TWI739115B - Transmission line with filtering function - Google Patents

Abstract

The disclosure provides a transmission line with a filtering function. The transmission line includes a first electrical connector, a second electrical connector, a wire and a filtering device. The first electrical connector is configured to accommodate a first terminal and receive a first electrical signal through the first terminal. The wire is connected between the first terminal and the second electrical connector. The filtering device is disposed in the first electrical connector and electrically connected to the first terminal and the wire. The filtering device performs a filtering operation on the first electrical signal to provide a second electrical signal and transmits the second electrical signal to the second electrical connector through the wire.

Description

Transmission line with filtering function

The present invention relates to a transmission line, and particularly relates to a transmission line with filtering function.

In the prior art, transmission lines are often used to connect between different electronic components and to transmit electrical signals between these electronic components. In some applications, in addition to transmitting electrical signals to another electronic component through a transmission line, an electronic component may also transmit noise. Since the conventional transmission line does not have the ability to suppress noise, it is usually necessary to install a specific noise suppression component on the electronic component, so that the transmission performance of the electrical signal can not be affected by the noise.

Take the transmission line connected between the motherboard and the panel as an example. Since it does not have the ability to suppress noise, the motherboard needs to be equipped with an inductance/capacitor filter to prevent the noise from the motherboard from passing through the transmission line. Transfer to the panel. However, this approach cannot prevent the noise from the panel from being transmitted to the motherboard.

Therefore, for those skilled in the art, if a transmission line with a filtering function can be designed, the above problems will certainly be effectively improved.

In view of this, the present invention provides a transmission line with filtering function, which can be used to solve the above technical problems.

The present invention provides a transmission line with filtering function, including: a first electrical connection part, a second electrical connection part, at least one wire and a filtering device. The first electrical connection part is used for accommodating at least one first terminal and receiving a first electrical signal through the at least one first terminal. Each wire is connected between at least one of the first terminals and the second electrical connection part. The filter device is arranged at the first electrical connection part, and is electrically connected to each first terminal and each wire. The filtering device performs a filtering operation on the first electrical signal to provide a second electrical signal, and transmits the second electrical signal to the second electrical connection part through at least one wire.

Based on the above, the transmission line proposed by the present invention can perform filtering operations on the received first electrical signal through the filtering device provided therein, thereby achieving suppression/filtering of specific components (for example, noise) in the first electrical signal. Effect.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail in conjunction with the accompanying drawings.

Please refer to FIG. 1, which is a schematic diagram of a transmission line according to an embodiment of the present invention. In FIG. 1, the transmission line 100 is, for example, a cable that can be connected between electronic components, and is used to transmit signals such as SDIO and clock, but is not limited to this. As shown in FIG. 1, the transmission line 100 may include a first electrical connection portion 110, a second electrical connection portion 120, a wire 130 and a filter device 114.

In this embodiment, each wire 130 can be used to connect the first electrical connection portion 110 and the second electrical connection portion 120. More specifically, the first electrical connection portion 110 may be used to accommodate one or more first terminals (for example, the first terminal 112), and the second electrical connection portion 120 may be used to accommodate a second terminal corresponding to the aforementioned first terminal. A terminal (for example, the second terminal 122 corresponding to the first terminal 112), and each wire 130 can be used to connect the first terminal and the second terminal corresponding to each other. In the embodiment of the present invention, the first terminal and the second terminal mentioned are, for example, golden fingers well known to those with ordinary knowledge in the art, but the present invention is not limited to this.

For ease of description, the first terminal and the second terminal corresponding to each other can be referred to as a terminal pair. Based on this, the transmission line 100 of FIG. 1 can be regarded as including 5 terminal pairs, and the structure and operation mode of each terminal pair are the same. Therefore, the following description will only be based on a specific terminal pair composed of the first terminal 112 and the second terminal 122, and a person with ordinary knowledge in the art should be able to deduce the structure and operation of other terminal pairs.

In FIG. 1, each terminal pair can be configured with a corresponding filter device 114. Taking the above-mentioned specific terminal pair as an example, it may be configured with a filter device 114 electrically connected to the first terminal 112 and the wire 130. In an embodiment, the filter device 114 may be connected to the first terminal 112, but the invention is not limited to this.

