Grounding optimization for unmasked data connections

Abstract

The invention relates to ground optimization for unmasked data connections. The unshielded data connection is disposed on a first surface of a printed circuit board having a main plane. The unmasked data connections are provided in an imaginary plane perpendicular to the surface of the printed circuit board, the imaginary plane including the unmasked data connections as line segments in the imaginary plane. One or more grounding connections are symmetrically arranged around the unshielded data connection. The arrangement is symmetrical with respect to an imaginary plane.

Description

[0001] Cross - Reference to Related Applications

[0002] This disclosure claims priority to U.S. Non - Provisional Patent Application 18 / 985,837, filed on December 18, 2024, and U.S. Provisional Patent Application No. 63 / 612,335, filed on December 19, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to unshielded data connections in high - interference networks such as automotive networks. More specifically, this disclosure relates to grounding techniques for reducing interference on unshielded data connections. Background Art

[0004] The background description provided herein is for the purpose of generally presenting the background of the disclosure. To the extent that the work of the inventors is described in this background section, such work is not, either expressly or by implication, admitted as prior art with respect to the subject matter of the disclosure.

[0005] In the automotive industry, unshielded twisted - pair (UTP) cables are commonly used to communicate with physical - layer transceiver (PHY) system - on - chip (SoC) devices with speeds up to 1 Gbps. UTP cables are also frequently used in switch SoC devices with integrated PHY ports with speeds up to 1000BT1. A media - dependent interface (MDI) is used to physically connect these devices to the UTP cable. The MDI serves as a connection point between the device and the transmission medium (such as copper cable or optical fiber).

[0006] The MDI is a physical interface that connects a device to a transmission medium for data communication, such as a copper wire, optical fiber, or wireless channel. The MDI serves as a critical boundary where the electrical or optical signals generated by the device are adapted to propagate through the selected transmission medium. The MDI is an integral part of a communication system, which is typically designed to conform to established standards (such as IEEE 802.3 for Ethernet) to ensure compatibility and interoperability between different devices.

[0007] MDI is defined by its physical connector, electrical or optical signal specifications, and impedance matching capabilities. MDI is typically equipped with mechanisms to handle specific media challenges, such as electromagnetic interference in copper-based systems or modal dispersion in fiber optic systems. In addition to signal transmission, MDI can also incorporate signal conditioning functions (such as amplification, filtering, or equalization) to maintain data integrity over various distances and media types. Depending on the application, MDI can also include protection circuits, grounding devices, and isolation mechanisms to protect the equipment from transient voltages, surges, or ground loops. These interfaces play a crucial role in enabling reliable and efficient data transmission in wired and wireless communication systems.

[0008] Grounding of MDI (especially in network systems such as Ethernet) is crucial for maintaining performance, reliability, and safety. Proper grounding can ensure that electrical interference and signal integrity issues are minimized.

[0009] The MDI grounding connection scheme has a significant impact on the electromagnetic interference performance of automotive networks with UTP cable channels. Unshielded cable channels (i.e., UTP cables) behave differently in terms of grounding compared to shielded cables and require careful optimization. If implemented improperly, MDI grounding can have a negative impact on UTP cables. The interaction between MDI grounding and UTP cables affects the sensitivity of UTP cables to noise. Improper grounding of MDI can introduce common-mode noise into UTP cables. Since UTP cables lack shielding, they are more vulnerable to noise if grounding is not managed properly. This noise can degrade the differential signals transmitted through the twisted pair, resulting in errors or reduced data rates.

[0010] MDI grounding also affects ground loops. Ground loops occur when there is a potential difference between the grounds of interconnected devices, forming an unexpected loop of current flow. For UTP cables, ground loops can interfere with signals because the cable has no shielding to isolate the twisted pair from external electrical interference. Summary of the Invention

[0011] Systems and methods for providing ground optimization for unshielded data connections in automotive networks are described herein. The unshielded data connection can be a pair of differential signal traces disposed on a first surface of a printed circuit board (PCB) that has a main plane. The pair of differential signal traces is disposed within an imaginary plane that is perpendicular to the surface of the PCB and includes the differential signal traces as line segments within the imaginary plane. One or more symmetrically arranged grounding connections are disposed around the pair of differential signal traces. The arrangement is symmetric with respect to the imaginary plane.

