Multi-tap transmission line system and method

Abstract

Various embodiments relating to a multitap transmission line are described herein. This multitap transmission line system may have a first end and at least one second end, the transmission line having a corresponding characteristic impedance value (Zc), the first end having a corresponding first end impedance which is the same as the characteristic impedance, at least one second end having a corresponding at least one second end impedance which is the same as the characteristic impedance, at least two tap circuits connected to the transmission line, each tap circuit having a tap port, each tap port having a corresponding tap impedance value (Zo). The characteristic impedance value Zc is lower than, in some cases considerably lower than, each tap impedance value Zo.

Description

Description of Related Applications

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 458967, filed on April 13, 2023, and the entire contents of U.S. Provisional Patent Application No. 63 / 458967 are hereby incorporated by reference in their entirety.

Technical Field

[0002] The various embodiments described herein generally relate to waveguides connected to a network for a wireless terminal and methods thereof.

Background Art

[0003] FIG. 1A is a schematic diagram showing a plurality of devices or nodes communicating wirelessly with each other using a conventional method known in the prior art. A plurality of devices such as a high-throughput Wi-Fi transceiver 101 are communicating with each other through a wireless network 102. However, communication through the wireless network 102 can cause numerous constraints and interfering factors. Examples of those constraints and interfering factors include propagation variability, spectrum availability, interference, and potential attacks by cyber threats.

[0004] On the other hand, other baseband serial communications such as high-throughput Peripheral Component Interconnect Express (PCIe) and Ethernet local area network are more robust and are not affected by the constraints and interfering factors found in wireless networks, but they can only function in two-point communication and require data switches and extensive wiring, thus causing significant problems related to design, manufacturing, installation costs, and interconnects.

Summary of the Invention

Problems to be Solved by the Invention

[0005] Particularly in high-node-density networks, there is a need for improved solutions that can overcome the shortcomings of wireless networks such as Wi-Fi and baseband data switching networks such as PCIe, while maintaining the advantages of these technologies. [Means for solving the problem]

[0006] In at least one embodiment, a multi-tap transmission line is provided. In at least one embodiment, the multi-tap transmission line comprises a first end and at least one second end, the transmission line having a corresponding characteristic impedance value (Zc), the first end having a corresponding first end impedance, the first end impedance being the same as the characteristic impedance, the at least one second end having a corresponding at least one second end impedance, the corresponding at least one second end impedance being the same as the characteristic impedance, and at least two tap circuits connected to the transmission line, each tap circuit comprising a tap port, each tap port having a corresponding tap impedance value (Zo), the characteristic impedance value Zc being lower than each tap impedance value Zo.

[0007] In at least one embodiment, the multi-tap transmission line further comprises, for each tap circuit, a first resistive element corresponding to a first port of the tap circuit and having a corresponding first resistance value, a second resistive element corresponding to a second port of the tap circuit and having a second resistance value, a corresponding tap device connected to the corresponding tap port, and a tap resistive element corresponding to the tap port and having a tap resistance value (Rt), wherein the first and second resistance values ​​are substantially equal to a series resistance value (Rs), and the first resistive element, the second resistive element, and the tap resistive element are connected at a connection point in a T-shape configuration.

[0008] In at least one embodiment, the tap device is selected from the group consisting of an output RF transmitter, an input RF receiver, an RF transceiver that serves as both input and output, an RC transceiver, multiple RF transceivers, a test port of a vector network analyzer (VNA), a test port of a time-domain reflectivity measurement (TDR) analyzer, a tap point of another multi-tap transmission line, any RF device, and a termination.

[0009] In at least one embodiment, the first and second end impedances remain matched to the transmission line when the tap device is connected to a multi-tap transmission line.

[0010] In at least one embodiment, the transmission line includes a distributor configuration, and at least one second end includes two second ends. In at least one embodiment, the multitap transmission line is mounted as a rigid printed circuit board. In at least one embodiment, the multitap transmission line is mounted as individual flexible printed circuit boards. In at least one embodiment, the multitap transmission line is constructed as a flexible printed circuit board with adhesive tape. In at least one embodiment, the multitap transmission line is constructed in a branch configuration.

[0011] In at least one embodiment, the multitap transmission line operates with at least one tap device disconnected, short-circuited, or damaged. In such an embodiment, the multitap transmission line operates with the remaining tap devices.

[0012] In at least one embodiment, the first and second resistive elements have corresponding series resistance values ​​of about 0 ohms.

[0013] In at least one embodiment, a method for optimizing a multi-tap transmission line is provided. In at least one embodiment, the method includes the steps of: determining an optimal characteristic impedance value (Zc) for each corresponding tap impedance value (Zo) and for the total number of tap ports in the transmission line; and determining a series resistance value (Rs) and a tap resistance value (Rt) based on the optimal characteristic impedance value (Zc) such that the loss between the first tap circuit and the last tap circuit is minimized.

[0014] In at least one embodiment, the step of determining the optimal characteristic impedance value (Zc) is to select a candidate impedance value selected from a range of values ​​between 0 and the termination impedance value; and for each candidate impedance value: the step of determining the worst-case insertion loss between the first tap circuit and the last tap circuit based on the candidate impedance value and the tap impedance value corresponding to the tap port, wherein the worst-case insertion loss is determined based on the determination of the longitudinal insertion loss and the transverse insertion loss according to the following formula: TTLN[dB]=TIL(1)+LIL(2)+LIL(3)+...+LIL(j)+...LIL(N-1)+TIL(N); where LIL is the longitudinal insertion loss value determined according to LIL(j)=20LOG10(1-Zc / 2Zo(j)), where j is a range of values ​​indicating the tap index from 2 to (N-1), and N is the total number of tap ports; where TIL is the lateral insertion loss value determined according to TIL(j)=10LOG10(Zc / 4Zo(j)), where j is 1 or N; and the formula includes the step of determining the optimal characteristic impedance value (Zc) based on candidate impedance values ​​that minimize the worst-case insertion loss.

[0015] In at least one embodiment, the series resistance (Rs) is, TIFF2026513982000002.tif11114

[0016] It is determined according to the formula, where Zo(j) is the tap impedance value of tap port j, j is a range of values ​​indicating the tap index ranging from 1 to N, N represents the total number of tap ports, and Zc is the optimal characteristic impedance value.

[0017] In at least one embodiment, the tap resistance value (Rt) is, TIFF2026513982000003.tif11114

[0018] It is determined according to the formula, where Zo(j) is the tap impedance value of tap port j, j is a range of values ​​indicating the tap index ranging from 1 to N, N represents the total number of tap ports, and Zc is the optimal characteristic impedance value.

[0019] In at least one embodiment, the method further includes the step of selecting an alternative characteristic impedance value (Zc) from a range between -30% and +30% of the optimal characteristic impedance value.

[0020] In at least one embodiment, the step of determining the optimal characteristic impedance value (Zc) is as a function of candidate impedance values: This is performed using graph analysis, which involves plotting the loss function following TTLN(Zc)=TIL(1)+LIL(2)+LIL(3)+...+LIL(j)+...LIL(N-1)+TIL(N) and selecting the optimal characteristic impedance value based on the candidate impedance value corresponding to the minimum value of the loss function.

[0021] In at least one embodiment, a multi-tap transmission line for use in an automobile vehicle is provided.

[0022] In at least one embodiment, a multi-tap transmission line comprises a first end and at least one second end, the transmission line having a corresponding characteristic impedance value (Zc), the first end having a corresponding first end impedance which is the same as the characteristic impedance, the at least one second end having a corresponding at least one second end impedance which is the same as the characteristic impedance, and at least two tap circuits are connected to the transmission line, each tap circuit comprising a tap port, each tap port having a corresponding tap impedance value (Zo), the characteristic impedance value Zc being lower than each tap impedance value Zo. In at least one embodiment, the multi-tap transmission line further comprises, for each tap circuit, a first resistive element corresponding to a first port of the tap circuit and having a corresponding first resistance value, a second resistive element corresponding to a second port of the tap circuit and having a second resistance value, a corresponding tap device connected to the corresponding tap port, and a tap resistive element corresponding to the tap port and having a tap resistance value (Rt), wherein the first and second resistance values ​​are substantially equal to a series resistance value (Rs), and the first resistive element, the second resistive element, and the tap resistive element are connected at a connection point in a T-shape configuration.

[0023] In at least one embodiment, the multitap transmission line further comprises at least 24 tap devices. In at least one embodiment, the tap devices are selected from the group consisting of vehicle sensors, engine control units (ECUs), gateways, and AI nodes. In at least one embodiment, the multitap transmission line is constructed as a flexible printed circuit board having adhesive tape. In at least one embodiment, the multitap transmission line further comprises secondary multitap transmission lines to provide redundancy. In at least one embodiment, the tap devices switch from the multitap transmission line to the secondary multitap transmission line.

[0024] In at least one aspect, a multi-tap transmission line for use in a remotely operated vehicle (ROV) is provided. In at least one embodiment, the tap device is selected from the group consisting of an ROV sensor, an ROV engine control unit (ECU), an ROV gateway, and an ROV AI node. In at least one embodiment, the multi-tap transmission line is constructed in a branched configuration. In at least one embodiment, the multi-tap transmission line includes a resistive power divider for branching the multi-tap transmission line into a plurality of lines.

[0025] In at least one aspect, a multi-tap transmission line for use in a server rack is provided. In at least one embodiment, the tap device is a server.

[0026] In at least one aspect, a multi-tap transmission line for use in a plurality of processor chips in an inter-chip configuration is provided. In at least one embodiment, the multi-tap transmission line is external to the plurality of processor chips and is connected to nodes within the plurality of processor chips. In at least one aspect, the multi-tap transmission line is implemented as a rigid printed circuit board. In at least one embodiment, the multi-tap transmission line is implemented as an individual flexible printed circuit board. In at least one aspect, the multi-tap transmission line is implemented on at least one of a silicon substrate for a chip, a chiplet, and an interposer.

Brief Description of the Drawings

[0027] To better understand the various embodiments described herein and to more clearly show how these various embodiments may be implemented, by way of example, at least one exemplary embodiment is shown and reference is made to the accompanying drawings described hereinafter. The drawings are not intended to limit the scope of the teachings described herein. [Figure 1A] Schematic diagram showing a plurality of devices communicating wirelessly with each other using conventional methods known in the prior art [Figure 1B] A schematic diagram showing multiple devices communicating with each other using a multi-tap transmission line according to an embodiment. [Figure 2] Block diagram of an embodiment of a multi-tap transmission line [Figure 3] Block diagram of an embodiment of a branched multi-tap transmission line [Figure 4] Schematic diagram of a tap configuration for a multi-tap transmission line. [Figure 5] Schematic diagram of an embodiment of a multi-tap transmission line [Figure 6] This plot shows the dependence of the tap resistance (Rt) and series resistance (Rs) on the characteristic impedance (Zc) of a multi-tap transmission line. [Figure 7] Plot showing the dependence of longitudinal insertion loss (LIL) and transverse insertion loss (TIL) on the characteristic impedance (Zc) of a multi-tap transmission line. [Figure 8] A plot showing the dependence of the worst-case insertion loss (TTLN) on the characteristic impedance (Zc) of a multi-tap transmission line and the number of taps N in the transmission line. [Figure 9] A plot showing the dependence of the worst-case insertion loss (TTLN) on the characteristic impedance (Zc) of a multi-tap transmission line and the number of taps N in the transmission line. [Figure 10] Plot showing the frequency dependence of S1-24 for the case of four samples. [Figure 11] Plot showing the frequency dependence of SL-L for the case of four samples. [Figure 12] Front perspective view of an embodiment of a rack-mounted planar multi-tap transmission line. [Figure 13] Rear perspective view of an embodiment of a rack-mounted planar multitap transmission line (Figure 12) [Figure 14] Diagram showing the layered structure used in the manufacture of printed circuit boards. [Figure 15] Rear perspective view of a tap in a planar multi-tap transmission line. [Figure 16] Figure 15 shows the features on the outer layer of the tap and a front perspective view of the via structure. [Figure 17] Detailed view of 230B in Figure 15 [Figure 18] Enlarged view of the active conductive characteristics of the tap in Figure 15. [Figure 19] Detailed view of 230D in Figure 18 [Figure 20] Figure 18 shows a close-up view of the details identified as 230E. [Figure 21] Schematic diagram of the tap model in Figure 15 [Figure 22] Plot of the model's S-parameters in Figure 21. [Figure 23] Schematic diagram of a planar multi-tap transmission line model in Figure 13. [Figure 24] Figure 23 shows the frequency dependence of the S-parameters of the model. [Figure 25] Schematic diagram of a backplane multitap transmission line [Figure 26] Perspective view of an embodiment of a coaxial multi-tap transmission line. [Figure 27] Detailed view of 300A in Figure 26 [Figure 28] Perspective view of an embodiment of a coaxial stack with a coaxial tap, two coaxial standoffs, and a coaxial termination. [Figure 29] Figure 28: Exploded view of the coaxial stack. [Figure 30] Front perspective view of a coaxial tap [Figure 31] Detailed view of 321A in Figure 30 (enlarged view) [Figure 32] Figure 30 shows a magnified view of the PCB active conductivity characteristics of the coaxial tap. [Figure 33] Figure 32 shows the rear view of the PCB active conductive features of the coaxial tap. [Figure 34] Figure 33 shows a close-up view of the details identified as 321B. [Figure 35] Front perspective view of the PCB conductive characteristics of the coaxial tap in Figure 30. [Figure 36] Rear view of the PCB conductive characteristics of the coaxial tap in Figure 35. [Figure 37] Front perspective view of the coaxial cable termination. [Figure 38]Rear view of the coaxial cable termination (Figure 37) [Figure 39] Perspective view of the PCB conductivity characteristics of the coaxial termination in Figure 37. [Figure 40] Detailed view of 330C in Figure 38 [Figure 41] Top perspective view of an embodiment of a coaxial connector adapter [Figure 42] Bottom view of the coaxial connector adapter embodiment shown in Figure 41. [Figure 43] Figure 41 is an exploded view of an embodiment of the coaxial connector adapter. [Figure 44] Figure 41 is an exploded view of an embodiment of the coaxial connector adapter. [Figure 45] Schematic diagram of a coaxial tap model. [Figure 46] Figure 45 shows the frequency dependence of the S-parameters of the model. [Figure 47] Schematic diagram of a coaxial multi-tap transmission line model. [Figure 48] Figure 47 shows the frequency dependence of the S-parameters of the model. [Figure 49] Schematic diagram showing frequency division multiplex access tap devices, time division multiplex access tap devices, and composite tap devices. [Figure 50] Schematic diagram showing a redundant multi-tap transmission line system. [Figure 51] Schematic diagram showing the bridging of a multi-tap transmission line. [Figure 52] Schematic diagram showing a multi-tap transmission line equipped with a narrowband coupler and taps. [Figure 53] A schematic diagram showing a multi-tap transmission line system applied to automotive applications. [Figure 54] A schematic diagram showing a multi-tap transmission line system in a branched configuration applied to drone applications. [Figure 55] Schematic diagram of a power distributor used in the branching configuration of a multi-tap transmission line. [Figure 56] Schematic diagram of a multi-tap transmission line system applied to server racks. [Figure 57]Schematic diagram of a multi-tap transmission line detailing connection point 5622 in Figure 56. [Figure 58] Simplified diagram of a 3-layer AI network [Figure 59] Schematic diagram of the AI ​​network in Figure 58 implemented with multi-tap transmission lines [Modes for carrying out the invention]