In one embodiment, the transmission line 100 can be used to connect between two electronic components to suppress specific signal components (for example, miscellaneous components) from the electronic components connected to the first electrical connection portion 110 through the filter device in each terminal pair. News). Taking the above-mentioned specific terminal pair as an example, when the first electrical connection portion 110 is connected to a first electronic component (for example, a panel), the first electrical signal E1 from the first electronic component can be received through the first terminal 112. Afterwards, the filtering device 114 may perform a filtering operation on the first electrical signal E1 to provide a second electrical signal E2, and transmit the second electrical signal E2 through the wire 130 to a second electronic component (for example, a motherboard) connected to the second Electric connection part 120. More specifically, the second electrical signal E2 is transmitted to the second terminal 122 in the second electrical connection portion 120, but the present invention may not be limited to this. In other embodiments, the first electronic component may be a motherboard, and the second electronic component may be a panel or other devices, depending on the needs of the user. In addition, in some embodiments, the first electronic component and the second electronic component may be provided in the first electronic device and the second electronic device, respectively. In this case, the first electronic component may be disposed in the connection terminal of the first electronic device for connecting with the second electronic component of the second electronic device.

In one embodiment, the filtering device 114 can suppress the noise in the first electrical signal E1 through the aforementioned filtering operation to provide the second electrical signal E2. Specifically, the designer can adjust the relevant resonance characteristics of the filter device 114 to make the filter device 114 have low-pass, high-pass or stopband filter characteristics, so as to suppress the specific frequency in the first electrical signal E1. The effect of components (such as noise). In this way, the noise from the first electronic component (for example, the panel) will not be transmitted to the second electronic component (for example, the motherboard) connected to the second electrical connection portion 120 through the transmission line 100.

Please refer to FIG. 2, which is a structure diagram of a transmission line according to an embodiment of the present invention. In this embodiment, the transmission line 200 includes a first electrical connection portion 210, a second electrical connection portion 220, a wire 230, and a filter device 214.

Following the description in the previous embodiment, the transmission line 200 can be regarded as including 5 terminal pairs, and these terminal pairs are all equipped with corresponding filtering devices. Taking a specific terminal pair including the first terminal 212 and the second terminal 222 as an example, the filter device 214 may be configured.

In this embodiment, the filter device 214 is, for example, a microstrip line filter connected to the first terminal 212, which may include a capacitor portion 214a and an inductance portion 214b. It should be understood that the capacitance portion 214a and the inductance portion 214b are structures that can equivalently provide the functions of capacitors and inductors, rather than actual capacitors and inductors. In this case, when the first terminal 212 receives the first electrical signal from the electronic component, the filtering device 214 can filter the first electrical signal through the capacitor portion 214a and the inductance portion 214b to provide the second electrical signal. And the second electrical signal is transmitted to the second terminal 222 through the wire 230. In different embodiments, the patterns of the capacitor portion 214a and the inductance portion 214b can be designed according to the specific frequency to be suppressed (such as noise), and the pattern shown in FIG. 2 can be used to suppress the 2.4 GHz frequency band, for example. Noise, but the invention is not limited to this.

In order to prove the technical effect of the transmission line of the present invention, the following is further explained based on relevant experimental data.

Please refer to Figure 3A, Figure 3B and Figure 3C, where Figure 3A is a performance diagram of filtering by setting capacitors, Figure 3B is a performance diagram of filtering by setting capacitors and inductors connected in series, and Figure 3C is a through diagram 2 The performance diagram of the filtering in the embodiment.

In the scenario of Figure 3A, the filtering function is achieved through a capacitor with 12pF (and its parasitic inductance). From S(1,1) (ie, return loss) and S(2,1) (ie, penetration loss) shown in Figure 3A, it can be seen that only capacitors are used for filtering. Although the method can achieve a larger bandwidth, this bandwidth cannot be controlled and may cause undesirable results such as filtering out the fundamental frequency signal.

In the scenario of FIG. 3B, the filtering function is achieved through series-connected capacitors and inductors. From S(1,1) and S(2,1) shown in Fig. 3B, it can be seen that the use of series-connected capacitors and inductors to achieve the filtering function can achieve controllable bandwidth. However, due to the large size of the capacitors and inductors connected in series, they are not suitable for installation in general transmission lines.