[0012] For an even number of ground connections, the first half of the ground connections can be disposed on one side of a hypothetical plane, while the second half of the ground connections can be disposed on the other side of the hypothetical plane. For an odd number of ground connections, the first half of the ground connections of the even subset of the odd number of ground connections can be disposed on the first surface of the PCB on one side of the hypothetical plane, and the second half of the ground connections of the even subset is disposed on the first surface of the PCB on the other side of the hypothetical plane. For the remaining number of ground connections, the first ground connection is disposed at a position on the second surface of the PCB that intersects the hypothetical plane. The remaining number of ground connections (i.e., an even number of ground connections) is disposed on the second surface of the PCB and is symmetrically distributed with respect to the hypothetical plane.

[0013] In some embodiments, the PCB is a multi-layer PCB. A single ground connection can be disposed at a position on the inner layer of the PCB that intersects the hypothetical plane. An even number of ground connections that are symmetrically distributed with respect to the hypothetical plane can be disposed on the inner layer of the PCB. An odd number of ground connections can be disposed on the inner layer of the PCB, where the first ground connection is disposed at a position that intersects the hypothetical plane, and the remaining even number of ground connections is symmetrically distributed with respect to the hypothetical plane.

[0014] The ground connection can be a solid ground plane, one or more metal strips, one or more zero-ohm resistors, or one or more capacitors. In each of these embodiments, the ground connections are symmetrically distributed with respect to the hypothetical plane. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In conjunction with the accompanying drawings, after considering the following detailed description, further features, its nature, and various advantages of the present disclosure will be apparent, where like reference numerals always denote like components, and:

[0016] Figure 1 is a schematic diagram of an MDI connection having a symmetric arrangement of ground connections for a plurality of differential signal trace pairs according to some embodiments of the subject matter of the present disclosure;

[0017] Figure 2 is a schematic diagram of an MDI connection having a second symmetric arrangement of ground connections for a plurality of differential signal trace pairs according to some embodiments of the subject matter of the present disclosure;

[0018] Figure 3 is a schematic diagram of an MDI connection having a symmetric arrangement of ground connections and additional asymmetric ground connections for a plurality of differential signal trace pairs according to some embodiments of the subject matter of the present disclosure;

[0019] Figure 4 is a schematic diagram of an MDI connection having different symmetric arrangements of ground connections for different differential signal trace pairs according to some embodiments of the subject matter of the present disclosure;

[0020] Figure 5 A schematic diagram of an MDI connection with a symmetric arrangement of ground connections for multiple different signal trace pairs from different signal sources, according to some embodiments of the subject matter of the present disclosure;

[0021] Figure 6 A schematic diagram of an odd number of symmetrically arranged ground connections disposed on different surfaces of a printed circuit board, according to some embodiments of the subject matter of the present disclosure;

[0022] Figure 7 A schematic diagram of an even number of symmetrically arranged ground connections disposed on different surfaces of a printed circuit board, according to some embodiments of the subject matter of the present disclosure;

[0023] Figure 8 A schematic diagram of a second symmetric arrangement of an odd number of ground connections disposed on different surfaces of a printed circuit board, according to some embodiments of the subject matter of the present disclosure;

[0024] Figure 9 A schematic diagram of an odd number of symmetrically arranged ground connections disposed on different surfaces of a printed circuit board and within at least one inner layer, according to some embodiments of the subject matter of the present disclosure; and

[0025] Figure 10 A flowchart representing an illustrative process of using symmetrically arranged ground connections to shield differential signal trace pairs, according to some embodiments of the subject matter of the present disclosure. Detailed Description

[0026] Currently, MDI ground optimization is rarely performed. Due to the lack of optimization, current UTP MDI grounds degrade the performance of UTP channels in terms of electromagnetic interference and electrostatic discharge tolerance. This can lead to failures, especially in switch systems that typically have multiple integrated PHYs.