[0028] The following describes various apparatuses or processes to illustrate examples of embodiments of the inventions described in each claim. None of the embodiments described below are intended to limit the claimed inventions, and the claimed inventions may encompass processes or apparatuses different from those described below. The claimed inventions are not limited to apparatuses or processes having all the features of any one of the apparatuses or processes described below, or to features common to some or all of the apparatuses or processes described below. Any apparatus or process described below may not be an embodiment of any claimed invention. Inventions disclosed in apparatuses or processes not claimed in this document may be the subject of other means of protection, such as a continuing patent application, and the applicant, inventor, or rights holder has no intention of abandoning, denying, or attributing such inventions to the public by the disclosure in this document.

[0029] Furthermore, in order to ensure the conciseness and clarity of the illustrations, reference numbers may be repeated between drawings to indicate corresponding or similar elements, where deemed appropriate. In addition, many specific details are provided to allow for a full understanding of the embodiments described herein. However, those skilled in the art will understand that the embodiments described herein can be implemented without these specific details. In other instances, well-known methods, procedures, and components are not described in detail so as not to obscure the embodiments described herein. Moreover, the descriptions herein should not be construed as limiting the scope of the embodiments described herein.

[0030] The following detailed descriptions are illustrative and not intended to limit the embodiments and uses described in this application. As used herein, the terms “exemplary” or “explanatory” mean “serving as an example, case, or explanation.” Any implementation described herein as “exemplary” or “explanatory” should not necessarily be construed as being preferable or advantageous to other implementations. All implementations described below are illustrative and provided to enable those skilled in the art to practice the disclosure, and are not intended to limit the scope of the appended claims. Furthermore, there is no intention to be bound by the prior art, background, summary, or any explicit or implicit theory presented in the following detailed description.

[0031] Furthermore, it should be noted that the terms “combined” or “bonded” as used herein may have several different meanings depending on the context in which they are used. For example, the terms “combined” or “bonded” may have mechanical, electrical, or communication connotations. For instance, as used herein, the terms “combined” or “bonded” may, depending on the specific context, indicate that two elements or devices can be directly connected to each other, or that they can be connected to each other via one or more intermediate elements or devices through electrical elements, electrical signals, optical signals, or mechanical elements.

[0032] Furthermore, as used herein, the expression “and / or” is intended to represent an inclusive “or.” That is, for example, “X and / or Y” is intended to mean either X or Y, or both X and Y. As yet another example, “X, Y and / or Z” is intended to mean either X or Y or Z, or any combination thereof.

[0033] Furthermore, as used herein, terms expressing degree, such as “substantially,” “about,” and “approximately,” mean that there is a reasonable degree of deviation in the modified item, provided that the final result does not change significantly. These terms may also be interpreted to include deviations of the modified item such as 1%, 2%, 5%, or 10%, provided that this deviation does not negate the meaning of the modified item.

[0034] Furthermore, descriptions of numerical ranges by endpoints in this specification include all numerical values ​​and their fractions within that range (for example, the range from 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.90, 4, and 5). Also, all numerical values ​​and their fractions are presumed to be modified by the term “approximately,” which means a variation of a certain amount from the numerical value mentioned, such as 1%, 2%, 5%, or 10%, within a range where the final result does not change significantly.

[0035] Throughout this specification, any reference to “one embodiment,” “embodiment,” “at least one embodiment,” or “several embodiments” means, in particular, that one or more specific features, structures, or characteristics may be combined in any suitable manner in one or more embodiments, unless otherwise specified as incompatible or an alternative option.

[0036] Similarly, throughout this specification and the appended claims, the term “communicative” in variations such as “communication path,” “communication coupling,” and “communicatively coupled” is used to generally refer to any technical arrangement for transferring and / or exchanging information. Examples of communication paths include, but are not limited to, electrical conduction paths (e.g., conductive wires, physiological signal conduction), electromagnetic radiation paths (e.g., radio waves, optical signals, etc.), or any combination thereof. Examples of communication coupling include, but are not limited to, electrical coupling, magnetic coupling, radio coupling, optical coupling, or any combination thereof.

[0037] Some of the exemplary embodiments of systems, devices, or methods described in accordance with the teachings of this Spectrum may be implemented as a combination of hardware or software. For example, some of the embodiments described herein may be implemented in at least some cases using one or more computer programs running on one or more programmable devices which include at least one processing element and at least one data storage element (including volatile and / or non-volatile memory). Depending on the nature of the device, these devices may also include at least one input device (e.g., a keyboard, mouse, touch panel, input pins, input port, etc. for providing at least one input such as an input signal) and at least one output device (e.g., a display screen, printer, wireless radio, output port, output pin, etc. for providing at least one output such as an output signal).

[0038] It should also be noted that there will be some elements used to implement at least some of the embodiments described herein, which may be implemented through software written in a high-level procedural language such as object-oriented programming. The program code may be written in C, C++, or any other suitable programming language and may consist of modules or classes, as is well known to experts in object-oriented programming. Alternatively, or in addition to, some of these elements implemented through software may be written in assembly language, machine code, or firmware, as necessary.

[0039] At least some of the software programs used to implement at least one of the embodiments described herein may be stored in a storage medium or device readable by a general-purpose or special-purpose programmable device. When read by a programmable device (sometimes referred to as a computer device), the software program code configures the programmable device to operate in a novel, specific, and predefined manner in order to perform at least one of the methods described herein.

[0040] Furthermore, at least some of the programs relating to the systems and methods of the embodiments described herein may be distributed as computer program products including computer-readable media containing computer-available instructions, such as program code for one or more processors. The program code may be pre-installed and incorporated at the time of manufacture and / or installed later as an update to an already deployed computer system. The media may be provided in a variety of forms, including, but not limited to, one or more diskettes, compact disks, tapes, memory chips, and non-temporary forms such as magnetic and electronic storage devices. In another embodiment, the media may be temporary in nature, including, but not limited to, wired transmission, satellite transmission, internet transmission (e.g., download), media, digital and analog signals, etc. Computer-available instructions may also be in a variety of formats, including compiled and uncompiled code.

[0041] Any module, unit, component, server, computer, terminal, or computer device described herein and that executes software instructions in accordance with the teachings herein may include, or have access to, computer-readable media such as storage media, computer storage media, or data storage devices (removable and / or non-removable), such as magnetic disks, optical disks, or tapes. Computer storage media may include volatile and non-volatile, removable and non-removable media, comprising any method or technique for storing information, such as computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disk (DVD) or other optical storage media, magnetic cassettes, magnetic tapes, magnetic disk storage devices or other magnetic storage devices, or any other media that can be used to store desired information and are accessible by applications, modules, or both. Any such computer storage media may be part of a device, or accessible or connectable to that device.

[0042] It should be noted that the term "combined" as used herein refers to two elements that are either directly combined with each other or combined with each other through one or more intermediate elements.

[0043] The following technical and semantic classifications are provided in the context of the various embodiments disclosed herein: (1) The terms radio and radio frequency (RF) are used interchangeably. (2) The RF transceiver is the front end of the RF terminal. (3) Terminal is an abbreviation for data terminal. (4) A tap device is connected to a tap port, and an RF terminal is a subclass of a tap device. (5) Wi-Fi is a representative technology of the wireless class that supports multipoint connections. (6) PCIe (PCI Express) is a representative technology for wired two-point connections. (7) MTL is an acronym for multi-tap transmission line. (8) PMTL is an acronym for Planar Multitap Transmission Line. (9) bPMTL is an acronym for backplane planar multitap transmission line. (10) CMTL is an acronym for Coaxial Multitap Transmission Line. (11) In the schematic diagram, the strings in square brackets such as [Rs] and [Zc] represent the parameter values ​​of that particular circuit element. (12) LAN is an acronym used for Local Area Network. (13) TRX is an acronym for transceiver. (14) AI is an acronym for artificial intelligence.

[0044] Currently, in systems with multiple devices, methods for connecting one device to another can be implemented using wireless or wired networking technologies such as Wi-Fi links and PCIe links. Wireless links such as Wi-Fi links offer the ability to connect a large number of devices or nodes in a multipoint network, but can be limited by certain drawbacks such as propagation variability, spectral availability, interference, and potential attacks by cyber threats. On the other hand, wired baseband communication systems such as PCIe and Ethernet links offer high throughput, but their connectivity is limited by two-point physical links that require data switches and excessive wiring.

[0045] In one experiment, the performance of PCIe and Wi-Fi data links was compared. Both data links used the same 8GHz medium. The 8GHz frequency constraint is defined by the performance of currently available PCB cards and connectors for PCIe transmission at 16Gbps. Note that 8GHz is the Nyquist frequency for 16Gbps NRZ (non-zero return) signals and reflects the sine wave frequency required to transmit a binary sequence (10101...) at a maximum data transfer rate of 16Gbps. Furthermore, the 8GHz constraint coincides with the maximum frequency of 7.125GHz used by WiFi-7 transceivers. In this experiment, a point-to-point transmission line with an 8GHz bandwidth was constructed, equipped with either Wi-Fi or PCIe transceivers at both ends. For the experiment, transmission line impedance and mode were ignored.

[0046] Using this 8GHz transmission line, PCIe was found to transmit at (1) 16Gbps with a standard PCIe transceiver, or (2) 32Gbps with a PCIe transceiver modified to use the PAM4 modulation scheme, a technology introduced for PCIe-6.

[0047] On the same transmission line, WiFi-7 was found to transmit 46 Gbps using (1) one standard transceiver per endpoint on one 320 MHz channel, (2) 138 Gbps using a combination of three standard transceivers per endpoint to utilize all three available 320 MHz channels for WiFi-7, or (3) 1150 Gbps using a combination of 25 modified transceivers per endpoint to utilize 25 x 320 MHz channels (these transceivers are modified to use the entire 8 GHz spectrum, as they are no longer limited by certain constraints imposed while operating in true radio mode).

[0048] Based on this experiment, we can conclude that Wi-Fi technology enables efficient use of transmission lines and offers a competitive alternative to PCIe.