In the scenario of FIG. 3C, the filtering function is realized through the filtering device 214 of FIG. 2. From S(1,1) and S(2,1) shown in Figure 3C, it can be seen that in addition to controlling the bandwidth of the filter device 214 in the required frequency band (for example, 2.4 GHz), its size is also suitable for Set in the general transmission line.

In addition, the performance of the transmission line of the embodiment of the present invention will not be affected by the length. Please refer to FIGS. 4A and 4B, where FIG. 4A is a transmission line performance diagram without a filter device, and FIG. 4B is a transmission line performance diagram using the transmission line of FIG. 2 to achieve a filtering function. In the scenarios of FIGS. 4A and 4B, the length of the wire used is, for example, 70 mm.

From the S(1,1) and S(2,1) shown in Figure 4A, it can be seen that for a transmission line without a filter device, it is almost impossible to achieve any suppression effect on the noise in the 2.4 GHz frequency band. On the other hand, from S(1,1) and S(2,1) shown in Figure 4B, it can be seen that the noise in the 2.4 GHz band has been effectively suppressed.

Please refer to FIGS. 5A and 5B again, where FIG. 5A is a transmission line performance diagram without a filter device, and FIG. 5B is a transmission line performance diagram using the transmission line of FIG. 2 to achieve a filtering function. In the scenarios of FIG. 5A and FIG. 5B, the length of the wire used is, for example, 100 mm.

From the S(1,1) and S(2,1) shown in Figure 5A, it can be seen that for a transmission line without a filter device, it is almost impossible to achieve any suppression effect on the noise in the 2.4 GHz frequency band. On the other hand, from the S(1,1) and S(2,1) shown in Figure 5B, it can be seen that the noise in the 2.4 GHz band can still be effectively suppressed. In other words, it can be seen from FIG. 4B and FIG. 5B that the performance of the transmission line proposed by the present invention is not affected by the wire length.

In addition, in order to prove that the bandwidth of the transmission line of the present invention can be adjusted according to requirements, the following is supplemented with FIG. 6, FIG. 7A, and FIG. 7B for explanation.

Please refer to FIG. 6, which is a partial structure diagram of the transmission line shown in the embodiment of FIG. 2. In this embodiment, the structure of the transmission line 600 is roughly the same as that of the transmission line 200 of FIG. 2, except that the patterns of the capacitor portion 614a and the inductance portion 614b in the filter device 614 have been adjusted accordingly to the 900 MHz frequency band considered. It is shown in the aspect, but the present invention is not limited to this.

Please refer to FIGS. 7A and 7B, where FIG. 7A is a transmission line performance diagram without a filter device, and FIG. 7B is a transmission line performance diagram using the transmission line of FIG. 6 to achieve a filtering function.

From the S(1,1) and S(2,1) shown in Fig. 7A, it can be seen that for a transmission line without a filter device, it is almost impossible to achieve any suppression effect on the noise in the 900 MHz frequency band. On the other hand, from S(1,1) and S(2,1) shown in Fig. 7B, it can be seen that noise in the 900 MHz frequency band can be effectively suppressed. In other words, it can be seen from FIG. 4B, FIG. 5B, and FIG. 7B that the bandwidth of the transmission line proposed by the present invention can be adjusted according to requirements.

In some embodiments, for a single terminal pair, the present invention can achieve simultaneous filtering of the first electrical signal by arranging multiple filtering devices (ie, microstrip line filters) connected to the first terminal. The effect of multiple frequency band signals.

Please refer to FIG. 8, which is a transmission line performance diagram in which a plurality of filter devices connected to the first terminal are arranged in a single terminal pair. In this embodiment, it is assumed that a certain terminal pair of the transmission line of the present invention is provided with three microstrip line type filters connected to the first terminal, and each of them can be designed to suppress 850 MHz, 1.940 GHz, and 2.450 GHz. Noise in equal frequency bands. It can be seen from S(1,1) and S(2,1) of FIG. 8 that the transmission line of the present invention can effectively suppress the signals in the above-mentioned frequency bands.

