TWI539768B - Transmission circuit for ethernet - Google Patents

Description

Transmission circuit for Ethernet

The present invention relates to a transmission circuit for an Ethernet network. More specifically, the transmission circuit of the present invention can replace the transformer of a conventional Ethernet device to provide necessary signal coupling, DC isolation, impedance matching, and filtering of common mode noise in Ethernet transmission. In addition, part of the component group design of the transmission circuit of the present invention provides additional surge protection.

With the rapid development of Internet technology, Ethernet related products have been filled with people's daily lives. The transformers in the Ethernet devices currently on the market need to be produced manually, so the cost of production is quite high. In addition, the Ethernet devices on the market do not have a surge protection function to prevent voltage surges caused by lightning strikes, static electricity or power switching actions in the environment.

In view of this, how to provide a transmission circuit that can be automatically produced and used in an Ethernet network to replace a conventional transformer and provide a surge protection function is an urgent problem to be solved in the industry.

It is an object of the present invention to provide a transmission circuit that can be automated and used in an Ethernet network to replace a conventional transformer.

In order to achieve the above object, the present invention discloses a transmission power for an Ethernet network. road. The transmission circuit has four transmission element groups. Each of the transmission element groups is coupled to an Ethernet connector and an Ethernet chip. Each of the transmission component groups includes a first capacitor, a second capacitor, a first inductor, a second inductor, a first transmission line, a second transmission line, a third transmission line, a fourth transmission line, and a first transmission line. A component group and a second component group. The first capacitor of each of the transmission element groups is connected in series with the first inductor and coupled between the first transmission line and the second transmission line. The first capacitor is coupled to the Ethernet connector through the first transmission line, and the first inductor is coupled to the Ethernet chip through the second transmission line. The second capacitor of each of the transmission element groups is connected in series with the second inductor and coupled between the third transmission line and the fourth transmission line. The second capacitor is coupled to the Ethernet connector through the third transmission line, and the second inductor is coupled to the Ethernet chip through the fourth transmission line. The first component group of each of the transmission component groups is coupled between the first transmission line and the third transmission line. The second component group of each of the transmission component groups is coupled to a first contact between the first capacitor and the first inductor and a second contact between the second capacitor and the second inductor between.

Other objects of the present invention, as well as the technical means and implementations of the present invention, will be apparent to those skilled in the art in view of the appended claims.

1‧‧‧ Ethernet application circuit

11‧‧‧Ethernet connector

13‧‧‧Transmission circuit

13a‧‧‧Transmission component group

15‧‧‧Ethernet chip

Q1‧‧‧ first contact

Q2‧‧‧second contact

C1‧‧‧First Capacitor

C2‧‧‧second capacitor

C3‧‧‧ third capacitor

C4‧‧‧fourth capacitor

R1‧‧‧ first resistor

R2‧‧‧second resistor

G1‧‧‧first ground

G2‧‧‧second ground

L1‧‧‧First Inductor

L2‧‧‧second inductor

L3‧‧‧ third inductor

L4‧‧‧fourth inductor

CS1‧‧‧First component group

CS2‧‧‧Second component group

D1‧‧‧ fast response diode

D2‧‧‧ fast response diode

TVS‧‧‧One-way transient suppression diode

BTVS‧‧‧ Bidirectional Transient Suppression Diode

BTVS1‧‧‧ first two-way transient suppression diode

BTVS2‧‧‧Second two-way transient suppression diode

GDT‧‧‧ gas discharge tube

VDR‧‧ varistor

TSPD‧‧‧Semiconductor discharge tube

T1‧‧‧ first transmission line

T2‧‧‧second transmission line

T3‧‧‧ third transmission line

T4‧‧‧ fourth transmission line

P1‧‧‧Contact

P2‧‧‧ joints

1 is a schematic diagram of an Ethernet application circuit 1 of a first embodiment of the present invention; 2A-2E is a schematic diagram of a first component group CS1 of a second embodiment of the present invention; and 3A-3E is a schematic diagram of the present invention. A schematic diagram of the second component group CS2 of the third embodiment; and 4A-4F is a schematic diagram of the first component group CS1 and/or the second component group CS2 of the fourth embodiment of the present invention.

The following examples are intended to illustrate the technical contents of the present invention and are not intended to limit the scope of the present invention. It is to be noted that in the following embodiments and drawings, elements that are not related to the present invention have been omitted and are not shown, and the dimensional relationships between the elements in the drawings are merely for ease of understanding and are not intended to limit the actual ratio.