[0027] By providing methods and systems for ground optimization for unshielded data connections to MDI ports, the performance of the data connections in terms of electromagnetic interference and electrostatic discharge tolerance is greatly improved, thus making automotive networks more robust.

[0028] This document describes a ground optimization solution where critical grounds are applied symmetrically around each differential signal trace pair connected to an MDI port. The ground connections are placed close to the differential signal trace pair's ground, although the distance of any given ground connection may depend on the number and specific arrangement of the ground connections. For example, in an arrangement of 2 ground connections, each ground connection can be placed within 2 millimeters of the differential signal trace pair. In an arrangement of 4 ground connections, the ground connections can be placed farther from the differential signal trace pair as long as the ground connections can still provide a shielding effect for the differential signal trace pair. The ground connections can be solid plane connections, metal strips, or zero-ohm resistors. For AC ground solutions, capacitors can also be used.

[0029] For a solid ground plane, each ground connection is set at a position on the PCB where it intersects a virtual plane that is perpendicular to the main plane of the PCB and includes the differential signal trace pair as a line segment within the plane. In one embodiment, an uninterrupted (e.g., solid) ground plane can be set in the inner layer of a multi-layer PCB. At least a portion of the solid ground plane can be set on either side of the virtual plane such that there are substantially an infinite number of ground connections on either side of the virtual plane. Thus, this setting of the solid ground plane is a symmetric arrangement of ground connections. For other types of ground connections (e.g., zero-ohm resistors), the symmetric arrangement depends on the number of ground connections used. For a single ground connection, the grounding element (e.g., zero-ohm resistor) is set in a similar manner to the solid ground plane connection, where the grounding element is set at a position on the PCB where it intersects a hypothetical plane.

[0030] For an even number of ground connections, the grounding elements can be set at positions on both sides of a hypothetical plane on the PCB in a symmetric distribution. For example, if two grounding elements are used, one grounding element can be set on one side of the hypothetical plane, at a specific distance (e.g., 1 mm) from the differential signal trace pair, while the second grounding element can be set on the other side of the hypothetical plane, at the same distance from the differential signal trace pair. In some embodiments, the PCB can be a multi-layer PCB. The grounding elements (e.g., metal strips) can be set in the inner layer of the PCB. Thus, one or more grounding elements can be set in the inner layer of the PCB. For example, if four grounding elements are used, two grounding elements can be set on both sides of the hypothetical plane as described above. The third grounding element can be set at a position on the opposite surface of the PCB where it intersects the hypothetical plane. The fourth grounding element can be set at a position in the inner layer of the PCB where it intersects the hypothetical plane. Other symmetric arrangements and other numbers of grounding elements are possible, and all of these are within the scope of this disclosure.

[0031] For an odd number of ground connections, at least one ground connection can be set at a position intersecting with a hypothetical plane. Then, the remaining even number of ground connections can be arranged symmetrically and evenly distributed on both sides of the hypothetical plane.

[0032] Figure 1 FIG. 4 is a schematic diagram of an MDI connection with symmetric ground connections having a plurality of differential signal trace pairs according to some embodiments of the present disclosure. A signal source 100 is disposed on a PCB 102. Differential signal trace pairs 104, 106, 108, and 110 respectively transmit signals from the signal source 100 to MDI ports 112, 114, 116, and 118.

[0033] The differential signal trace pairs 104, 106, 108, and 110 are unshielded and vulnerable to electromagnetic interference. In addition, wires 128, 130, 132, and 134 are unshielded twisted pairs of a UTP cable connected to the MDI ports 112, 114, 116, and 118. This UTP cable is also vulnerable to electromagnetic interference. Through the ground connections, each differential signal trace pair is protected from at least some electromagnetic interference.