In other embodiments, for a transmission line that uses a differential line for transmission, the present invention also proposes a solution to provide a filtering function by arranging a filtering device therein. This will be further explained below.

Please refer to FIG. 9, which is a schematic diagram of a transmission line according to an embodiment of the present invention. In FIG. 9, the transmission line 900 is, for example, a cable that can be connected between electronic components, and can be used to transmit signals such as PCIe, USB, EDP, and MIPI. As shown in FIG. 9, the transmission line 900 may include a first electrical connection portion 910, a second electrical connection portion 920, wires 930a, 930b, and a filter device 914.

In this embodiment, the wires 930a and 930b can form a differential wire pair and can be used to transmit differential signals between the first electrical connection portion 910 and the second electrical connection portion 920. As shown in FIG. 9, the first terminals in the first electrical connection portion 910 can be arranged in pairs, and can be connected to the second electrical connection portion 920 through a corresponding differential line pair. For example, the paired first terminals 912a and 912b in the first electrical connection portion 910 can be connected to the paired second terminals 922a and 922b in the second electrical connection portion 920 through wires 930a and 930b, respectively.

For ease of description, the first terminal and the second terminal connected through a differential line pair can be referred to as a differential terminal pair. It can be seen that the transmission line 900 of FIG. 9 can be regarded as including five differential terminal pairs, and the structure and operation mode of each differential terminal pair are the same. Therefore, the following description will be based only on the specific differential terminal pair composed of the first terminals 912a, 912b, and the second terminals 922a and 922b, and those with ordinary knowledge in the art should be able to deduce the structure and operation of other differential terminal pairs. Way.

In Figure 9, each differential terminal pair can be configured with a corresponding filter device. Taking the above-mentioned specific differential terminal pair as an example, it may be configured with a filter device 914 electrically connected to the first terminals 912a, 912b, and the wires 930a and 930b. In an embodiment, the filtering device 914 may be connected to the first terminals 912a and 912b, but the invention may not be limited thereto.

In one embodiment, the transmission line 900 can be used to connect between two electronic components to suppress specific signal components from the electronic components connected to the first electrical connection portion 910 (for example, Noise). Taking the above-mentioned specific differential terminal pair as an example, when the first electrical connection portion 910 is connected to a first electronic component (for example, a panel), the first electrical signal from the first electronic component can be received through the first terminals 912a and 912b E1. After that, the filtering device 914 may perform a filtering operation on the first electrical signal E1 to provide a second electrical signal E2, and transmit the second electrical signal E2 to a second electronic component (for example, a motherboard) through the wires 930a and 930b. The second electrical connection portion 920. More specifically, the second electrical signal E2 is transmitted to the second terminals 922a and 922b in the second electrical connection portion 920, but the present invention may not be limited to this.

In one embodiment, the filtering device 914 can suppress the noise in the first electrical signal E1 through the aforementioned filtering operation to provide the second electrical signal E2. For example, the first electrical signal E1 in this embodiment may include a differential mode signal and a common mode signal, and the common mode signal therein can be regarded as noise in the first electrical signal E1 and can be suppressed by the filtering device 914 /Filter out. Specifically, the designer can adjust the relevant resonance characteristics of the filter device 914 to make the filter device 914 have the characteristics of a low-pass, high-pass, or band-rejection filter, so as to suppress specific frequency components (such as impurities) in the first electrical signal E1. News) effect. In this way, the noise from the first electronic component (for example, the panel) will not be transmitted to the second electronic component (for example, the motherboard) connected to the second electrical connection portion 920 through the transmission line 900.

Please refer to FIGS. 10A and 10B, where FIG. 10A is a structure diagram of a transmission line according to an embodiment of the present invention, and FIG. 10B is a perspective view of the first electrical connection part according to FIG. 10A. In this embodiment, the transmission line 1000 includes a first electrical connection portion 1010, a second electrical connection portion 1020, wires 1030a, 1030b, and a filter device 1014.

Following the description in the previous embodiment, the transmission line 1000 can be regarded as including five differential terminal pairs, and these differential terminal pairs are all equipped with corresponding filtering devices. Taking a specific differential terminal pair including the first terminals 1012a, 1012b, and the second terminals 1022a and 1022b as an example, the filter device 1014 may be configured.