[0049] To balance the advantages and disadvantages of Wi-Fi and PCIe technologies, multitap transmission lines are proposed and disclosed in various embodiments herein. Multitap transmission lines replace air as the propagation medium for wireless terminals, thereby preventing limitations and disruptive factors prevalent in wireless communication, such as propagation variability, spectral availability, interference, or potential attacks. Furthermore, multitap transmission lines provide the reliability of wired links. Thus, the multitap transmission lines disclosed herein offer the advantages of multipoint connectivity for wireless transceivers.

[0050] A multitap transmission line having the ability to communicate couple multiple devices, as shown in Figure 1B, is provided herein. The multitap transmission line 100 provides a propagation medium 103 that can introduce the flexibility of multipoint connectivity, such as that of a wireless transceiver, and the reliability of a wired link, while reducing the constraints and obstacles prevalent in wireless communication. The multitap transmission line can provide a broadband RF transmission line using waveguides and taps to connect multiple radio frequency terminal devices and create a data network on which those terminal devices can communicate. In at least one embodiment, an optimized broadband RF multitap transmission line is provided, which can couple with multiple RF terminals to create a data network. The transmission line can be constructed as a series of terminated tap circuits, each containing a resistive element and the transmission line.

[0051] Methods for optimizing multi-tap transmission lines are also provided herein. In at least one embodiment, a method for optimizing multi-tap transmission lines is used to determine the characteristic impedance of the multi-tap transmission line and the values ​​of the resistive elements of the tap circuit. The method for optimizing the impedance of the transmission line and the resistive elements may be based on the impedance of the tap device and the number of taps in the transmission line.

[0052] Various configurations of multitap transmission lines are also provided herein. In at least one embodiment, the multitap transmission line is composed of a planar structure using striplines or microstrip waveguides. A multitap transmission line in a planar structure using striplines or microstrip waveguides can be constructed on a printed circuit board or other planar substrate. Furthermore, embodiments of unibody structures can also be realized using rigid-flex PCB technology.

[0053] In at least one embodiment, the multitap transmission line consists of a backplane arrangement of multiple planar multitap transmission lines. In one example, the multiple multitap transmission lines in the backplane arrangement reuse or use for another purpose PCIe connectors, backplanes, and plug-in cards, as described herein by at least one embodiment.

[0054] In another embodiment, the multi-tap transmission line is composed of a coaxial structure using a coaxial waveguide realized using coaxial standoffs and coaxial structures on a printed circuit board. In some cases, this multi-body configuration can provide an easily reconfigurable structure useful for stacked computers.

[0055] Various use cases of multitap transmission lines are also provided herein. In at least one embodiment, the multitap transmission line is implemented in an automobile. In another embodiment, the multitap transmission line is implemented in a remotely operated vehicle (ROV). In a further embodiment, the multitap transmission line is implemented in a server rack. In yet another embodiment, the multitap transmission line is implemented in a processor chip.

[0056] Multi-tap transmission line (MTL) Here, we refer to Figure 2 to illustrate a high-level block diagram of a multi-tap transmission line 200 according to one embodiment. In the illustrated embodiment, the multi-tap transmission line 200 is terminated at both ends having termination points 402. As shown in the figure, the transmission line 200 is terminated at a first end 402a and a second end 402b. As shown below, the transmission line can branch to a number of termination points and therefore have a number of second ends.

[0057] In the illustrated embodiment, the transmission line has a corresponding characteristic impedance of value Zc. The ends 402a and 402b of the transmission line have a first end impedance and a second end impedance, respectively. In the optimized transmission line 200, the first end impedance and the second end impedance have the same value as the characteristic impedance value Zc of the transmission line. This provides the advantage of reducing or eliminating signal reflection of the signal 405 to the transmission line.

[0058] The transmission line 200 serves as a communication medium between multiple tap devices (TDs) 411, which are connected to the multi-tap transmission line through multiple tap ports (Ts) 403 numbered from 1 to N. The tap circuit, including the tap ports 403 and tap devices 411, is shown in reference number 400. Each tap port 403 is characterized by a tap impedance value of Zo.

[0059] In the various embodiments disclosed herein, the characteristic impedance value Zc is lower than, and in some cases considerably lower than, the individual tap impedance values ​​Zo.

[0060] In an optimized transmission line, the first and second end impedances remain matched to the transmission line when the tap device 411 is connected to the multi-tap transmission line 200. Matching the first and second end impedance values ​​to the transmission line impedance values ​​eliminates wave reflection at the endpoints of the transmission line.

[0061] The tap device 411 may be provided in the form of an RF transmitter output, an RF receiver input, a shared input / output of an RF transceiver, a combined current of one or more RF transceivers, a test port of a vector network analyzer (VNA), a test port of a time-domain reflectivity measurement (TDR) analyzer, a termination point, a tap of another multitap transmission line, and / or any other RF device.

[0062] Figure 3 shows a block diagram of a branched multitap transmission line 300 according to another embodiment of the present disclosure. In this embodiment, power distributors 416(PS) with the same characteristic impedance Zc as the multitap transmission line are used to construct various network topologies. In the embodiment shown in Figure 3, there are two termination points at the second end, such as a first second end 402b and another second end 402c. The configuration of the power distributors may include any number of distributors 416 on the transmission line, such as 2, 3, 4, 5, 6...N (where N is any positive integer).

[0063] In another embodiment, the multitap transmission line may have a plurality of first ends 402a. Similarly, in a further embodiment, the multitap transmission line may be multiple branched, in which case the first transmission line 401a branches into a plurality of transmission lines 401b and 401c, and at least one of the plurality of transmission lines 401b and / or 401c further branches into a plurality of ends.

[0064] Figure 3 shows a 3-port power distributor 416, but it will be understood that any number of N-port power distributors can be used to enable N branching of the transmission line. In any such embodiment of the transmission line, the performance will be limited by the normal power loss at each distributor.

[0065] In some cases, multi-tap transmission lines can be mounted as rigid printed circuit boards. In other cases, multi-tap transmission lines can be mounted as individual flexible printed circuit boards. Multi-tap transmission lines can also be mounted as flexible printed circuit boards with adhesive tape.

[0066] Similarly, multi-tap transmission lines can be implemented as branch configurations, for example, as shown in Figures 3 and 55. Figure 3 shows an embodiment of a branch configuration with a 3-port power distributor in the center. Figure 55 shows an embodiment of a branch configuration with a 4-port power distributor.

[0067] In one embodiment, the transmission line is shielded, and the "hot" signal line for transmission is sandwiched between two ground planes. This shielded configuration may be equivalent to the stripline configuration described herein.

[0068] To make it clearer, a stripline embodiment refers to a shielded transmission line sandwiched between two ground / shield layers. A microstrip embodiment refers to an unshielded line where the transmission line is above the ground layer, with the top exposed and having a substrate configuration. In one embodiment, the entire substrate can be shielded with some care to shield the MTL at the "outside" level.

[0069] Here, we refer to Figure 4, which shows a schematic diagram of an example tap circuit 400. As shown in the figure, the tap circuit 400 includes a left port (L) 430a and a right port (R) 430b. The left port 430a is connected to a first transmission line 401a. The first transmission line 401a is connected to a first resistive element (Rs) 435a, which is connected to a second resistive element (Rs) 435b. The second resistive element 435b is connected to a second transmission line 401b, which is connected to the right port 430b. A tap resistive element (Rt) 436 is connected to the common point between the first resistive element 435a and the second resistive element 435b. These three resistive elements are connected in a T-shape as shown in the figure. The first and second resistive elements are also referred to as series resistive elements in this specification.

[0070] In the illustrated embodiment, each transmission line 401a, 401b has a characteristic impedance Zc. The first resistive element 435a and the second resistive element 435b each have the same resistance value or substantially the same resistance value Rs. The tapped resistive element 436 has a resistance value Rt. The tapped resistive element 436 is connected to the tapped port 403.

[0071] Figure 5 provides a schematic diagram showing an embodiment of the multi-tap transmission line 500. The transmission line 500 has a resistive element (R) with resistance value Zc. L The transmission line 500 has a first end 502a, indicated as the left port L terminated at 534. R It also has a second end 502b, indicated as the right port R terminated at 536. N connected tap circuits 400, such as the one shown in Figure 4, are also shown. As shown in the figure, each tap circuit 400 is connected to its respective external tap device 511 through its respective tap port 503. Tap port 503 is similar to tap port 403 in Figure 4. Left port (L) 530a is similar to left port 430a in Figure 4, and right port (R) 530b is similar to right port (R) in Figure 4.

[0072] As shown in Figure 5, the tap device 511 is connected to the multitap transmission line 500 at the corresponding tap port via the corresponding tap line 504. In one embodiment, if one of the tap devices 511 is disconnected, interrupted, short-circuited, or damaged, or otherwise lost connection to the multitap transmission line, the multitap transmission line will still operate with the remaining tap devices 511. Similarly, in some other embodiments, if the tap line 504 is disconnected, interrupted, short-circuited, or damaged, the multitap transmission line will continue to operate with the remaining tap devices 511 and the tap line 504.

[0073] Optimization method A method for optimizing a multitap transmission line is provided herein. In at least one embodiment, a method for optimizing a multitap transmission line, such as the multitap transmission line of Figures 4 and 5, is used to determine the characteristic impedance Zc of the multitap transmission line and the resistance values ​​of various resistive elements of the tap circuit 400. In such an embodiment, the method for optimizing the impedance and resistive elements of the transmission line is based on the impedance value (Zo) of the tap device 511 and the number N of tap ports connected to the multitap transmission line.

[0074] In at least one embodiment, a method for optimizing a multitap transmission line includes the step of determining a tap impedance value (Zo) associated with each tap device, such as tap device 511. In one embodiment, the tap impedance value (Zo) is a predetermined data value. Input data can be obtained from the tap device manufacturer or system designer and may be selected to optimize system performance. In various embodiments, the tap impedance value Zo is typically around 50 ohms.

[0075] The method further includes the step of determining the total number of tap ports connected to the transmission line. Next, the method includes the step of determining the optimal characteristic impedance value (Zc) of the multi-tap transmission line. The step of determining the optimal characteristic impedance value includes determining the characteristic impedance value Zc that minimizes the insertion loss between the first and last tap devices. As described below, the Zc value is typically lower, and in some cases considerably lower, than the tap impedance value Zo.

[0076] Furthermore, the method includes the step of determining the series resistance (Rs) and tap resistance (Rt) of various resistive elements in the tap port, such as the tap circuit 400 in Figure 4, based on the determined optimal characteristic impedance value (Zc). The characteristic impedance value (Zc) is determined such that the loss between the first tap circuit and the last tap circuit connected to the transmission line is minimized.

[0077] In some embodiments, the step of determining the optimal characteristic impedance value (Zc) includes selecting a candidate impedance value (Zc'), which is selected from a range of values ​​between 0 and the end impedance value. This end impedance value is less than the tap impedance value (Zo) associated with the tap device. The method further includes, for each candidate impedance value, determining the worst-case insertion loss between the first tap circuit and the last tap circuit based on the candidate impedance value (Zc') and the tap impedance value (Zo) corresponding to the tap port. In some cases, the worst-case insertion loss is determined based on the determination of the longitudinal and transverse insertion losses by the following formulas. The optimal characteristic impedance value (Zc) is based on the candidate impedance value (Zc') that minimizes the worst-case insertion loss.

[0078]

number

[0079] TTLN represents the worst-case insertion loss between the first tap circuit (1) and the last tap circuit (N).

[0080] In equation (1), LIL is given by the following equation:

[0081]

number

[0082] This represents the longitudinal insertion loss value determined according to the formula, where j is a range of values ​​indicating the tap index, ranging from 2 to (N-1), N is the total number of tap ports, and PR and PT represent the maximum output conditions at the left and right ports, such as 502a and 502b, respectively.

[0083] In equation (1), TIL is:

[0084]

number

[0085] This is the lateral insertion loss value determined according to the formula, where PT and PR represent the maximum output conditions at the tap port and right port, respectively, such as 503 and 502b.

[0086] In at least one embodiment, the series resistance value (Rs) corresponding to the first and second resistor taps in the tap circuit, such as resistor elements 435a and 435b, is given by the following formula:

[0087]

number

[0088] It is determined according to the formula, where Zo(j) is the tap impedance value of tap port j, j is a range of values ​​indicating the tap index ranging from 1 to N, N represents the total number of tap ports, and Zc is the optimal characteristic impedance value.

[0089] In at least one embodiment, the tap resistance (Rt) of a third resistive element, such as the tap resistive element 436 in Figure 4, is given by the following formula:

[0090]

number

[0091] It is determined according to the formula, where Zo(j) is the tap impedance value of tap port j, j is a range of values ​​indicating the tap index ranging from 1 to N, N represents the total number of tap ports, and Zc is the optimal characteristic impedance value.