[0034] Ground connections play a crucial role in ensuring signal integrity, device protection, and system reliability. Ground connections provide a stable electrical reference point for signal transmission and reception, mitigate the effects of electromagnetic interference, reduce noise, and prevent voltage imbalances that may compromise the integrity of data signals. The use of ground connections can also protect connected devices from transient electrostatic discharges (such as electrical surges) by safely diverting excessive current away from sensitive circuits. A multi-point grounding scheme is commonly used in high-frequency systems (such as automotive electronics) to reduce impedance. The ground connections can all be connected to a common ground plane or to a common ground (not shown) through wires or traces.

[0035] To obtain optimal performance, the ground connections are arranged symmetrically around each differential signal trace pair. Ground connections 120a and 120b are disposed on both sides of a hypothetical plane perpendicular to the surface of the PCB 102, in which the differential signal trace pair 104 forms a line segment. Similarly, ground connections 122a and 122b are disposed around the differential signal trace pair 106, ground connections 124a and 124b are disposed around the differential signal trace pair 108, and ground connections 126a and 126b are disposed around the differential signal trace pair 110.

[0036] The signal source 100 is disposed in the first region 136 of the PCB 102. The region 136 may include a first ground plane of digital logic disposed on the PCB 102. The MDI ports 112, 114, 116, and 118 are disposed in the second region 138 of the PCB 102. The region 138 may include a second ground plane for cable connections via the MDI ports. A discontinuity 140 on the surface of the PCB 102 or in the ground plane layer is used for electrical isolation between the region 136 and the region 138. The discontinuity 140 may be formed, for example, by etching or otherwise removing a portion of the metal layer to create a gap between different ground regions.

[0037] Figure 2 is a schematic diagram of an MDI connection having a second symmetric arrangement of ground connections for a plurality of differential signal trace pairs, in accordance with some embodiments of the subject matter of the present disclosure. In this arrangement, the ground connections 200, 202, 204, and 206 are arranged to protect the differential signal trace pairs 104, 106, 108, and 110, respectively. The ground connections 200, 202, 204, and 208 are solid ground planes. Each of the ground connections 200, 202, 204, and 206 is disposed at a location where it intersects a hypothetical plane perpendicular to the surface of the PCB 102, and the corresponding differential signal trace pair forms a line segment in this hypothetical plane. By being disposed at these locations, with half of its width on either side of the hypothetical plane, each ground connection is symmetrically distributed with respect to the hypothetical plane.

[0038] Figure 3 is a schematic diagram of an MDI connection in accordance with some implementations of the subject matter of the present disclosure, having a symmetric ground connection arrangement for a plurality of differential signal trace pairs and additional asymmetric ground connections. In some implementations, the PCB may be affected by divergent transient noise currents or electrostatic discharges. To better shield the differential signal trace pairs, at least one additional ground connection 300 may be disposed on the PCB 102. The ground connection 300 may be disposed asymmetrically with respect to the differential signal trace pairs. In Figure 3 one example shown, a single ground connection 300 is disposed near the edge of the PCB 102. Other numbers and locations of ground connections are possible.

[0039] Figure 4 is a schematic diagram of an MDI connection having different symmetric arrangements of ground connections for different differential signal trace pairs, in accordance with some embodiments of the subject matter of the present disclosure. The signal source 100 is disposed on the PCB 102. The differential signal trace pairs 104, 106, 108, and 110 respectively transmit signals from the signal source 100 to the MDI ports 112, 114, 116, and 118. The differential signal trace pairs 104, 106, 108, and 110 are unshielded and vulnerable to electromagnetic interference.