In this embodiment, the filtering device 1014 may include a microstrip line type filter 10141 and a coupling element 10142. The microstrip line type filter 10141 may be connected to the first terminals 1012a and 1012b, and may include a capacitor part 10141a and an inductance part. 10141b. The coupling element 10142 can be electrically connected to the first terminals 1012a and 1012b. In this case, when the first terminals 1012a and 1012b receive the first electrical signal from the electronic component (which includes, for example, a differential mode signal and a common mode signal), the filter device 1014 can couple the common mode signal to the coupled signal through a coupling method. Element 10142. After that, the filter device 1014 can perform a filtering operation through the capacitor portion 10141a and the inductance portion 10141b to provide the second electrical signal. More specifically, the filtering device 1014 can filter the common mode signal through the above filtering operation to provide the second electrical signal including only the differential mode signal. After that, the filter device 1014 can transmit the second electrical signal to the second terminals 1022a and 1022b through the wires 1030a and 1030b.

In different embodiments, in accordance with the specific frequency to be suppressed (such as noise), the patterns of the capacitor portion 10141a and the inductance portion 10141b can be designed accordingly, and the pattern shown in FIG. 10B can be used to suppress the 2.4 GHz frequency band, for example. Noise, but the invention is not limited to this.

In order to prove the technical effect of the transmission line of the present invention, the following is further explained based on relevant experimental data. Please refer to FIG. 11A, which is a differential mode performance diagram of the transmission line shown in FIGS. 10A and 10B. In this embodiment, the curve 1110 is, for example, the S21dd curve (ie, differential mode attenuation) when the filter device 1014 is provided in the transmission line 1000, and the curve 1120 is, for example, the S21dd when the filter device of the present invention is not provided in the transmission line. curve.

It can be seen from FIG. 11A that the attenuation shown by the curve 1110 is generally not higher than that of the curve 1120, which shows that the transmission line 1000 proposed by the present invention can maintain (or even improve) the transmission performance of the differential mode signal.

Please refer to FIG. 11B again, which is based on the transmission line common mode performance diagram shown in FIG. 10A and FIG. 10B. In this embodiment, the curve 1130 is, for example, the S21cc curve (ie, common mode attenuation) when the filter device 1014 is provided in the transmission line 1000, and the curve 1140 is, for example, the S21cc curve when the filter device of the present invention is not provided in the transmission line. curve.

It can be seen from FIG. 11B that, compared to the curve 1140, the curve 1130 exhibits a significant attenuation at 2.4 GHz (ie, the dotted line frame), which shows that the transmission line 1000 proposed by the present invention can be used to suppress noise in the 2.4 GHz frequency band (ie, Common mode signal).

In summary, the transmission line proposed in the present invention can filter the received first electrical signal through the filtering device (for example, a microstrip line filter) provided therein, so as to suppress/filter the first electrical signal. The effect of certain components in the signal (for example, noise). In addition, for a transmission line that uses a differential line for transmission, the present invention also proposes a solution to provide a filtering function by providing a filtering device (which includes, for example, a coupling element and a filter in the form of a microstrip line) in the transmission line.

Thereby, the noise from the first electronic component (for example, the panel) connected to the first electrical connection part will not be transmitted to the second electronic component (for example, motherboard).

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the relevant technical field can make some changes and modifications without departing from the spirit and scope of the present invention. The protection scope of the present invention shall be subject to those defined by the attached patent application scope.

100, 200, 600, 900, 1000‧‧‧ transmission line 110, 210, 910, 1010‧‧‧First electrical connection part 112, 212, 912a, 912b, 1012a, 1012b‧‧‧First terminal 114, 214, 614, 914, 1014‧‧‧Filtering device 120, 220, 920, 1020‧‧‧Second electrical connection part 122, 222, 922a, 922b, 1022a, 1022b‧‧‧Second terminal 130, 230, 930a, 930b, 1030a, 1030b‧‧‧Wire 214a, 614a, 10141a‧‧‧Capacitor 214b, 614b, 10141b‧‧‧Inductance part 10141‧‧‧Microstrip line form filter 10142‧‧‧Coupling element 1110, 1120, 1130, 1140‧‧‧curve E1‧‧‧First electrical signal E2‧‧‧Second electrical signal