[0092] As previously stated, equations (4) and (5) are derived from the maximum output transfer conditions of the left port L, the right port R, and the tapped port T.

[0093] In at least one embodiment, the alternative characteristic impedance value (Zc) is selected from a range of -30% to +30% of the optimal characteristic impedance value. In other cases, the alternative characteristic impedance value (Zc) is selected from a range of approximately -30% to approximately +30% of the optimal characteristic impedance value. Depending on the use case in which the multitap transmission line optimized according to the method herein is used, the characteristic impedance value selected for use may range from approximately -35% to +35%, -40% to +40%, or other ranges around the optimal characteristic impedance value.

[0094] In at least one embodiment, the optimal characteristic impedance value (Zc) is determined by graph analysis, for example, by plotting the loss function according to equation (1) as a function of candidate impedance values. The optimal characteristic impedance value is based on the candidate impedance value corresponding to the minimum value of the loss function in equation (1).

[0095] In this embodiment, the first step of the method includes determining the series resistance (Rs) and tap resistance (Rt) of a tap circuit, such as circuit 400 in Figure 5, as functions of Zc and Zo under maximum power transmission conditions for all ports. Referring to Figure 5, each of the end ports 502a and 502b is terminated to Zc, port T is terminated to Zo, and for simplification, the length of the transmission line ML is zero. In this embodiment, the series resistance (Rs) is determined according to equation (6), which is a simplified version of equation (4), and the tap resistance (Rs) is determined according to equation (7), which is a simplified version of equation (5).

[0096]

number

[0097]

number

[0098] Next, refer to Figure 6 to show the graphical analysis and determination of the optimal tap resistance (Rt) and series resistance (Rs) based on the characteristic impedance (Zc) of a multi-tap transmission line. Figure 6 shows plot 600, which shows the tap resistance (Rt) 602 and series resistance (Rs) 606 as functions of the characteristic impedance (Zc) 604. In this embodiment, the first step includes, as an example, calculating the values ​​of Rt and Rs using equations (6) and (7). In this embodiment, since the impedance value used in most RF transceivers is 50 ohms, a tap impedance of Zo = 50 ohms was used, but any appropriate tap impedance value Zo may be used. Next, the resulting equations for Rs and Rt were plotted as functions of the characteristic impedance Zc, as shown in plot 600.

[0099] In the second step of the method described above, the longitudinal insertion loss (LIL) between the first terminal port 502a (L port) and the last terminal port 502b (R port) is determined using equation (8) under the same number of tap circuits and conditions. The lateral insertion loss TIL between the tap port 503 (T port) and the last terminal port 502b (R port) can be determined as a function of impedances Zc and Zo using equation (9). Equations (8) and (9) are simplified versions of equations (2) and (3), respectively. Any appropriate tap impedance value Zo may be used, such as 25 ohms, 50 ohms, or 75 ohms, but is not limited to the following.

[0100]

number

[0101]

number

[0102] In the formula, PL, PR, and PT are the outputs of the L port, R port, and T port, respectively.

[0103] The functions LIL and TIL can be analyzed graphically by plotting the functions, as shown in Figure 7. Figure 7 shows the first plot 702 and the second plot 706, respectively, representing TIL and LIL as functions of the characteristic impedance value (Zc) 704 with respect to the tap impedance value (Zo) of 50 ohms.

[0104] In the third step of determining the optimized characteristic impedance, LIL and TIL can be applied to the multi-tap transmission diagram in Figure 5 to determine the insertion loss between two tap ports, as shown in equation (10).

[0105]

number

[0106] In some cases, k is a positive integer greater than 2, representing the number of taps between the ports under test.

[0107] In a subsequent step, equation (11) can be used to determine the worst-case insertion loss between port T1 and port TN for the N-tapped multitap transmission line in Figure 5. Equation (11) is a special case of equation (1) where all taps have a Zo impedance.

[0108]

number

[0109] Figure 8 is a graph 800 showing the dependence of the worst-case insertion loss (TTLN) 802 based on the characteristic impedance (Zc) 804 of a multi-tap transmission line on multiple N values ​​ranging from 4 taps to 64 taps, where N is the number of taps in the transmission line.

[0110] Figure 9 is a graph 900 showing the dependence of the worst-case insertion loss (TTLN) 902 based on the characteristic impedance (Zc) 904 of a multi-tap transmission line on multiple N values ​​ranging from 4 taps to 512 taps, where N is the number of taps in the transmission line.

[0111] In the plots of Figures 8 and 9, the TTLN is calculated for various N values ​​according to Zc. As an example, a Zo value of 50 ohms is used, but any tap impedance value can be used. Plots 800 and 900 are analyzed to determine the lowest insertion loss for each TTLN plot. For example, this can be done using a graph by marking the lowest loss point with x, as shown in the plots of Figures 8 and 9. If necessary, the lowest insertion loss for each TTLN plot can be determined using any appropriate method to find the overall maximum or minimum value or the location of the local maximum or minimum. While the graphs of Figures 8 and 9 are based on equation (11) where all taps have the same tap impedance value (Zo), it will be understood that the graphs of Figures 8 and 9 can be created for other situations where various taps have different respective impedance values ​​(Zo).

[0112] Several methods can be used to find the global or local extrema of a function. A first method may involve a derivative test, which involves setting the function's derivative to zero and then using a second derivative test to determine whether each critical point corresponds to a local minimum, local maximum, or neither. Another method is graph analysis, which involves plotting the function to visually understand the location of the extrema. Yet another method is optimization techniques, such as the Lagrange multiplier method, which can maximize or minimize a specific quantity.

[0113] As shown in Figures 8 and 9, for N=8, the insertion loss penalty resulting from using a typical 50-ohm characteristic impedance instead of the optimal impedance value (Zc) can be determined to be approximately 15 dB as the insertion loss difference between points 810 and 808 in Figure 8. To be more certain, if a 50-ohm characteristic impedance value (Zc) is used instead of the optimal Zc value of 14 ohms (where 50 ohms is a typical tap impedance value), then the insertion loss penalty is an additional attenuation determined by TTLN(at point 810) - TTLN(at point 808) = 47 dB - 31 dB (approximately) = 15 dB (approximately).

[0114] The optimal characteristic impedance (Zc) is determined by identifying the point where the insertion loss is minimum or maximum or minimum overall. In this example, the minimum loss is determined to occur when the characteristic impedance Zc is approximately 14 ohms, as shown at point 808 in Figure 8. Therefore, the optimal characteristic impedance Zc is determined to be approximately 14 ohms in the example of an 8-tap device. It should be noted that an alternative characteristic impedance value (Zc) may be selected from a range such as -30% to +30% of the optimal characteristic impedance value. A multi-tap transmission line with multiple devices can also be created using an alternative characteristic impedance value. However, the insertion loss will likely be greater than when the optimal characteristic impedance value Zc is selected.

[0115] In another example, in the special case of N=24 taps and Zo=50 ohms, the optimal impedance Zc can be determined to be approximately 4.3 ohms based on the analysis or by the methods described, such as from the plot in Figure 9. With Zc=4.3 ohms, the optimal resistance Rs can be determined to be approximately 0.094 ohms, and the tap resistance Rt can be determined to be approximately 47.8 ohms from the plot in Figure 6 or using equations 4 and 5, or 6 and 7. Therefore, the optimal solution for {Zc, Rs, Rt} for a multi-tap transmission line with 24 taps, each with a tap impedance of Zo=50 ohms, can be determined to be {4.3 ohms, 0.094 ohms, 47.8 ohms}.

[0116] Table 1 below shows an example of the optimal solution for {Zc, Rs, Rt} for a multi-tap transmission line with N taps where the tap impedance value Zo ranges between 25 ohms, 50 ohms, and 75 ohms.

[0117] [Table 1]

[0118] Since multi-tap transmission lines with multiple devices can be created using alternative resistance values ​​for Rs and Rt, it should be noted that these alternative resistance values ​​can also be selected from a range of -30% to +30% of the optimal resistance value.

[0119] While it may be more convenient to operate all tap devices with the same tap impedance (Zo), the multi-tap transmission lines disclosed herein can be operated with different tap port impedances (Zo). In such cases, the resistive elements (Rs, Rt) of each tap circuit are calculated for a specific tap impedance (Zo) based on the formula described above. In such cases, a common characteristic impedance (Zc) is used for the entire multi-tap transmission line.

[0120] In some embodiments, the multi-tap transmission line model can be further improved by considering the actual delay and loss of the ML transmission line for each tap circuit. For example, in such embodiments, the multi-tap transmission line disclosed herein, such as the transmission line in Figure 4 or Figure 5, can be configured as a stripline having a relative permittivity (DK) of 3.74, dielectric loss coefficient (DF) of various values, and a line width of 3.6 mm between two ground layers to obtain a characteristic impedance of 4.3 ohms, while the length of the ML is selected to be 9 mm each to make the total tap pitch 18 mm. The number of taps in this multi-tap transmission line model is set to N=24. The configuration and shape of this transmission line can also be optimized with respect to the number of taps.

[0121] To illustrate how actual delay and loss are determined, four case studies were analyzed as examples. The four cases are shown below, but are not limited to these: (A) very low loss: DF=0.001 and Rs=0.094 ohms, (B) very low loss: DF=0.001 and Rs=0, (C) low loss: DF=0.01 and Rs=0, and (D) high loss: DF=0.02 and Rs=0.

[0122] Figure 10 is a graph 1000 showing the frequency dependence of insertion losses S1-24 between taps T1 and T24 for multi-tap transmission lines previously described for examples (A), (B), (C), and (D). Plot A is shown using reference number 1014. Plot B is shown using reference number 1012. Plot C is shown using reference number 1016, and plot D is shown using reference number 1018. Plots A-D show insertion losses 1002 under different circumstances as a function of frequency 1004.

[0123] As can be seen from Graph 1000, plot A 1014 for insertion loss is consistent with the value previously calculated for TTLN from equations (8) to (11) or from the graph in Figure 9. A comparison point can be taken at a very low frequency so that A in this plot shows a slight downward slope due to the non-zero dissipation coefficient. Plots 1012(B), 1016(C), and 1018(D) each show peaks 1011, 1015, and 1017, respectively, at approximately 4.3 GHz, resulting from wave reflections in a repeating structure formed by equally spaced taps of 18 mm, due to the Rs=0 deviation from the theoretical Rs=0.094 ohms. Since there are no reflections, plot A 1014, as expected, has no peak. Plot B 1012 shows the lowest insertion loss as expected, but the difference between plot B 1012 and plot A 1014 provides a measure of the insertion loss penalty caused by the series resistor Rs. Plot D 1018 shows the highest predicted insertion loss, pointing to the highest dielectric loss and limitations on the overall performance of the multi-tap transmission line. Plot C 1016 shows an acceptable compromise between the insertion loss of a good quality FR4 class printed circuit board (PCB) and removing the series resistor Rs from the tapped circuit. This is because plots C 1016 and A 1014 intersect near the middle of the target frequency range (approximately 3.5 GHz). Therefore, it may be advantageous to emulate the effect of the series resistor Rs using the intrinsic PCB insertion loss resulting from the combination of dielectric and electrical losses.

[0124] Figure 11 is a plot 1100 showing the frequency dependence of the return loss SL-L for the four cases (A), (B), (C), and (D) described above. This return loss is a measure of standing waves along the multitap transmission line and serves as a comparative measure of immunity to radiated interference and external interference among the four cases. Plot A is shown using reference number 1114. Plot B is shown using reference number 1112. Plot C is shown using reference number 1116, and plot D is shown using reference number 1118. Plots A-D show the return loss 1102 under different circumstances as a function of frequency 1104.

[0125] Plots B 1112, C 1116, and D 1118 show higher deflections at approximately 4.3 GHz due to wave reflections in a repeating structure formed by equally spaced taps of 18 mm, for a deviation of Rs = 0 from the theoretical Rs = 0.094 ohms. Plot A 1114 shows a much smaller deflection, which will decrease further as Rs and Rt are identified with greater precision. The deflection at 4.3 GHz can be reduced by decreasing the number of taps or by dispersing the length of the ML line and using different values, thus reducing the cumulative effect on the overall quality (Q) coefficient for the entire multi-tap transmission line.

[0126] The fluctuation at 4.3 GHz shifts in frequency when the tap structure pitch changes from the current value of 18 mm, and increases in frequency when the pitch decreases. The fluctuation at 4.3 GHz repeats with a periodicity of 4.3 GHz across the entire spectrum, with the next fluctuation observed at 8.6 GHz, but not shown in the plot. A small ripple consisting of about six peaks over a frequency span of 1 GHz is observed in all plots with varying amplitudes and is generated by wave reflections over the entire length of the multi-tap transmission line, 24 × 18 mm. This ripple is, as expected, highest in plot B 1112 due to the worst matching. The minimum value of this ripple observed in plot D 1118 is a result of high insertion loss gradually reducing the amplitude of the reflected wave. In other words, high insertion loss in multi-tap transmission lines may have some advantage in minimizing reflections.