A first embodiment of the present invention is shown in Fig. 1, which is a schematic diagram of an Ethernet application circuit 1 of the present invention. The Ethernet application circuit 1 includes an Ethernet connector 11, a transmission circuit 13, and an Ethernet chip 15.

The Ethernet connector 11 can be an Ethernet connector with an RJ-45 interface, including a Tx0+ pin, a Tx0-pin, a Tx1+ pin, a Tx1-pin, a Tx2+ pin, and a Tx2-connect. Foot, Tx3+ pin and Tx3-pin. The Ethernet chip 15 can be a chip of various manufacturers, for example, RTL8201 chip of Realtek Semiconductor Co., Ltd., which includes MD0+ pin, MD0-pin, MD1+ pin, MD1-pin, MD2+ pin, MD2. - Pin, MD3+ pin and MD3-pin. Since the main technical content of the present invention focuses on the transmission circuit 13, and those skilled in the art can easily understand the following description, it is easy to understand how the transmission circuit 13 of the present invention replaces the transformer in the conventional Ethernet application circuit. It is coupled between the Ethernet connector 11 and the Ethernet chip 15, so the Ethernet connector 11 and the Ethernet chip 15 are not described here. In other embodiments, the transmission circuit 13 may be built into the Ethernet connector 11, however, possible implementations of the present invention are not limited to the forms disclosed herein, but may have various variations and Modification.

The transmission circuit 13 includes four transmission element groups 13a. Each of the transmission element groups 13a is coupled between the Ethernet connector 11 and the Ethernet chip 15. Each transmission element group 13a includes a first a capacitor C1, a second capacitor C2, a first inductor L1, a second inductor L2, a first transmission line T1, a second transmission line T2, a third transmission line T3, a fourth transmission line T4, and a first The component group CS1 and a second component group CS2.

The first capacitor C1 of each of the transmission element groups 13a is connected in series with the first inductor L1 and coupled between the first transmission line T1 and the second transmission line T2. The first capacitor C1 is coupled to the Ethernet connector 11 through the first transmission line T1, and the first inductor L1 is coupled to the Ethernet chip 15 through the second transmission line T2. The second capacitor C2 of each of the transmission element groups 13a is connected in series with the second inductor L2 and coupled between the third transmission line T3 and the fourth transmission line T4. The second capacitor C2 is connected to the Ethernet connector 11 through the third transmission line T3, and the second inductor L2 is connected to the Ethernet wafer 15 through the fourth transmission line T4. The first capacitor C1 and the second capacitor C2 can provide signal coupling and DC isolation, and the first inductor L1 and the second inductor L2 can provide impedance matching at a specific frequency and filter out common mode noise.

The first component group CA1 of each of the transmission component groups 13a is coupled between the first transmission line T1 and the third transmission line T3. The second component group CS2 of each of the transmission element groups 13a is coupled to one of the first contact Q1 between the first capacitor C1 and the first inductor L1 and the second contact between the second capacitor C2 and the second inductor L2. Between Q2. In addition, the first component group CS1 of each of the transmission component groups 13a is further coupled to a first ground terminal G1, and the second component group CS2 is more selectively coupled to a second ground terminal G2. It should be noted that the first ground terminal G1 refers to the ground end of the device casing, that is, the external ground terminal; however, the second ground terminal G2 refers to the common ground terminal, that is, the internal ground terminal, and the voltage is usually 0 volt (V). .

The transmission circuit 13 can be coupled to the first capacitor C1 and the second capacitor C2 by a circuit connection method according to FIG. 1 on a printed circuit board (PCB). The inductor L1, the second inductor L2, the first component group CS1, and the second component group CS2, and draw 24 pins from the PCB (when the second component group CS2 is to be coupled to the second ground terminal G2) or 20 The support pin (when the second component group CS2 is not required to be coupled to the second ground terminal G2) is implemented. In addition, when the ground terminal is internally connected in common, the total number of pins is 18 pins (when the second component group CS2 is to be coupled to the second ground G2) or 17 pins (when the second component The group CS2 does not need to be coupled to the second ground terminal G2).

In this way, the transmission circuit 13 of the present invention can replace the transformer in the traditional Ethernet application circuit, and is coupled between the Ethernet connector 11 and the Ethernet chip 15 to provide Ethernet transmission. Necessary signal coupling, DC isolation, impedance matching, and filtering common mode noise. The transmission circuit 13 can also be realized by a process of integrating a capacitor and an inductor into a single component, for example, using a co-fired ceramic technology. Furthermore, the transmission circuit 13 can also be implemented by using a semiconductor process and manufacturing the capacitor and the inductor on the same substrate.