FIG. 1 is a schematic diagram of a transmission line according to an embodiment of the present invention. FIG. 2 is a diagram showing the structure of a transmission line according to an embodiment of the present invention. Fig. 3A is a graph showing the effectiveness of filtering by setting a capacitor. FIG. 3B is an efficiency diagram of filtering by setting capacitors and inductors connected in series. FIG. 3C is a graph showing the performance of filtering through the embodiment of FIG. 2. FIG. 4A is a performance diagram of a transmission line without a filter device. FIG. 4B is a performance diagram of a transmission line using the transmission line of FIG. 2 to achieve a filtering function. FIG. 5A is a performance diagram of a transmission line without a filter device. FIG. 5B is a performance diagram of a transmission line using the transmission line of FIG. 2 to achieve a filtering function. FIG. 6 is a partial structure diagram of the transmission line according to the embodiment of FIG. 2. FIG. 7A is a performance diagram of a transmission line without a filter device. FIG. 7B is a performance diagram of a transmission line using the transmission line of FIG. 6 to achieve a filtering function. FIG. 8 is a transmission line performance diagram in which a plurality of filter devices connected to the first terminal are arranged in a single terminal pair. FIG. 9 is a schematic diagram of a transmission line according to an embodiment of the present invention. FIG. 10A is a structure diagram of a transmission line according to an embodiment of the present invention. FIG. 10B is a perspective view of the first electrical connection part shown in FIG. 10A. FIG. 11A is a diagram showing the differential mode performance of the transmission line shown in FIG. 10A and FIG. 10B. FIG. 11B is a diagram showing the common mode performance of the transmission line shown in FIG. 10A and FIG. 10B.

100‧‧‧Transmission line

110‧‧‧First electrical connection part

112‧‧‧First terminal

114‧‧‧Filtering device

120‧‧‧Second electrical connection part

122‧‧‧Second terminal

130‧‧‧Wire

E1‧‧‧First electrical signal

E2‧‧‧Second electrical signal

Claims (7)

A transmission line with a filtering function includes: a first electrical connection portion, wherein the first electrical connection portion is used for accommodating at least one first terminal, and receives a first electrical signal through the at least one first terminal, wherein the The transmission line is a row of wires; a second electrical connection portion; at least one wire, wherein each of the wires is connected between one of the at least one first terminal and the second electrical connection portion; and a filter device disposed on the second electrical connection portion An electrical connection part is electrically connected to each of the first terminals and each of the wires, wherein the filter device performs a filtering operation on the first electrical signal to provide a second electrical signal, and transmits the second electrical signal through the At least one wire is transmitted to the second electrical connection part, wherein the filter device includes a microstrip line filter connected to the at least one first terminal, and the filter device includes a plurality of filters connected to the at least one first terminal. A microstrip line form filter, the first electrical connection portion receives the first electrical signal through the at least one first terminal, and the filtering device performs the filtering operation on the first electrical signal through the microstrip line form filters to Suppress multiple noises in the first electrical signal, and provide the second electrical signal. The transmission line according to claim 1, wherein the filter device includes a capacitor portion and an inductance portion connected in series with each other, the first electrical connection portion receives the first electrical signal through the at least one first terminal, and The filtering device performs the filtering operation on the first electric signal through the capacitance part and the inductance part to provide the second electric signal. According to the transmission line described in claim 1, wherein the filtering device suppresses a noise in the first electrical signal through the filtering operation to provide the second electrical signal. The transmission line according to claim 1, wherein the first electrical signal includes a differential mode signal and a common mode signal, and the filter device further includes: a coupling element electrically connected to the at least one first terminal, The common mode signal is coupled to the coupling element through a coupling method. The transmission line according to claim 4, wherein the filtering device filters the common mode signal through the filtering operation to provide the second electrical signal including only the differential mode signal. According to the transmission line described in claim 1, wherein the first electrical connection part is connected to an electronic component, and receives the first electrical signal from the electronic component. According to the transmission line described in item 6 of the scope of patent application, the electronic component includes a panel, and the second connecting portion is connected to a motherboard.

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