[0040] The cable 404 is an unshielded twisted pair cable and is vulnerable to electromagnetic interference. The wires 128, 130, and 132 are respectively connected from the cable 404 to the MDI ports 112, 114, and 116. However, the wire 134, which is connected from its cable 406 to the MDI port 402, is a shielded twisted pair cable and is less vulnerable to electromagnetic interference compared to the unshielded twisted pair cable. For example, the wire 134 is shielded by a shield 408 within the cable 406. Thus, the ground connections for shielding the differential signal trace pair 110 can be optimized for a shielded twisted pair cable. In one example, the differential signal trace pairs 104, 106, and 108 are respectively shielded using two ground connections 120a-b, 122a-b, and 124a-b. On the other hand, the differential signal trace pair 110 is shielded by four ground connections 400a-d, which have electrical characteristics optimized for a channel using a shielded twisted pair cable. For example, the shielding effectiveness of an STP cable may be 60 dB, which means it can reduce interference by a factor of 1,000. The ground connections can be configured to provide sufficient shielding only against interference that may exceed the shielding effectiveness of the STP cable. In contrast, a UTP cable does not provide additional shielding beyond that provided by twisting the wire pairs within the cable and requires the ground connections to be configured to effectively resist higher levels of interference.

[0041] In some embodiments, the MDI connection (of which the MDI ports 112, 114, 116, and 118 are a part) can carry data from multiple sources. Figure 5 is a schematic diagram of an MDI connection according to some embodiments of the subject matter of the present disclosure, which has symmetrically arranged ground connections for a plurality of different signal trace pairs from different signal sources. In this example, the differential signal trace pairs 104, 106, and 108 are connected to a first signal source 500, while the differential signal trace pair 110 is connected to a second signal source 502. Even though the signal sources are different, each differential signal trace pair is still shielded using symmetrically arranged ground connections as described above.

[0042] Figures 6 - 8 Shows different symmetric arrangements for both an even number and an odd number of ground connections for differential signal trace pairs. Different arrangements can be achieved by setting the ground connections on different surfaces of the PCB in the area around the differential signal trace pairs. The distance between the differential signal trace pairs and the ground connections changes the effective shielding level provided by the ground connections. Thus, the placement of the ground connections in a symmetric arrangement of ground connections affects the overall effectiveness of the symmetric arrangement of ground connections.

[0043] Figure 6Schematic diagram of an odd number of symmetrically arranged ground connections disposed on different surfaces of a printed circuit board, according to some embodiments of the present disclosure theme. Figure 6 Depicts two opposite surfaces 604 and 610 of the PCB. A signal source 600 and a differential signal trace pair 602 are disposed on the first surface 604 of the PCB. Ground connections 606 and 608 are also disposed on the surface 604 and are symmetrically arranged on both sides of an imaginary plane perpendicular to the surface 604, the imaginary plane including the differential signal trace pair 602 as a line segment within the imaginary plane. On the opposite surface 610 of the PCB, a ground connection 612 is also symmetrically disposed with respect to the imaginary plane, that is, the imaginary plane intersects the ground connection 612 at its midpoint such that half of the ground connection 612 is disposed on both sides of the imaginary plane.

[0044] Figure 7 Schematic diagram of an even number of symmetrically arranged ground connections disposed on different surfaces of a printed circuit board, according to some embodiments of the present disclosure theme. Figure 7 Depicts two opposite surfaces 704 and 710 of the PCB. A signal source 700 and a differential signal trace pair 702 are disposed on the first surface 704 of the PCB. Ground connections 706 and 708 are also disposed on the surface 704 and are symmetrically arranged on both sides of an imaginary plane perpendicular to the surface 704, the imaginary plane including the differential signal trace pair 702 as a line segment within the imaginary plane. On the opposite surface 710 of the PCB, ground connections 712 and 714 are also symmetrically arranged on both sides of the imaginary plane. The distance between the ground connection 712 and the ground connection 714 does not have to be the same as the distance between the ground connection 706 and the ground connection 708, as long as each pair of ground connections is symmetrically disposed with respect to the imaginary plane or symmetrically disposed with respect to a part of the differential signal trace pair forming a line segment within the imaginary plane.