Referring to Figures 2A through 2E, a second embodiment of the present invention depicts a first component group CS1 suitable for use in the first embodiment. As shown in FIGS. 2A to 2E, the first element group CS1 has three contacts P1, P2, P3 and is composed of a third inductor L3, a fourth inductor L4, and an optional protection element. The contact P1 is coupled to the first transmission line T1, the contact P2 is coupled to the third transmission line T3, and the contact P3 is coupled to the first ground end G1.

Specifically, the first element group CS1 in FIG. 2A is composed of a third inductor L3 and a fourth inductor L4. The third inductor L3 is coupled between the first transmission line T1 and the first ground terminal G1, and the fourth inductor L4 is coupled between the third transmission line T3 and the first ground terminal G1. In this aspect, the first inductor L1 and the second inductor L2 can be a common mode chock, and the inductance values of the first inductor L1 and the second inductor L2 are less than 10 microhenries (uH). ). The third inductor L3 and the fourth inductor L4 may be a coupled inductor, and the inductance values of the third inductor and the fourth inductor are greater than 15 microhenries (uH).

In addition, in the aspect of FIG. 2B to FIG. 2E, the third inductor L3 is connected in series with the fourth inductor L4 and coupled between the first transmission line T1 and the third transmission line T3. Protective element (for example, semiconductor discharge tube TSPD of FIG. 2B, varistor VDR of FIG. 2C, gas discharge tube GDT of FIG. 2D, or unidirectional transient suppression diode of FIG. 3E, but is not limited thereto) It is coupled between a junction between the third inductor L3 and the fourth inductor L4 and the first ground terminal G1.

In the transmission circuit 13, the first component group CS1 has surge protection capability and is capacitive to provide a path for filtering noise. When the first component group CS1 is in the aspect of FIG. 3A, the transmission circuit 13 is applicable to a non-Ethernet power supply/receiving device in a simple Ethernet application, and when the first component group CS1 is the 2B In the aspect of FIG. 2E, the transmission circuit 13 can be used for an Ethernet powered/receivable device in addition to a non-Ethernet powered/received device.

Referring to Figures 3A through 3E, a third embodiment of the present invention depicts a second component group CS2 suitable for use in the first embodiment. In the transmission circuit 13, the second element group CS2 provides a matching effect on the circuit by utilizing the capacitance characteristics of the element, and provides a function of surge protection by utilizing the collapse characteristic of the diode element. As shown in FIGS. 3A to 3E, the second element group CS2 has a pattern of two contacts P1, P2 and three contacts P1, P2, P3. The contact P1 is coupled to the first contact Q1 between the first capacitor C1 and the first inductor L1, and the contact P2 is coupled to the second contact Q2 between the second capacitor C2 and the second inductor L2. And the contact P3 is coupled to the second ground end G2.

In FIG. 3A, the second component group CS2 includes a bidirectional transient suppression diode BTVS coupled between the first contact Q1 and the second contact Q2. In Figure 3B, the second component group CS2 includes a first bidirectional transient suppression diode BTVS1 and a second bidirectional transient suppression diode BTVS2. The first bidirectional transient suppression diode BTVS1 is coupled between the first contact Q1 and the second ground terminal G2, and the second bidirectional transient suppression diode BTVS2 is coupled to the second contact Q2 and the second ground. Between the ends G2.

In FIG. 3C, the second component group CS2 includes a first bidirectional transient suppression diode BTVS1, a second bidirectional transient suppression diode BTVS2, and a third inductor L3. The first bidirectional transient suppression diode BTVS1 is connected in series with the second bidirectional transient suppression diode BTVS2 and coupled between the first contact Q1 and the second contact Q2. The third inductor L3 is coupled between the first contact between the first bidirectional transient suppression diode BTVS1 and the second bidirectional transient suppression diode BTVS2 and the second ground terminal G2.

In FIG. 3D, the second component group CS2 includes a first fast reacting diode set, a second fast reacting diode set, and a unidirectional transient suppression diode TVS. The first fast-reacting diode group includes two fast-reacting diodes D1 connected in series, and one of the contacts is coupled to the first contact Q1. The second fast-reacting diode group includes two fast-reacting diodes D2 in series, and one of the contacts is coupled to the second contact Q2. The unidirectional transient suppression diode TVS is connected in parallel with the first fast-reaction diode group and the second fast-reaction diode group, and is coupled to the second ground terminal G2.

