, which is a symmetrical interference, which is defined as an undesirable potential difference between any two current-carrying conductors; common mode interference has a large amplitude and high frequency, and can also radiate through the wire, causing greater interference. Differential mode interference has a small amplitude and low frequency, causing less interference.

[0036] In addition, the packaging process of the filter of the utility model is: first, the inductor module is potted for the first time, and then the entire shell is potted for the second time. Potting inspection, the potting glue meets the requirements of insulation properties, dielectric constant, and Uo. Finally, the metal shell is completely soldered to reduce electromagnetic leakage. The test conclusion is: the attenuation performance is good, and the performance is improved or reduced by adjusting the number of levels, and the performance is stable. The shielding performance is good, reaching more than 120DB. The surge resistance can reach the surge impact of 4KA short-circuit current.

[0037] It should be understood that by arranging a first network port unit 140 connected to the first network port socket 120, a filtering protection unit 150, and a second network port unit 160 connected to the second network port socket 130 on the circuit board 110, the filtering protection unit 150 includes a surge protection module 170, a first common mode filtering module 180, a first high-frequency filtering module 190, a second common mode filtering module 200, a second high-frequency filtering module 210 and a third common mode filtering module 220 connected in sequence, and the filtering protection unit 150 forms a three-stage filtering, which can reduce the attenuation of useful signals in the line, and also improve the balancing effect of the filter in the entire frequency band. The surge protection module 170 can effectively suppress surge signals in the network, and the first high-frequency filtering module 190 and the second high-frequency filtering module 210 can reduce the penetration of high-frequency signals on the line, thereby improving the working performance of the product.

[0038] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A new type of network port three-stage filter, It is characterized in that The novel network port three-stage filter comprises a housing, a circuit board arranged in the housing, a first network port female socket located at one end of the circuit board, and a second network port female socket located at the other end of the circuit board, the circuit board comprises a first network port unit connected to the first network port female socket, a filtering protection unit, and a second network port unit connected to the second network port female socket, the first network port unit, the filtering protection unit and the second network port unit are connected in sequence; The filtering protection unit includes a surge protection module, a first common mode filtering module, a first high frequency filtering module, a second common mode filtering module, a second high frequency filtering module and a third common mode filtering module connected in sequence; The surge protection module includes a plurality of ceramic gas discharge tubes, which are used to suppress the surge impact of short-circuit current in the circuit where the network port is located; The first common-mode filter module, the second common-mode filter module and the third common-mode filter module each include a plurality of common-mode chip inductors, which are used to suppress the common-mode noise of the network port; The first high-frequency filtering module and the second high-frequency filtering module each include a plurality of chip capacitors, which are used to suppress high-frequency components and noise of the network port.

2. The novel network port three-stage filter according to claim 1, It is characterized in that The novel network port three-stage filter also includes a cover body and a plurality of limiting protrusions arranged on the shell, and the cover body is sealed and installed through the plurality of limiting protrusions.

3. The novel network port three-stage filter according to claim 1, It is characterized in that The first network port socket is installed on the shell through a plurality of nuts, and the connection port of the first network port socket is located at the bottom of the shell.

4. The novel network port three-stage filter according to claim 3, It is characterized in that The first network port socket and the second network port socket are respectively plugged into the circuit board, and a connection port of the second network port socket is located on a side surface of the shell.

5. The novel network port three-stage filter according to claim 1, It is characterized in that The inductance value of each chip inductor in the first common-mode filtering module, the second common-mode filtering module and the third common-mode filtering module is 20nH.

6. The novel network port three-stage filter according to claim 1, It is characterized in that The capacitance of each chip capacitor in the first high-frequency filtering module and the second high-frequency filtering module is 33 pF.

7. The novel network port three-stage filter according to claim 1, It is characterized in that The number of the surge protection module, the first common mode filtering module, the first high frequency filtering module, the second common mode filtering module, the second high frequency filtering module and the third common mode filtering module are all four.

8. The novel network port three-stage filter according to claim 1, It is characterized in that The shell is made of metal.

9. The novel network port three-stage filter according to claim 1, It is characterized in that The first network port unit and the second network port unit are both RJ45 interfaces.

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