[0045] Figure 8 Schematic diagram of a second symmetric arrangement of an odd number of ground connections disposed on different surfaces of a printed circuit board, according to some embodiments of the present disclosure theme. Figure 8 Depicts two opposite surfaces 804 and 810 of the PCB. A signal source 800 and a differential signal trace pair 802 are disposed on the first surface 804 of the PCB. Ground connections 806 and 808 are also disposed on the first surface 804 and are symmetrically arranged on both sides of an imaginary plane perpendicular to the surface 804, the imaginary plane including the differential signal trace pair 802 as a line segment within the imaginary plane. On the opposite surface 810 of the PCB, ground connections 812, 814, and 816 are also symmetrically disposed on both sides of the imaginary plane, that is, the imaginary plane intersects the ground connection 814 at its midpoint such that half of the ground connection 814 is disposed on both sides of the imaginary plane. The ground connections 812 and 816 are disposed at equidistant positions on both sides of the imaginary plane. AndFigure 7 As in the example of, the distance between the ground connection 812 and the ground connection 816 does not have to be the same as the distance between the ground connection 806 and the ground connection 808, as long as each pair of ground connections is symmetrically arranged with respect to the imaginary plane, or symmetrically arranged with respect to a part of the differential signal trace pair forming a line segment in the imaginary plane.

[0046] Figure 9 FIG. 5 is a schematic diagram of an odd number of symmetrically arranged ground connections disposed on different surfaces of a printed circuit board and within at least one inner layer, according to some embodiments of the present disclosure. A signal source 900 and a differential signal trace pair 902 are disposed on a first surface 904 of the PCB. Ground connections 906 and 908 are also disposed on the first surface 904 and are symmetrically arranged on both sides of an imaginary plane 910 perpendicular to the surface 904, the imaginary plane including the differential signal trace pair 902 as a line segment within the imaginary plane. Then, a ground connection 912 is disposed at a position within the inner layer 914 of the PCB such that the imaginary plane 910 intersects the ground connection 912 at its midpoint, and half of the ground connection 912 is disposed on both sides of the imaginary plane. On the opposite surface 916 of the PCB, ground connections 918 and 920 are also symmetrically arranged with respect to the imaginary plane 910. The distance between the ground connection 918 and the ground connection 920 does not have to be the same as the distance between the ground connection 906 and the ground connection 808, as long as each pair of ground connections is symmetrically arranged with respect to the imaginary plane 910.

[0047] Figure 10 FIG. 9 is a flow chart illustrating an illustrative process of using symmetrically arranged ground connections to shield a differential signal trace pair, according to some embodiments of the present disclosure. At 1002, a counter variable N is initialized to an initial value of 1. The variable T D is also initialized to represent the number of differential signal trace pairs for which ground connections must be provided in a corresponding symmetric arrangement.

[0048] At 1004, the variable T G is initialized to represent the number of ground connections to be arranged symmetrically around the Nth differential signal trace pair. At 1006, it is determined whether the remainder obtained by dividing T G by 2 is equal to 1, using, for example, a modulo function, to determine whether T G is odd.

[0049] If at 1006 T G is odd ("yes"), then at 1008, a first ground connection is disposed at a position intersecting an imaginary plane (the imaginary plane including the Nth differential signal trace pair as a line segment within the imaginary plane). Then, at 1010, the value of the variable H is set to half of the remaining number of ground connections (i.e., the number of ground connections remaining after subtracting 1 from T)G Half of small 1). If T G is even (at 1006, it is "No"), then at 1012, set the value of H to half of T G .

[0050] At 1014, set H ground connections to the first side of the imaginary plane. Also set H ground connections to the second side of the imaginary plane. Each pair of ground connections can be set on the same PCB surface as the Nth differential signal trace pair, or arranged on opposite surfaces of the PCB.

[0051] At 1016, determine whether N is equal to T D , which means that the ground connections have been set in a symmetric arrangement for all differential signal trace pairs. If N is not equal to T D (at 1016, it is "No"), then at 1018, increase the value of N by 1, and the process returns to 1004. If N is equal to T D (at 1016, it is "Yes"), then the process ends.