In FIG. 3E, the second component group CS2 includes a third inductor L3, a first fast reacting diode set, a second fast reacting diode set, and a unidirectional transient suppression diode TVS. The first fast-reacting diode group includes two fast-reacting diodes D1 connected in series, and the contact therebetween is coupled to the first contact Q1. The second fast-reacting diode group includes two fast-reacting diodes D2 in series and the junction therebetween is coupled to the second junction Q2. One-way transient suppression diode TVS, with the first The fast reacting diode group and the second fast reacting diode group are connected in parallel in parallel, and are coupled to the second grounding terminal G2 through the third inductor L3.

In addition, in the aspects of the 3C and 3E modes, the third inductor L3 is added between the second ground terminals G2 to additionally provide a common mode filtering effect to process common mode noise at a specific frequency. It should be noted that, in addition to the aspects illustrated in FIGS. 3A to 3E, any component that can provide appropriate capacitance between the first contact Q1 and the second contact Q2 can achieve a matching effect, and any has a collapse, The components of the clamp and/or switching characteristics can provide a surge protection function, so the protection range of the second component group CS2 of the present invention is not limited to the aspects of FIGS. 3A to 3E.

Referring to the fourth embodiment of the present invention, reference is made to Figures 4A through 4F, which depict a first component group CS1 and/or a second component group CS2 suitable for use in the first embodiment.

4B, 4D, 4E, and 4F are applicable to the first component group CS1, the contact P1 is coupled to the first transmission line T1, and the contact P2 is coupled to the third transmission line T3. And the contact P3 is coupled to the first ground terminal G1. In FIG. 4B, the first component group CS1 includes a first resistor R1 and a second resistor R2. The first resistor R1 is coupled between the first transmission line T1 and the first ground terminal G1, and the second resistor R2 is coupled between the third transmission line T3 and the first ground terminal G1. In FIG. 4D, the first component group CS1 includes a third capacitor C3 and a fourth capacitor C4. The third capacitor C3 is coupled between the first transmission line T1 and the first ground terminal G1, and the fourth capacitor C4 is coupled between the third transmission line T3 and the first ground terminal G1.

In FIG. 4E, the first element group CS1 includes a third capacitor C3, a fourth capacitor C4, and a third inductor L3. The third capacitor C3 is connected in series with the fourth capacitor C4 and coupled between the first transmission line T1 and the third transmission line T3. The third inductor L3 is coupled between one of the contacts between the third capacitor C3 and the fourth capacitor C4 and the first ground terminal G1. In Figure 4F, the first component group CS1 The third capacitor C3, the fourth capacitor C4, the third inductor L3, and the fourth inductor L4 are connected in series. The third capacitor C3 is coupled to the first transmission line T1, and the fourth capacitor C4 is coupled to the third transmission line T3. A contact between the third inductor L3 and the fourth inductor L4 is coupled to the first ground terminal G1.

On the other hand, the aspects of the 4A to 4F are applicable to the second component group CS2, the contact P1 is coupled to the first contact Q1, the contact P2 is coupled to the second contact Q2, and the connection is The point P3 is coupled to the second ground terminal G2. In FIG. 4A, the second component group CS2 includes a first resistor R1 coupled between the first contact Q1 and the second contact Q2. In FIG. 4B, the second component group CS2 includes a first resistor R1 and a second resistor R2. The first resistor R1 is coupled between the first contact Q1 and the second ground G2, and the second resistor R2 is coupled between the second contact Q2 and the second ground G2.

In FIG. 4C, the second component group CS2 includes a third capacitor C3 coupled between the first contact Q1 and the second contact Q2. In FIG. 4D, the second element group CS2 includes a third capacitor C3 and a fourth capacitor C4. The third capacitor C3 is coupled between the first contact Q1 and the second contact Q2, and the fourth capacitor C4 is coupled between the second contact Q2 and the second ground G2.

In FIG. 4E, the second element group CS2 includes a third capacitor C3, a fourth capacitor C4, and a third inductor L3. The third capacitor C3 is connected in series with the fourth capacitor C4 and coupled between the first contact Q1 and the second contact Q2. The third inductor L3 is coupled between one of the contacts between the third capacitor C3 and the fourth capacitor C4 and the second ground terminal G2. In FIG. 4F, the second element group CS2 includes a third capacitor C3, a fourth capacitor C4, a third inductor L3, and a fourth inductor L4 connected in series. The third capacitor C3 is coupled to the first contact Q1, and the fourth capacitor C4 is coupled to the second contact Q2. A contact between the third inductor L3 and the fourth inductor L4 is coupled to the second ground terminal G2.