[0127] Planar multi-tap transmission cable (PTML) Figures 12 to 20 show a planar multitap transmission line (PMTL) according to one embodiment.

[0128] As shown in Figures 12-13, the PMTL consists of a front panel 222 having multiple mounting holes 221. Multiple tap connectors 223 are attached to the front panel using multiple nuts 225. As shown in detail in Figures 15-20, the PMTL comprises ground planes 237 and 238, via structures 239A, 239B, 239C, a tap pin pad 233 surrounded by a tap connector center pin 230B3 of the tap connector 223, a gap 230B2, a transmission stripline 232, a termination resistor element 230D3, a ground termination pad 230D1, a termination microvia set 230D2, a pad 230D1, a tap resistor element 230E1, a tap stripline 230E3, a tap pad 230E2, and a tap microvia set 230E4.

[0129] The PMTL of this embodiment can be used in a server rack environment. In such a use case, the tap connector 223 connects the PMTL to the Wi-Fi connector of a server in the rack via a coaxial cable.

[0130] Refer to Figure 14, which shows a laminated structure 210 used to manufacture a printed circuit board. The laminated structure 210 shows a first copper layer (L1) 1402, a first core layer (C) 1410, a second copper layer (L2) 1404, an insulating layer (PP) 1412, a third copper layer (L3) 1406, a second core layer (C) 1414, and a fourth copper layer (L4) 1408. Through-hole via type (V1-4) 1420 is included between layer (L1) 1402 and layer (L4) 1408, and micro-via via type (V1-2) 1422 is included between layer (L1) 1402 and layer (L2) 1404.

[0131] In one example, the first copper layer 1402 has a thickness of 35 μm, and the core laminate 1410 is made from FR408HR material with a thickness of approximately 0.089 mm, a dielectric constant (DK) of approximately 3.74, and a dissipation coefficient (DF) of approximately 0.009. The core laminate 1410 may be manufactured by Isola Group or another similar supplier. The second copper layer 1404 has a thickness of approximately 18 μm and has an embedded resistive thin film layer with a sheet resistance of 25 ohms / □, such as those manufactured by Qantic Ticer, Quantic Ohmega, or another supplier. The insulating layer 1412 consists of a prepreg (PP) and core laminate, its thickness adjusted for a total PCB thickness of 1.6 mm, and is made from the same FR408HR material used for the core 1410. The third copper layer 1406 is an empty (etched-off) copper layer. The empty copper layer 1406 maintains the lamination symmetry necessary for manufacturing convenience. The second core layer 1414 can have the same configuration as the first core layer 1410. Next, the fourth copper layer (L4) 1408 can have the same thickness as layer 1402.

[0132] It will be recognized that various modifications may be made in the manufacturing process of PCBs based on the laminated structure 210, depending on local process capabilities and material availability. Such modifications should be adjusted in accordance with the PMTL shape and parameters described herein. However, non-essential PCB layers used in PCB manufacturing, such as plating, solder masks, or silkscreens, which are not shown here, can be completed according to commonly used methods.

[0133] Herein, we refer to Figures 15-20, which provide various embodiments of taps in a planar multitap transmission line. Figure 15 provides a rear perspective view of tap 1500 of a planar multitap transmission line. Figure 16 provides a front perspective view of features 1600 and via structures on the outer layer of the tap in Figure 15. Figure 17 provides an enlarged view 1700 of detail 230B in Figure 15. Figure 18 provides an enlarged view 1800 of the active conductive features of the tap in Figure 15. Figure 19 provides an enlarged view 1900 of detail 230D in Figure 18. Figure 20 provides an enlarged view 2000 of the detail identified as 230E in Figure 18.

[0134] In at least one embodiment, the transmission stripline 232 is located on a second copper layer L2 1404 and is fabricated with a matching impedance of Zc = 4.3 ohms to a ground plane 238 on a first copper layer L1 1402 and a ground plane 237 on a fourth copper layer L4 1408, and has a nominal width of 3.6 mm. In such an embodiment, the terminating resistor element 230D3 can be constructed in a similar manner at both the left and right ends of the entire transmission stripline 232 and can be fabricated by sequential etching on a 25 ohm / □ thin film resistor layer embedded in the second copper layer L2 1404, and has the same width as the transmission stripline 232 and a length of 0.62 mm to have a final resistance of 4.3 ohms.

[0135] The termination pad 230D1 is constructed on a second copper layer L2 1404 having the same width as the transmission stripline 232 and the termination resistor element 230D3, and connects the latter to the ground plane 238 on the first copper layer L1 1402 via a low-impedance path of the termination microvia set 230D2.

[0136] Via structures 239A and 239B utilize type V1-4 1420 vias, which consist of a hole diameter of approximately 0.16 mm, a pad of 0.55 mm, and a via spacing of approximately 1 mm. These vias connect the ground plane 238 on the fourth copper layer L4 1408 and the ground plane 237 on the first copper layer L1 1402, forming a shield cage around the transmission line.

[0137] The microvias used in the terminating microvia set 230D2 and the tapping microvia set 230E4 are of type V1-2 1422, with a hole diameter of approximately 0.1 mm, a landing pad diameter of 0.35 mm on the first copper layer L1 1402, and a landing pad diameter of 0.325 mm on the second copper layer L2 1404.

[0138] The tap resistor element 230E1 is fabricated by sequential etching on a 25 ohm / □ thin film resistor embedded in the second copper layer L2 1404, and has a finished length of 0.733 mm and a width of 0.383 mm to achieve a final resistance of 47.8 ohms.

[0139] The tap strip line 230E3 is fabricated as a 50-ohm matching impedance on the second copper layer L2 1404 to match the impedance of the tap connector 223, and has a nominal width of 0.125 mm and an approximate length of 1.6 mm. There may be advantages to reducing the length of the tap strip line as much as possible.

[0140] The tap pad 230E2 has a width of approximately 0.35 mm and a length of approximately 0.8 mm, and is compatible with the tap micro via set 230E4.

[0141] The tap resistor element 230E1 is connected as close as possible to the transmission stripline 232, and at the other end to the tap stripline 230E3, which is further connected to the tap pad 230E2, which is further connected to the tap pin pad 233 via the tap microvia set 230E4.

[0142] The gap 230B2 has an optimal opening of 0.5 mm around the tap pin pad 233. The tap connector center pin 230B2 surrounded by the four ground pins of the same connector, the tap pin pad 233, the gap 230B2, the tap microvia set 230E4, the tap pad 230E2, the ground plane 238 on the first copper layer L1 1402, the ground plane 237 on the fourth copper layer L4 1408, and the via structure 239C connecting these ground planes 238 and 237 and positioned to straddle the tap strip line 230E3 on the second copper layer L2 1404 form a critical transition from the coaxial waveguide to the tap strip line 230E3 of the tap connector 223.

[0143] Other taps in the PMTL have the same structure as described, and the transmission stripline 232 is a continuous line of the same width over the entire length of the PMTL. It should be noted that alternative geometric values ​​can also produce multi-tapp transmission lines with multiple devices, and therefore, a range of appropriate geometric shapes can be selected. This range may be any appropriate range, for example, -30% to +30%, -35% to +35%, etc.

[0144] PMTL modeling and simulation Figure 21 shows a connection diagram of a planar tap PT2100 modeled according to the diagrams and related descriptions in Figures 15-20, except for the termination resistor element 230D3, termination pad 230D1, and termination microvia set 230D2. This model is symmetrical with respect to the centerline of the tap connector over the 18 mm tap length and is expandable to construct a circuit model for the entire PMTL in Figure 13 by simply connecting 24 planar tap PT models from Figure 21, as shown in Figure 23. Tap port 2115 is similar to tap port 403 in Figure 4. Left port (L) 2105 is similar to left port 430a in Figure 4, and right port (R) 2110 is similar to right port (R) 430b in Figure 4.

[0145] Next, refer to Figure 22. This figure shows the S-parameters extracted and plotted for a planar tap PT model such as the PT2100 in Figure 21. The S-parameters can be extracted using any 3D EM software. Graph 2200 shows the attenuation on the y-axis 2202 as a function of frequency on the x-axis 2204.

[0146] As shown in the figure, Graph 2200 shows the first plot SL-R2220, which represents the insertion loss between the left port L2105 and the right port R2110, equivalent to the vertical insertion loss LIL defined by equation (8) and plotted in Figure 7. Plot ST-R2205 represents the insertion loss between the left port L2105 and the right port R2110, equivalent to the horizontal insertion loss TIL defined by equation (9) and shown in Figure 7. Plot ST-T2210 is the return loss at tap port T2115, and plot SL-L2215 represents the return loss at the left port L2105.

[0147] As shown in Figure 22, plot SL-R2220 is low, as expected for a tap port well isolated by an 18mm line and an internal resistive element Rt with extremely low parasitic components. This slope is mainly caused by dielectric loss and copper loss. Plot ST-R2205 is close to the predicted TIL of approximately -17dB at Zc=4.3 ohms, as seen in Figure 7. Plot SL-L2215 has attenuation of less than -30dB, indicating almost no reflection along tap 2115. Plot ST-T2210 shows very low attenuation in the low frequency range, but its performance degrades somewhat in the high frequency range. This degradation may be caused by the transition from the tap connector to the transmission stripline.

[0148] The S-parameters predicted for the taps modeled in Figure 21 can be connected to circuit 2300 as shown in Figure 23, and the behavior of the entire PMTL in Figure 13 can be modeled using an appropriate circuit simulator.

[0149] The tap circuit 2350 shown in Figure 23 is similar to the tap circuit 400 in Figure 5. As shown in Figure 23, there are 24 tap ports 2350, numbered T1 through T24.

[0150] The circuit modeled in Figure 23 was tested in two states, plotted in Figure 24: (1) terminated state: all tap ports T terminated to a nominal impedance of 50 ohms, and (2) open state: all untested tap ports T left open.

[0151] The ports under test are always terminated. While the terminated state is considered normal, the open state measures the impact on performance loss that occurs in PMTLs operating with unconnected or faulty taps open. Short-circuit tap states were determined to result in a similar level of penalty as open states, which have been intentionally omitted for a clearer explanation.

[0152] Figure 24 provides plot 2400 for modeling insertion loss 2402 as a function of frequency 2404. Plots (So1-24)2410 and (St1-24)2405 represent the insertion loss between tap ports at each end of the PMTL in the open and terminated states, respectively. Referring to Figure 23, the tap ports at each end are the first tap port (T1) and the last tap port (T24).

[0153] Plots (So12-13)2425 and (St12-13)2430 represent the insertion loss between adjacent tap ports at the center of the PMTL in the open and terminated states, respectively. Referring to Figure 23, the adjacent tap ports at the center of the PMTL are the 12th tap port (T12) and the 13th tap port (T13).

[0154] Plots (So12-12)2415 and (St12-12)2420 represent the return loss of the tap port at the center of the PMTL in the open and terminated states, respectively. Referring to Figure 23, the tap port at the center of the PMTL is the 12th tap port (T12).

[0155] Plots (SoLL)2440 and (StLL)2445 represent the return loss at the left port of the PMTL in the open and terminated states, respectively.

[0156] The taps in the center of the PMTL were selected to evaluate plots (So12-12)2415 and (So12-13)2425 regarding the worst-case scenario location. This is because reflection decreases as the tap approaches the end of the PMTL, and the effect of tap discontinuities between that tap and the end gradually diminishes.

[0157] As can be seen in Figure 24, plot (St1-24)2405 is similar to plot (S1-24) for case (C)1016 in Figure 10, which demonstrates the modeling. Plot (So1-24)2410 follows plot (ST1-24)2405, but with superimposed fluctuations resulting from the cumulative effect of disturbances in the open tap, although the amplitude is small and there is little to no concern about PMTL operation. Plots (So12-13)2425 and (St12-13)2430 are close to the values ​​predicted by equation (8) to (10) or Figure 7, showing little to no difference between the open and terminated states and good isolation from other taps. Plots (So12-12)2415 and (St12-12)2420 are nearly identical, indicating good isolation of the return loss from other taps in that tap. The small peak at approximately 4.3 GHz appearing in plots (So12-13)2425 and (St12-13)2430 is due to the reflection of waves propagating along the multi-tap transmission line by a periodic structure created by the 18 mm pitch between taps. Each tap creates a discontinuity due to the reduction of the resistance of the resistive element Rs to zero and its operation as a lossy transmission line. The reflections along the multi-tap transmission line quantified in plots (SoLL)2440 and (StLL)2425 are consistent with the plots in Figure 11 of the preliminary model for the same reasons as described above.