[0052] Thus, a method and system for shielding differential signal trace pairs that communicate to couple one or more signal sources and one or more media-related interface ports in an automotive network have been provided.

[0053] As used herein and in the following claims, the structure "one of A and B" shall mean "A or B".

[0054] It should be noted that the foregoing only illustrates the principles of the present invention, and the present invention can be practiced through other embodiments in addition to the illustrated embodiments. The illustrated embodiments are for illustrative purposes only and not for limiting purposes, and the present invention is only limited by the following claims.

Claims

1. A communication hub device in a car network, the communication hub device comprising: one or more ports, each port being communicatively coupled to a signal source through a corresponding pair of differential signal traces and having a medium dependent interface, wherein the differential signal trace pairs are subject to electromagnetic interference or electrostatic discharge; as well as For each corresponding differential signal trace pair, the corresponding symmetrically arranged ground connection is configured to shield the corresponding differential signal trace pair from the electromagnetic interference and electrostatic discharge.

2. The communication hub device of claim 1, wherein each of the corresponding differential signal trace pairs is disposed on a first surface of a printed circuit board.

3. The communication hub device of claim 2, wherein the corresponding symmetrically arranged ground connections include a solid ground plane disposed on the second surface of the printed circuit board.

4. The communication hub device of claim 2, wherein the printed circuit board is a multi-layer printed circuit board, and wherein the corresponding symmetrically arranged ground connections include a solid ground plane disposed on an inner layer of the printed circuit board.

5. The communication hub device of claim 1, wherein: Each of the respective differential signal trace pairs is disposed on a first surface of a printed circuit board having a main plane, each respective differential signal trace pair is disposed in a respective imaginary second plane, the respective imaginary second plane includes the respective differential signal trace pair as a line segment in the respective imaginary second plane, the respective imaginary second plane being perpendicular to the main plane; as well as The corresponding symmetrically arranged ground connections include an even number of ground connections arranged on the first surface, a first half of the ground connections are arranged on a first side of the corresponding corresponding imaginary second plane, and a second half of the ground connections are arranged on a second side of the corresponding corresponding imaginary second plane.

6. The communication hub device of claim 5, wherein a line drawn through the centers of all of the ground connections is perpendicular to the corresponding differential signal trace pairs.

7. The communication hub device of claim 5, wherein the even number of ground connections comprises only two ground connections.

8. The communication hub device of claim 1, wherein: Each corresponding differential signal trace pair is disposed on a first surface of a printed circuit board having a main plane, each corresponding differential signal trace pair is disposed in a corresponding imaginary second plane, the corresponding imaginary second plane includes the corresponding differential signal trace pair as a line segment in the corresponding imaginary second plane, the corresponding imaginary second plane is perpendicular to the main plane; and The corresponding symmetrically arranged ground connections include an odd number of ground connections, wherein a subset of the ground connections including an even number of ground connections is arranged on the first surface, wherein a first half of the even number of ground connections is arranged on the first side of the corresponding corresponding imaginary second plane, and a second half of the even number of ground connections is arranged on the second side of the corresponding corresponding imaginary second plane, and a remaining number of ground connections are arranged on a second surface of the printed circuit board opposite to the first surface, wherein a first ground connection of the remaining number of ground connections is arranged at a position on the second surface intersecting with the corresponding corresponding imaginary second plane, and a remaining part of the remaining number of ground connections is symmetrically distributed relative to the corresponding corresponding imaginary second plane.

9. The communication hub device of claim 1, wherein each ground connection comprises a metal strip.

10. The communication hub device of claim 1, wherein each ground connection comprises a zero ohm resistor.

11. The communication hub device of claim 1 , wherein each ground connection comprises a capacitor.

12. The communication hub device of claim 1, further comprising one or more additional ground connections configured to shield the differential signal trace pair from transient noise.

13. The communication hub device of claim 1, further comprising a second signal source, wherein at least one of the one or more ports is communicatively coupled to the second signal source.