When the first component group CS1 is in the 4B, 4D, 4E, and 4F modes, it does not have the surge protection capability, but is mainly used to provide a path for filtering the common mode noise. Similarly, when the second component group CS2 is in the form of the 4A to 4F diagrams, there is no surge protection capability. In addition, when the first component group CS1 and the second component group CS2 are simultaneously applicable, the transmission circuit 13 does not have any surge protection function, and only provides signal transmission capability.

In summary, the transmission circuit of the present invention can be automated and reduced in production cost compared to a transformer in a conventional Ethernet device. Furthermore, the transmission circuit of the present invention can provide necessary signal coupling and DC isolation, impedance matching and filtering common mode noise in Ethernet transmission to enhance the performance of signal transmission and provide surge protection.

The above embodiments are only used to illustrate the embodiments of the present invention, and to explain the technical features of the present invention, and are not intended to limit the scope of protection of the present invention. Any arrangement or change that is easily accomplished by those skilled in the art is within the scope of the invention.

1‧‧‧ Ethernet application circuit

11‧‧‧Ethernet connector

13‧‧‧Transmission circuit

13a‧‧‧Transmission component group

15‧‧‧Ethernet chip

Q1‧‧‧ first contact

Q2‧‧‧second contact

C1‧‧‧First Capacitor

C2‧‧‧second capacitor

G1‧‧‧first ground

G2‧‧‧second ground

L1‧‧‧First Inductor

L2‧‧‧second inductor

CS1‧‧‧First component group

CS2‧‧‧Second component group

T1‧‧‧ first transmission line

T2‧‧‧second transmission line

T3‧‧‧ third transmission line

T4‧‧‧ fourth transmission line

Claims (22)