[0158] PMTL design instructions In at least one embodiment, the PMTL parameters are selected as follows: First, the optimal characteristic impedance (Zc) value for the desired number of taps is selected from Figure 8 or Figure 9, etc. Next, a test specimen is created from a laminate best suited to the desired PMTL configuration, such as a stripline or microstrip transmission line. The insertion loss with respect to frequency at the desired PMTL length is measured. This test can be performed at low cost and can predict the worst-case insertion loss more accurately than using material data sheets or other engineering approximations. Next, the insertion loss plot obtained in the previous step is shifted downward by the worst-case insertion loss (TTLN) value corresponding to the intended number of taps, read from Figure 8 or Figure 9. This new plot provides a useful approximation of the maximum inter-tap insertion loss over the intended frequency range.

[0159] Next, the tap resistor value is determined based on equation (5). In some cases, the tap resistor is implemented in an integrated resistive layer to minimize the parasitic components of the tap. Then, the lowest possible characteristic impedance value (Zc) is utilized. This provides the benefits of reducing PMTL radiated interference and improving resistance to external interference and tap load defects. The lowest possible characteristic impedance value (Zc) is determined based on the RF link budget or the allowable space on the PCB. Further reduction of the characteristic impedance value (Zc) can increase insertion loss and transmission line width.

[0160] Next, the series resistance element (Rs) is calculated based on equation (4). A series resistance element using the same thin-film technology as the tap resistance element (Rt) is used to reduce reflections along the transmission line as needed. Furthermore, the series resistance element value (Rs) is adjusted to optimize insertion loss and reflection performance. In addition, the shape and thin-film material used for the series resistance element (Rs) and tap resistance element (Rt) are adjusted to reduce geometric discontinuities along the PMTL line, thereby minimizing parasitic effects on the PMTL. This is done while keeping the common node area to a minimum, as the insertion of the series resistance element (Rs) may increase reflections rather than prevent them.

[0161] The frequency response of PMTLs mounted on the same layer without any transition zones or connectors is substantially flat over a frequency range up to 100 GHz, and in this range, the insertion loss of the PCB causes the expected damage.

[0162] Backplane planar multitap transmission line (bPMTL) Figure 25 is a schematic diagram of a backplane PMTL or bPMTL2500 according to one embodiment. The backplane PMTL2500 comprises a backplane 241, a plurality of appropriately terminated PMTL2505s, a plurality of tap resistor elements Rt2510s, and a plurality of slot connectors 242s. Each slot connector 242 comprises a plurality of differential connector pin pairs 243s. The plurality of PMTL2505s are arranged in parallel, with each tap resistor element Rt connected to the p pin 2515 of the differential pin pair 243 by the shortest transmission line, and the n pin 2520 of the differential pin pair 243 being grounded. The differential pin pairs 243s are arranged as a group as part of the slot connector 242s. Each slot can be fitted with a plug-in card having mating pins and RF tap devices connected to the corresponding tap port of the bPMTL via the p pin 2515 of the corresponding differential pin pair 243. The grounded n-pin 2520 controls the impedance of the differential pin pair 243, achieving an effective impedance of approximately 50 ohms for the transmission line connected to p-pin 2515.

[0163] The connection performance between the tap device on the plug-in card and the tap resistor on the backplane is substantially limited by the backplane connector. The impedance of this connection as a transmission line is selected to match the connector impedance and provide a matching pad between the tap device and the connector on the plug-in card. The impedance of the short line between the connector on the backplane and the tap resistor element (Rt) is selected to match the connector impedance, and the resistance value of the tap resistor element (Rt) is calculated using the impedance of the backplane connector as Zo in equation (5).

[0164] Next, a bPMTL optimized for specific end-product requirements can be constructed using the calculated optimal values.

[0165] Coaxial Multi-Tap Transmission Line (CMTL) Next, we will discuss coaxial multitap transmission lines (CMTLs). An incomplete portion or segment of a CMTL is referred to herein as a "coaxial stack," while a CMTL refers to the exact and fully defined coaxial multitap transmission line.

[0166] Figures 26 and 27 show embodiments referred to as coaxial multitap transmission lines 2600, 2700, or CMTL. The CMTL comprises a coaxial cable 301 and a tap device card 310 including a plurality of spring pins 302, mounting bolts 303, coaxial taps 320, coaxial terminations 330, coaxial standoffs 340, coaxial connector adapters 350, and tap devices 311.

[0167] Illustration 2600 in Figure 26 shows how to assemble a CMTL from various parts adapted in size and configuration to meet specific needs.

[0168] Coaxial standoff for CMTL Figures 28 and 29 show parts of the CMTL 2800, 2900, with mounting bolts 303, coaxial termination 330, coaxial standoff 340, coaxial tap 320, and inner standoff 342 surrounded by dielectric standoff 343 surrounded by outer standoff 344.

[0169] The inner standoff 342 holds adjacent cards, such as the coaxial tap 320, tap device card 310, or coaxial termination 330, by clamping them together to the dielectric standoff 343 and outer standoff 344. The required clamping force can be achieved by using a screw-and-nut threaded structure where friction between the screws helps hold them together, or by using a snap-fit ​​type ball-socket joint where friction between the mating ball and its socket structure holds them together. In examples where threaded standoffs are used, means are provided to secure them in place to prevent them from falling out. When ball-socket standoffs are used, means are provided to separate them.

[0170] The inner standoff 342 shown and referenced in Figures 28, 29, 43, and 44 is shown as a modified hexagonal threaded shape to facilitate tightening with a hex socket tool. The inner standoff 342 functions as the inner conductor of the coaxial standoff 340 and conducts coaxial RF current primarily on its surface due to the skin effect. If the inner standoff 342 is part of the coaxial standoff 340, it operates under mechanical tensile stress and requires a flexible conductive gasket attached to one or both of its seating surfaces to ensure proper contact between them and the PCB landing pad. This flexible conductive gasket can be implemented as a gasket field-molded on the seating surface of the inner standoff 342 or as a gasket field-molded on the PCB landing pad to which it is attached.

[0171] In one embodiment, the dielectric standoff 343 is manufactured from a material having a dielectric constant that matches that used for the PCB dielectric material in the coaxial tap 320 or tap device card 310.

[0172] If the outer standoff 344 is part of the coaxial standoff 340, it operates under mechanical compressive stress between adjacent cards such as the coaxial termination 330, coaxial tap 320, and tap device card 310.

[0173] The compressive stress on the outer standoff 344 is substantially equal to the tensile stress on the inner standoff 342. This is because the dielectric standoff 342 is made of a much softer material and therefore typically experiences little stress. The tensile stress in the inner standoff 342 is transferred to the compressive stress in the outer standoff 344, while shear and bending stresses are experienced in the PCB region between them. The outer standoff 344, the inner standoff 342, and the PCB region between them must maintain the structural integrity of the CMTL and distribute stresses from connected large structures such as the coaxial cable connected to the tap device card 310 and the coaxial tap 320. These stresses are considered because they can affect the contact quality between the coaxial stack and the corresponding landing pad on the PCB, or the physical integrity of the CMTL components.

[0174] Furthermore, since it is necessary to prevent the inner standoff 342 from loosening and to prevent the entire coaxial standoff 340 from rotating relative to the PCB, a solution is provided and is shown in Figure 26. In Figure 26, the outer standoff 344 has a machined outer surface with four grooves and can lock the coaxial standoff 340 at a specific angle relative to the PCB using a spring pin 302 that is securely fixed to the PCB by a compress-insert-release process.

[0175] The outer standoff 344 functions as the outer conductor of the coaxial transmission line formed within the structure of the coaxial standoff 340, and conducts the coaxial RF current of the CMTL mainly on its inner cylindrical surface due to the skin effect.

[0176] The inner standoff 342, dielectric standoff 343, and outer standoff 344 must have a coordinated structure, material, and shape that matches the mating PCB. It has been observed that the bandwidth of the CMTL increases as the average value of the inner and outer diameters of the dielectric standoff 343 decreases. When the CMTL was operated with a dielectric standoff 343 having the following characteristics, a flat bandwidth of approximately 8 GHz was obtained: (1) a hexagonal cross-section with a 5 mm square inner cavity, determined by the selection of a suitable commercially available M3 stainless steel standoff; (2) an outer diameter of 7.5 mm; and (3) made from epoxy resin or other dielectric material with a dielectric constant of approximately 3.74 that matches the PCB dielectric.

[0177] In various embodiments, the method for manufacturing dielectric standoffs involves extrusion molding with tolerance control to minimize the gap between the dielectric and the surrounding conductive surface. In examples where the dielectric is made of a softer material, the dielectric standoff 343 is cut slightly longer than the outer standoff 344, and the softness can be used to fill the cavity by utilizing the inherent compressive force generated by the inner standoff 342 to expand the soft material and fill the unwanted gap between the inner and outer standoffs.

[0178] The dielectric loss of the dielectric standoff 343 and the conductivity losses of the inner and outer standoffs 342 and 344 affect the loss and reflection along the CMTL, and these may be used to control the performance of the CMTL. It has been observed that the higher the dielectric or conductivity loss on the CMTL, the more attenuated the reflection caused by the discontinuity at the tap discontinuity. Therefore, in various embodiments, the coaxial standoffs are configured to achieve the highest possible insertion loss to maximize the predictability of the system's performance.

[0179] In some embodiments, insertion loss and reflection along the CMTL are controlled as follows: (1) by controlling the composition of the dielectric material to achieve a specific dielectric loss tangent while maintaining the dielectric dielectric constant; (2) by controlling the overall plating of the inner and outer standoffs to control the conductivity loss of the coaxial standoff; or (3) by implementing local resistive elements (Rs) 342A or 344A, as referenced in Figure 29, constructed by selective / sequential resistive plating to the standoffs, respectively, or by using resistive washers.

[0180] In another embodiment, the coaxial standoff 340 is configured as a semi-rigid structure comprising an inner standoff 342 made from a bendable tubular profile with ball-socket fastening mechanisms at both ends, an outer standoff 344 having a thick wall in the PCB contact area and a thin wall along its length, and a dielectric standoff 343 made from a flexible dielectric material.

[0181] The mounting bolt 303 serves to clamp the coaxial end 330 to the coaxial standoff 340 by engaging the mating portion of the inner standoff 342 with the inner standoff 342 using the clamping method described herein. The mounting bolt 303 is shown in Figures 26, 28, and 29 as a threaded variant. In various embodiments, the mounting bolt 303 is made of a dielectric material to avoid interference with the operation of the CMTL.

[0182] Coaxial tap for CMTL Figures 30 to 36 show various embodiments 3000, 3100, 3200, 3300, 3400, 3500, and 3600 of the coaxial tap 320. The coaxial tap 320 comprises a tap connector 322, a center hole 325, a tap pin 328A of the tap connector 322 soldered to a landing pad 328B surrounded by a gap 328C, a microvia set 328D, a tap stripline 328E, a tap resistor element 329, a tap pad 327, a via structure 326A, an inner landing pad 323A, an inner landing pad 323B, a pad 328F, a via structure 326B, a via structure 326D, a via structure 326C, an outer landing pad 324A, and an outer landing pad 324B.

[0183] The configuration of the coaxial tap 320 is based on the laminated structure 210 shown in Figure 14. Various modifications can usually be made during the manufacturing of the coaxial tap 320 based on the laminated structure 210 to accommodate local process capabilities and material availability, and such modifications may be compatible with the shape and parameters of the PCB structure described herein. Non-essential PCB layers such as plating, solder resist, or silkscreen, which are commonly used in PCB manufacturing, have been omitted for clarity.

[0184] Referring to Figure 34, the layer assignment for the copper pattern of the coaxial tap 320 will now be described. The first layer 1402 includes the inner landing pad 323A, the landing pad 328B, and the outer landing pad 324A. The second layer 1404 includes the pad 328F, the tap strip line 328E, and the tap pad 327. The fourth layer 1408 includes the inner landing pad 323B and the outer landing pad 324B.

[0185] Referring to Figure 35, in some embodiments, via structures 326A, 326B, 326C, and 326D use vias of type V1-4, with a completed hole diameter of 0.16 mm, and the landing pad diameters of the outer layers L1 1402 and L4 1408 are 0.55 mm. In some embodiments, microvia set 328D uses microvias of type V1-2, with a completed hole diameter of 0.1 mm, the landing pad diameter on layer L1 1402 is 0.35 mm, and the landing pad diameter on layer L2 1404 is 0.325 mm.