14. The communication hub device of claim 1, wherein a first corresponding symmetrically arranged ground connection is different in configuration than a second corresponding symmetrically arranged ground connection.

15. A communication hub device according to claim 1, wherein each of the corresponding differential signal trace pairs is arranged on a first surface of a multi-layer printed circuit board (PCB), at least one of the corresponding symmetrically arranged ground connections is arranged on a second surface of the multi-layer printed circuit board opposite to the first surface, and at least one of the corresponding symmetrically arranged ground connections is arranged on an inner layer of the multi-layer printed circuit board.

16. A method of shielding a differential signal trace pair, the differential signal trace pair communicatively coupling a signal source and a medium-dependent interface port in an automotive network, the differential signal trace pair being disposed on (a) a first surface of a printed circuit board having a primary plane, and (b) within an imaginary plane, the imaginary plane (i) including the differential signal trace pair as line segments in the imaginary plane, and (ii) being perpendicular to the primary plane, the method comprising: One or more ground connections are disposed in a symmetrical arrangement around the differential signal trace pair.

17. The method of claim 16, wherein the one or more ground connections include an even number of ground connections, and wherein arranging the one or more ground connections in a symmetrical arrangement around the differential signal trace pair includes: disposing a first half of the one or more ground connections on a first side of the imaginary plane; and A second half of the one or more ground connections is disposed on a second side of the imaginary plane.

18. The method of claim 16, wherein the one or more ground connections include an odd number of ground connections, and wherein arranging the one or more ground connections in a symmetrical arrangement around the differential signal trace pair includes: on the first surface, disposing a first half of a subset of ground connections on a first side of the imaginary plane, the subset of ground connections comprising an even number of ground connections; On the first surface, disposing a second half of the subset of ground connections on a second side of the plane; On a second surface of the printed circuit board opposite to the first surface, disposing a first ground connection of the remaining number of ground connections at a position on the second surface that intersects the imaginary plane; as well as On the second surface, a remaining portion of the remaining number of ground connections is provided, distributed symmetrically with respect to the imaginary plane.

19. The method of claim 16, wherein the printed circuit board is a multi-layer printed circuit board, and wherein providing one or more ground connections in a symmetrical arrangement around the differential signal trace pair comprises: A ground connection of the one or more ground connections is disposed in an inner layer of the multilayer printed circuit board at a location on the inner layer that intersects the imaginary plane.

20. The method of claim 16, wherein the printed circuit board is a multi-layer printed circuit board, and wherein providing one or more ground connections in a symmetrical arrangement around the differential signal trace pair comprises: In an inner layer of the multilayer printed circuit board, an even number of ground connections of the one or more ground connections are arranged symmetrically with respect to the imaginary plane.

21. The method of claim 16, wherein the printed circuit board is a multi-layer printed circuit board, and wherein providing one or more ground connections in a symmetrical arrangement around the differential signal trace pair comprises: placing a first ground connection of the one or more ground connections in an inner layer of the multilayer printed circuit board at a location on the inner layer that intersects the imaginary plane; and An even number of the one or more ground connections are provided in the inner layer of the multilayer printed circuit board, symmetrically distributed with respect to the imaginary plane.

22. The method of claim 16, wherein providing one or more ground connections in a symmetrical arrangement around the differential signal trace pair comprises: A solid ground plane is disposed at a position intersecting the imaginary plane.

23. The method of claim 16, wherein providing one or more ground connections in a symmetrical arrangement around the differential signal trace pair comprises: One or more pairs of metal strips are arranged symmetrically with respect to the imaginary plane.

24. The method of claim 16, wherein providing one or more ground connections in a symmetrical arrangement around the differential signal trace pair comprises: One or more zero-ohm resistors are provided which are symmetrically distributed with respect to the imaginary plane.

25. The method of claim 16, wherein providing one or more ground connections in a symmetrical arrangement around the differential signal trace pair comprises: One or more capacitors are provided which are symmetrically distributed with respect to the imaginary plane.

Images