A transmission circuit for an Ethernet network, comprising: four transmission component groups, each of the transmission component groups being coupled to an Ethernet chip and disposed inside an Ethernet connector or disposed on the The Ethernet connector is externally coupled to the Ethernet connector; wherein: each of the transmission component groups includes a first capacitor, a second capacitor, a first inductor, a second inductor, and a a first transmission line, a second transmission line, a third transmission line, a fourth transmission line, a first component group and a second component group; the first capacitor of each of the transmission component groups is connected in series with the first inductor, and Between the first transmission line and the second transmission line, the first capacitor is coupled to the Ethernet connector through the first transmission line, and the first inductor is coupled to the B through the second transmission line. The second capacitor is connected in series with the second inductor and coupled between the third transmission line and the fourth transmission line, and the second capacitor is coupled through the third transmission line. To the Ethernet connector to The second inductor is coupled to the Ethernet chip through the fourth transmission line; the first component group of each of the transmission component groups is coupled between the first transmission line and the third transmission line; and each of the transmissions The second component group of the component group is coupled between a first contact between the first capacitor and the first inductor and a second contact between the second capacitor and the second inductor. The transmission circuit of claim 1, wherein the first component group of each of the transmission component groups comprises a third inductor and a fourth inductor, the third inductor being coupled to the first transmission line and a first A grounding terminal is coupled between the third transmission line and the first grounding end. The transmission circuit of claim 2, wherein the first inductor and the second inductor are a common mode chock, one of the first inductor and one of the second inductor The inductance value is less than 10 microhenries (uH), the third inductor and the fourth inductor are a coupled inductor, and an inductance value of the third inductor and an inductance of the fourth inductor The value is greater than 15 microhenries (uH). The transmission circuit of claim 1, wherein the first component group of each of the transmission component groups comprises a third inductor, a fourth inductor, and a protection component, the third inductor and the fourth inductor The protection device is coupled between the first transmission line and the first transmission line. The protection element is coupled between the first inductor and the first inductor. The transmission circuit of claim 4, wherein the protection component is one of a semiconductor discharge tube, a varistor, a gas discharge tube, and a unidirectional transient suppression diode. The transmission circuit of claim 1, wherein the first component group of each of the transmission component groups comprises a first resistor and a second resistor, the first resistor being coupled to the first transmission line and a first A grounding terminal is coupled between the third transmission line and the first grounding end. The transmission circuit of claim 1, wherein the first component group of each of the transmission component groups includes a third capacitor and a fourth capacitor, the third capacitor being coupled to the first transmission line and a first ground terminal The fourth capacitor is coupled between the third transmission line and the first ground. The transmission circuit of claim 1, wherein the first component group of each of the transmission component groups comprises a third capacitor, a fourth capacitor, and a third inductor, and the third capacitor is connected in series with the fourth capacitor. And being coupled between the first transmission line and the third transmission line, the third inductor is coupled between a junction between the third capacitor and the fourth capacitor and a first ground. The transmission circuit of claim 1, wherein the first component group of each of the transmission component groups comprises a third capacitor, a fourth capacitor, a third inductor, and a fourth inductor in series, the third The capacitor is coupled to the first transmission line, the fourth capacitor is coupled to the third transmission line, and a contact between the third inductor and the fourth inductor is coupled to a first ground. The transmission circuit of claim 1, wherein the second component group of each of the transmission component groups comprises a bidirectional transient suppression diode coupled between the first contact and the second contact. The transmission circuit of claim 1, wherein the second component group of each of the transmission component groups comprises a first bidirectional transient suppression diode and a second bidirectional transient suppression diode, the first bidirectional transient The state suppression diode is coupled between the first contact and the second ground, and the second bidirectional transient suppression diode is coupled between the second contact and the second ground. The transmission circuit of claim 1, wherein the second component group of each of the transmission component groups comprises a first bidirectional transient suppression diode, a second bidirectional transient suppression diode, and a third inductor The first bidirectional transient suppression diode is connected in series with the second bidirectional transient suppression diode and coupled between the first contact and the second contact, and the third inductor is coupled to The first bidirectional transient suppression diode is between the one contact and the second ground end of the second bidirectional transient suppression diode. The transmission circuit of claim 1, wherein the second component group of each of the transmission component groups comprises: a first fast-reacting diode group, comprising two forward-connected fast-reacting diodes, and one of the two a contact is coupled to the first contact; a second fast-reacting diode set includes two fast-reacting diodes connected in series, and one of the contacts is coupled to the second contact; and The unidirectional transient suppression diode is coupled in parallel with the first fast reaction diode group and the second fast reaction diode group, and coupled to a second ground terminal. The transmission circuit of claim 1, wherein the second component group of each of the transmission component groups comprises: a third inductor; a first fast-reacting diode set comprising two fast-connecting diodes in a forward series a body, and one of the contacts is coupled to the first contact; a second fast-reacting diode set includes a fast-reacting diode of two forward series, and one of the contacts is coupled to the first a two-way contact; and a unidirectional transient suppression diode coupled in parallel with the first fast-reaction diode group and the second fast-reaction diode group, and coupled to the third inductor through the third inductor Second ground. The transmission circuit of claim 1, wherein the second component group of each of the transmission component groups includes a first resistor coupled between the first contact and the second contact. The transmission circuit of claim 1, wherein the second component group comprises a first resistor and a second resistor, the first resistor being coupled between the first contact and a second ground And the second resistor is coupled between the second contact and the second ground. The transmission circuit of claim 1, wherein the second component group of each of the transmission component groups includes a third capacitor coupled between the first contact and the second contact. The transmission circuit of claim 1, wherein the second component group of each of the transmission component groups comprises a third capacitor and a fourth capacitor, the third capacitor being coupled to the first contact and a second ground Between the terminals, and the fourth capacitor is coupled between the second contact and the second ground. The transmission circuit of claim 1, wherein the second component group of each of the transmission component groups comprises a third capacitor, a fourth capacitor, and a third inductor, and the third capacitor is connected in series with the fourth capacitor. And being coupled between the first contact and the second contact, the third inductor is coupled between a contact between the third capacitor and the fourth capacitor and a second ground. The transmission circuit of claim 1, wherein the second component group of each of the transmission component groups comprises a third capacitor, a fourth capacitor, a third inductor, and a fourth inductor in series, the third The capacitor is coupled to the first contact, the fourth capacitor is coupled to the second contact, and a contact between the third inductor and the fourth inductor is coupled to a second ground. The transmission circuit of claim 1, wherein the first capacitor and the second capacitor are a non-polar capacitor, and a capacitance value of one of the first capacitors and a capacitance value of the second capacitor is greater than or equal to 10 nanofarads (nF). The transmission circuit of claim 1, wherein the first inductor and the second inductor are a common mode chock, and an inductance value of the first inductor and the second inductor An inductance value is less than or equal to 10 microhenries (uH).