[0186] In some embodiments, via structures 326A are constructed at a pitch of approximately 0.67 mm, forming the internal conductor of the CMTL coaxial structure across the thickness of the PCB and connecting the inner landing pads 323A and 323B. The shape of via structures 326A is configured to match the shape of the inner landing pads 323A and 323B, as well as the outer shape of the inner standoff 342, to achieve an optimal fit that limits wave reflection at the contact interface. Furthermore, the plating of the inner landing pads 323A and 323B is configured to match the plating of the inner standoff 342 and its flexible conductive gasket, preventing corrosion and electromigration at the contact interface.

[0187] In some embodiments, the flexible conductive gasket used between the inner standoff 342 and the inner landing pads 323A and 323B is realized by a field molding technique. This technique involves depositing a layer of the desired material, which is cured before assembly, onto the seating surface of the standoff 342 or onto the pads on the PCB.

[0188] In some embodiments, via structures 326B are constructed with a via pitch of approximately 0.63 mm, penetrating the PCB to form the outer conductor of the CMTL coaxial structure and connecting the outer landing pads 324A and 324B. The shape of via structures 326B is configured to match the shape of the lumen of the outer landing pads 324A and 324B, as well as the internal shape of the outer standoff 344, to achieve optimal matching that minimizes wave reflection in the coaxial waveguide at their contact interfaces. The plating of the outer landing pads 324A and 324B is configured to match the plating and size of the outer standoff 344 to prevent corrosion and electromigration at the contact surfaces. Via structures 326C, connecting the outer landing pads 324A and 324B, serve to prevent RF fringe leakage from the tap strip line 328E on layer L2 1404 and are constructed with a via pitch of approximately 1 mm.

[0189] In some embodiments, the via structure 326D is made up of two vias between the outer landing pads 324A and 324B and is an integral part of the transition between the tap connector 322 and the tap strip line 328E.

[0190] In various embodiments, a tap transmission line is formed between a tap connector 322 and a tap resistive element 329, which includes a landing pad 328B, a microvia set 328D, a pad 328F, and a tap stripline 328E.

[0191] In one example, the tap strip line 328E is implemented as a 50-ohm control impedance matching the impedance of the tap connector 322 on layer L2 1404, and has a nominal width of approximately 0.125 mm and an approximate length of 2 mm. The pad 328F has a width of approximately 0.35 mm and a length of approximately 0.8 mm so that the microvia set 328D is positioned across the entire width of the landing pad 328B. The tap strip line 328E passes between the vias of the via structure 326D and through the gaps of the via structure 326B. In various examples, the length of the via strip line 328E is kept to a minimum.

[0192] In one example, the tap resistor element 329 is realized by sequentially etching a 25 ohm / □ thin film resistor embedded in the copper layer L2 1404, having a finished length of 0.63 mm and a width of 0.35 mm, with a final resistance of 45 ohms. One end is connected to the tap strip line 328E and the other end is connected to the tap pad 327. The tap pad 327 is connected to one of the vias of the via structure 326A, and in a preferred embodiment, its size is kept to a minimum.

[0193] Tap device card for CMTL One or more stacked data terminal cards 310 can be connected to the CMTL if they have a suitable coaxial structure similar to that used in the coaxial tap 320 in the printed circuit card. The implementation of the coaxial tap circuit in the tap device card 310 follows the teachings given for the coaxial tap 320, but with the following differences.

[0194] In at least one embodiment, the PCB dielectric of the tap device card 310 can be matched with the dielectric of all coaxial dielectrics used in the CMTL.

[0195] In at least one embodiment, if dielectric matching is not possible, performance loss may occur in the form of increased wave reflection along the CMTL transmission line, resulting in exaggerated peaks and troughs in the inter-tap insertion loss characteristics. This problem worsens as the number of tap device cards increases. Simulation can be used for accurate performance prediction.

[0196] In at least one embodiment, the parasitic characteristics of the via can be minimized by mounting the tap pad 327, the resistive element 329, and the tap strip line 328E on the layer closest to the layer of the tap device 311.

[0197] In at least one embodiment, a tap strip line is connected to a tap device 311 through a microvia of a via-in-pad, and this tap strip line is straddled by a pair of through vias connecting a reference ground plane used for the strip line immediately adjacent to the microvia.

[0198] In at least one embodiment, the impedance of the tap strip line matches the impedance of the tap device.

[0199] In at least one embodiment, the value of the tap resistor is determined using equation (5).

[0200] In at least one embodiment, stray RF currents in via structure 326B are prevented by connecting via structure 326B to the ground plane of tap device card 310 only in two vias that cross the stripline 328E at the exit from the coaxial structure.

[0201] In at least one embodiment, the coaxial structure zone is explicitly isolated from any wiring on the tap device card 310.

[0202] Coaxial termination for CMTL Figures 37 to 40 show various embodiments illustrating structural details 3700, 3800, 3900, and 4000 of a coaxial termination 330 according to another embodiment of the present disclosure. The coaxial termination 330 comprises a landing pad 332, a gap 333, a landing pad 334, a hole 335, a plurality of termination resistors 336, and a plurality of copper connection patterns 337.

[0203] The coaxial termination 330 is mounted on a PCB manufactured based on the laminated structure 210 of Figure 14. Landing pads 332 and 334 are constructed on layer L1 1402, and their shapes and manufacturing details are consistent with the shapes and manufacturing details given for the coaxial tap 320 and coaxial standoff 340.

[0204] In this embodiment, there are twelve terminating resistor elements 336 identically realized by sequential etching on a 25 ohm / □ thin film resistive layer embedded in the copper layer L2 1404. Each such resistor element has a finished length of 0.8 mm and a width of 0.162 mm for a total equivalent terminating resistance of 10 ohms, which is matched to the impedance of the coaxial standoff 340 and coaxial tap 320, which is determined by the individual resistance values ​​of 123 ohms and the selection of its shape and dielectric.

[0205] The radial structure of the termination resistor element 336 optimizes the frequency bandwidth of the termination alone to well over 20 GHz. The termination resistor element 336 is connected between the inner landing pad 334 and the outer landing pad 332 via a copper connection pattern 337 using type V1-2 microvias. The termination resistor element 336 is formed on the same layer L1 1402 as the landing pads 332 and 334, enabling the realization of coaxial termination 330 on a single-layer PCB including an integrated thin-film resistive layer.

[0206] Coaxial connector adapter for CMTL Figures 41 to 44 show various embodiments illustrating structural details 4100, 4200, 4300, and 4400 of another embodiment, which is a coaxial connector adapter 350 comprising a male coaxial connector 351, a female coaxial connector 352, four mounting bolts 353, a coaxial PCB adapter 354, and a coaxial standoff adapter 355.

[0207] In various embodiments, the coaxial connector adapter 350 is constructed to match the shape and impedance of other coaxial elements of a 10-ohm CMTL. The male coaxial connector 351 is of BNC type, and its dielectric and shape are adapted to match the impedance of a 10-ohm CMTL, having a coaxial cable crimp feature at one end and engaging with a corresponding female coaxial connector 352 at the other end.

[0208] The coaxial PCB adapter 354 has similar dielectric, structural, dimensional, and configuration details to the coaxial tap 352, except that it has four additional through-mounting holes that match the hole size and pattern of the female coaxial connector 352, excluding the tap resistor element 329 and related elements.

[0209] The group configuration of the inner standoff 342, dielectric standoff 343, and coaxial standoff adapter 355 follows the details described for coaxial standoff 340. The coaxial standoff adapter 355 has a shape and structure derived from the outer standoff 344, whose outer structure is oriented toward the female coaxial connector 352, with four screw holes that align with the positions of the through-holes in the female coaxial connector 352 and the coaxial PCB adapter 354, respectively, to match the corresponding shapes. The remaining structure of the coaxial standoff adapter 355 is identical to that of the outer standoff 344 to complete the adapterization. The coaxial standoff adapter 355 is pressed against the female coaxial connector 352 by four threaded bolts 353, with the coaxial PCB adapter 354 as the contact surface between them. The inner standoff 342 is screwed into the corresponding threads in the female coaxial connector 352.

[0210] The assembly, consisting of two coaxial connector adapters 350 and corresponding coaxial cables 301, is intended to improve the flexibility and reach of the CMTL.

[0211] Modeling and simulation related to CMTL Figure 45 shows a connection diagram of the coaxial tap CT4500 modeled in a manner similar to that described in Figures 28-36. In the embodiment shown in Figure 45, the coaxial tap model has a coaxial tap 320 in the center and two 7 mm long coaxial standoffs 340 on each side, with their open ends identified as ports L and R, and the open end of the tap connector 322 identified as port T.

[0212] Figure 46 shows the S-parameters for coaxial tap models, such as coaxial tap model 4500 in Figure 45. The S-parameters can be extracted and plotted using 3D EM software. Graph 4600 shows the attenuation on the y-axis 4602 as a function of frequency on the x-axis 4604.

[0213] As shown in the figure, graph 4600 shows the first plot SL-R4620, which represents the insertion loss between the left port L4505 and the right port R4510, equivalent to the longitudinal insertion loss LIL defined by equation (8) and plotted in Figure 7. Plot ST-R4605 represents the insertion loss between the left port L4505 and the right port R4510, equivalent to the transverse insertion loss TIL defined by equation (9) and shown in Figure 7. Plot ST-T4610 is the return loss at tapped port T4515, and plot SL-L4615 represents the return loss at the left port L4605.

[0214] As can be seen from Figure 46, plot SL-R4620 is low, as expected for a tap port well isolated by a line of approximately 15 mm in length and an internal resistive element (Rt) with extremely low parasitic components. This slope is mainly caused by dielectric and conductivity losses in the coaxial standoff and PCB. Plot ST-R4605 is close to the predicted TIL of approximately -13 dB at Zc = 10 ohms, as seen in Figure 7. Plot SL-L4615 has attenuation of less than -20 dB, indicating almost no reflection along the tap. Plot ST-T4610 shows very low attenuation in the low frequency range, but its performance degrades in the high frequency range. This degradation is likely due to two reasons: (1) the transition between the tap connector 322 and the tap stripline 328E, and (2) the transition of the tap stripline 328E through the dielectric zone between the outer via structure 326B and the inner via structure 326A.

[0215] The S-parameters extracted from the taps modeled in Figure 45 can be incorporated into a circuit as shown in Figure 47 to model the behavior of a CMTL assembled from 24 identical coaxial taps 320, each separated by a 14mm long coaxial standoff 340 and terminated at both ends with a characteristic impedance of Zc = 10 ohms.

[0216] Figure 48 provides plot 4800, which models the insertion loss 4802 as a function of frequency 4804. Plot (S1-24) 4805 represents the insertion loss between tap ports at each end of the CMTL to evaluate the best insertion loss. Referring to Figure 47, the tap ports at each end are the first tap port (T1) and the last tap port (T24).

[0217] Plot (S12-13)4810 shows the insertion loss between adjacent tap ports to evaluate the lowest insertion loss. Referring to Figure 48, the adjacent tap ports in the center of the CMTL are the 12th tap port (T12) and the 13th tap port (T13).

[0218] Plot (SL-L)4815 represents the return loss of the left port for evaluating the reflection along the CMTL.

[0219] Plot (SL-L)4815 reproduces similar behavior observed in PMTLs with reduced overall performance due to the removal of higher optimal resistance elements (Rs) from the tap circuit in Figure 4 (compared to a 0.5 ohm deficit in the CMTL).

[0220] The peak value in plot (SL-L)4815 is 4.9 GHz in CMTL compared to approximately 4.3 GHz observed in PMTL. This is due to the shorter tap length in CMTL. Plot (S12-13)4810 shows the mean values ​​predicted by equations (1) through (3) or Figure 7, with the low value at 4.9 GHz correlating with the high value in plot (SL-L)4815 and caused by reflections along CMTL. Plot (S1-24)4805 shows good insertion loss around -40 dB, as expected, but with a lower slope compared to PMTL.

[0221] CMTL design recommendations In at least one embodiment, the CMTL is designed and constructed using the following method, which includes evaluating the instructions given to the PMTL design and considering the lowest possible cross-sectional shape for the coaxial cable. Next, this method includes calculating its impedance and evaluating the worst-case loss at the maximum number of taps planned for the CMTL. Furthermore, this method includes constructing a coaxial cable of the intended shape and measuring its insertion loss with respect to frequency. Next, this method includes repeating the insertion loss measurements for multiple plating formulations of the internal metal structure to isolate dielectric loss from conductive loss, and optimizing the CMTL for lowest reflection by mounting the resistive elements (Rs) 342A and / or 344A shown in Figure 29 using selective resistive ring plating or resistive washers, and using a metal shielding cap on the mounting bolt 303 if the RF radiated interference from the aperture of the coaxial termination 330 is too high.

[0222] Figure 49 provides an example configuration 4900 of a multi-tap transmission line 4901 according to one embodiment. As shown in the figure, the multi-tap transmission line 4901 includes a first end 4902a and a second end 4902b. The multi-tap transmission line 4901 also includes two or more tap circuits connected to the transmission line 4901 at corresponding tap ports 4903.

[0223] In the illustrated embodiment, the transmission line 4901 includes various tap devices 4909, 4910, and 4911. In one embodiment, the tap devices include at least one of a frequency division multiplex access tap device 4909, a time division multiplex access tap device 4910, and a composite tap device 4911. Frequency division multiplex access and time division multiplex access are widely known techniques in wireless communication that can be conveniently applied to the novel transmission medium provided by the multitap transmission line 4901.

[0224] In this embodiment, terminations 4902a and 4902b have the same impedance as the characteristic impedance Zc, thereby providing the advantage of minimizing or eliminating signal reflections within the transmission line 4901. The transmission line serves as a communication medium between multiple tap devices 4911 connected to the multitap transmission line 4901 through multiple tap ports in the tap line 4904.

[0225] The tap device 4911 may be provided in the form of an RF transmitter output 4907T, an RF receiver input 4907R, an input / output shared by an RF transceiver 4907, an RF multiplexer 4905, an RF switch 4906, a data terminal 4908, a composite stream of one or more RF transceivers, a test port of a vector network analyzer VNA, a test port of a time domain reflectometry TDR analyzer, a terminator, or any other suitable RF device. In some cases, the tap device 4911 may be similar to an antenna tower that allows multiple RF devices to access the transmission medium provided by the multi-tap transmission line 4901. By applying various known techniques of wireless technology, the advantages of the multi-tap transmission line 4901 can be maximally utilized.

[0226] In at least one embodiment, the tap line 4904 can be connected to the tap line 4904 of another multi-tap transmission line such as the transmission line 4901. [[ID=⑥]]

[0227] [[ID=⑦]] [[ID=⑧]]Next, refer to FIG. 50. This figure shows a schematic diagram 5000 of a redundant multi-tap transmission line system consisting of a first multi-tap transmission line 5000A and a second multi-tap transmission line 5000B. As shown in the figure, the tap port 5003 of the first multi-tap transmission line 5000A is connected to the second multi-tap transmission line 5000B, providing redundancy to the first transmission line 500A. In this embodiment, the multi-tap transmission lines 5000A and 5000B are terminated at both ends by terminators 5002a, 5002b. [[ID=⑨]] [[ID=⑩]]

[0228] [[ID=⑪]] In some embodiments, transmission line 5001 will need to have higher availability and reliability. In these cases, it may be useful to easily deploy multiple transmission lines to increase system redundancy. When the first transmission line 5000A is severed, tap device 5011 can switch to the second transmission line 5000B using RF switch 5006. In some embodiments, the second transmission line 5000B may be useful for doubling tap device 5011. As shown, dual tap device 5012 can be used for digital switching. Tap device 5012 can be connected to tap port 5003 via tap line 5004. This may be more convenient than RF switch 5006. Thus, the second transmission line 5000B can provide the advantage of providing additional bandwidth during normal operation or functioning as a backup for the first transmission line 5000A.

[0229] Next, refer to FIG. 51. This figure shows a schematic diagram 5100 of the bridge connection of multi-tap transmission line 5101. In this embodiment, the multi-tap transmission line includes a first section 5101A and a second section 5101B. Each of sections 5101A and B terminates at first and second ends 5102 and can include at least one tap port 5103. Tap port 5103 is connected to tap device 5111 via tap line 5104. Tap device 5111 on the first section 5101A is connected or coupled to tap device 5111 on the second section 5101B to bridge-connect the first section 5101A to the second section 5101B. The bridge connection of the multi-tap transmission line can be utilized to extend the length of the transmission line for a specific frequency channel or simply bridge-connect specific data links of multiple MTLs.

[0230] Next, refer to Figure 52. This figure shows a schematic diagram 5200 of a multitap transmission line 5201 according to an exemplary embodiment. In this embodiment, the multitap transmission line 5201 is terminated at ends 5202a and 5202b. The multitap transmission line 5201 is coupled to a narrowband coupler 5213 and tap 5203 connected to a tap device 5211 at a tap line 5204. The narrowband coupler 5213 can be used when lower insertion loss is required in a particular frequency band. They may be directional, which may provide advantages in certain configurations.

[0231] Examples of multi-tap transmission line usage The multitap transmission line described in at least one of the above embodiments can be used in multiple applications or use cases in which multiple RF devices are communicated together to transmit at least one RF signal.

[0232] In at least one embodiment, the multitap transmission line is implemented for use in vehicles including, but not limited to, automobiles, trains, ships, trucks, or any other vehicles that require multiple devices connected for data transmission and reception. Figure 53 is a schematic diagram 5300 showing a multitap transmission line system 5301 adapted for an automobile use case 5314.

[0233] As shown in the figure, system 5300 consists of a first multitap transmission line 5301A and a second multitap transmission line 5301B. Each multitap transmission line 5301A and 5301B is terminated at termination point 5302. Tap devices 5312 are connected to the first and second transmission lines 5301A and 5301B at their respective tap ports 5303 through their respective tap lines 5304. Each transmission line 5301A and 5301B has a corresponding characteristic impedance value (Zc). Tap devices connected to transmission line 5301 at their corresponding tap ports 5303 have a corresponding tap impedance value (Zo). In at least one embodiment, the characteristic impedance value Zc is lower than, and in some cases considerably lower than, each tap impedance value Zo. In at least one embodiment, the first and second end impedances remain matched to the transmission lines because the tap devices 5312 are connected to the multitap transmission lines 5300.

[0234] The automotive MTLs shown in Figure 53, such as the MTL 5301A and 5301B, enable heterogeneous software-defined wireless network architectures to interconnect a wide variety of sensors and computing nodes via a shielded shared transmission medium. The MTLs in Figure 53 can be constructed as flexible printed circuit boards within adhesive tape. This offers advantages such as reduced weight and ease of design, manufacturing, and installation compared to conventional wiring systems used in automobiles. Redundant MTLs are easily installed and operated, contributing to improved system reliability. This embodiment incorporates a tap device that switches from an MTL that has lost functionality due to physical damage to an alternative MTL.

[0235] In at least one embodiment, the tap device 5312 can be a vehicle sensor, an engine control unit (ECU), a gateway, and an AI node. In a vehicle, the sensor can collect data on various parameters such as speed, temperature, and pressure. These sensors transmit signals to the engine control unit (ECU), which controls various functions such as fuel injection, ignition timing, and exhaust gas control. The AI ​​node in the vehicle is a node that incorporates artificial intelligence algorithms. These nodes can be used for a variety of purposes, such as autonomous driving, predictive maintenance, and advanced driver-assistance systems (ADAS).

[0236] Thus, these signals need to be transmitted in real time and require high frequency and high bandwidth for transmission. In at least one embodiment, the multitap transmission line has at least 24 tap devices 5312. This is typical for automotive implementations, but it will be recognized that any number of tap devices can be used.

[0237] In at least one embodiment, the multitap transmission line is constructed as a flexible printed circuit board having adhesive tape. In at least one embodiment, the multitap transmission line further includes a secondary multitap transmission line to provide redundancy for the purpose of improving vehicle safety. In at least one embodiment, the tap device switches from the primary tap transmission line 5301A to the secondary multitap transmission line 5301B using an RF switch.

[0238] Next, refer to Figure 54. This figure shows a schematic diagram of a multitap transmission line system in a branch configuration 5400 according to an exemplary embodiment. The multitap transmission line system 5400 is applicable to any remotely operated vehicle (ROV), manned or unmanned aerial vehicle (UAV / AV), or drone 5415.

[0239] As shown in the figure, system 5400 consists of four MTL branches, including the first transmission line 5401A, the second transmission line 5401B, the third transmission line 5401C, and the fourth transmission line 5401D. Each transmission line 5401A to 5401D has a first end 5402 at one end and a common node 5416 in the middle. The common node 5416 is a resistive power distributor with four ports, each port of which is connected to each transmission line 5401A to 5401D, as shown in Figure 55. Each transmission line 5401A to 5401D has the same corresponding characteristic impedance value (Zc).

[0240] Furthermore, each transmission line 5401A to 5401D has two or more tap devices 5411 connected at corresponding tap ports 5403. Each tap port 5403 has a corresponding tap impedance value (Zo), where the characteristic impedance value Zc is lower than, and in some cases considerably lower than, each tap impedance value Zo. In various embodiments, the transmission lines 5401A to 5401D are configured and optimized based on the teachings herein.

[0241] In at least one embodiment, the tap device 5411 can be an ROV sensor, an ROV engine control unit (ECU), an ROV gateway, and an ROV AI node. In the ROV, the sensors can collect data on various parameters such as airspeed, temperature, and pressure. These sensors transmit signals to the ROV engine control unit (ECU), which is responsible for controlling various functions such as battery life, takeoff, landing, and flight path. The ROV AI node in the operator is a node that incorporates artificial intelligence algorithms. These nodes can be used for various purposes such as autonomous flight, predictive maintenance, and flight path determination.

[0242] Therefore, since the ROV needs to be weight-balanced and as lightweight as possible to optimize its operation, there may be constraints on the placement of tap devices 5411 such as sensors. By implementing the multi-tap transmission line shown in Figure 54, a lightweight system can be provided that can replace cables such as Ethernet cables and coaxial cables. This also provides the advantage and possibility of strategically placing devices 5411 such as sensors to distribute weight evenly.

[0243] Referring together to Figures 54 and 55, a schematic diagram 5500 of a power distributor 5516 having the same characteristic impedance Zc as the multi-tap transmission lines 5401A to 5401D is shown in Figure 55. In the embodiments shown in Figures 54 and 55, four branches are shown. However, the power distributor 5516 may include any number of branches, such as 2, 3, 4, 5, 6...N, and therefore it can be understood that the transmission line 5400 may consist of a different number of branches corresponding to the number of branches in the power distributor 5516. In at least one embodiment, the multi-tap transmission line may be multiple branches, in which case one transmission line such as transmission line 5401A, 5401B, 5401C, or 5401D is further branched into multiple transmission lines.

[0244] In one embodiment, a second multitap transmission line can be added to the first multitap transmission line as a tap device. In one embodiment, the tap device is another multitap transmission line.

[0245] In the embodiment shown in Figure 55, a branched transmission medium is illustrated. This can be useful for drone applications and similar applications where computing nodes and sensor nodes are ideally positioned under tight weight balance, enabling interconnection with a lightweight transmission medium and switchless broadband data communication. Essentially, branched MTL makes it possible to construct a shared transmission medium for computing nodes and sensor nodes arbitrarily placed on the drone body without compromising data transmission performance, while meeting the static and dynamic balance requirements of the drone.

[0246] Now, turn to FIG. 56. This figure shows a schematic diagram 5600 of a multi-tap transmission line system applied to a use case of a server rack. Reference numeral 5617 indicates a server rack according to an exemplary embodiment. FIG. 57 is a schematic diagram 5700 of a multi-tap transmission line that details the connection portion 5622 of FIG. 56.

[0247] The multi-tap transmission lines in FIGS. 56 and 57 enable interconnecting servers within a server rack without using a data switch or cables that may cause cable management problems.

[0248] As shown in FIGS. 56 and 57, the system 5600 includes a multi-tap transmission line 5700 connected to a plurality of tap lines 5704. The tap lines 5704 are connected to the transmission line 5700 at the reinforcement attachment point 5720. The tap lines 5704 are connected at the other end to an RF connector 5718 on the front panel of a server 5719, where the server 5719 is a tap device in this case.

[0249] In this embodiment, the multi-tap transmission line is implemented as a flexible printed circuit board attached to the rack frame 5617 by the upper right member 5721 of the rack frame 5617. In some embodiments, the multi-tap transmission line is constructed of a rigid PCB with a shorter length or is horizontally mounted within the rack between servers.

[0250] Thus, all servers 5719 can simultaneously broadcast data to all other servers via a shared interference-free transmission medium 5700. Each tap provides ultra-wideband access to the MTL 5700, enabling fast and easy data transmission across the entire transmission line.

[0251] Figure 58 is a schematic diagram 5800 of a simplified three-layer AI network. Reference numeral 5823 indicates a layer of compute nodes 5824. Figure 59 shows that each compute node 5824 is equipped with an integrated tap device 5911. Reference numeral 5825 indicates a data link connecting compute nodes 5824 in adjacent layers 5823. Reference numeral 5826 indicates a mesh network of compute nodes 5824 organized in layer 5823 of compute nodes.

[0252] Figure 59 shows the configuration 5900 of the AI ​​network in Figure 58, which is composed of multi-tap transmission lines 5901. As shown in Figure 59, three layers 5923, similar to layer 5823 in Figure 58, are connected by two transmission lines 5901, with the first transmission line 5901 located between the first two layers 5923 and the second transmission line 5901 located between the second and third layers 5923.

[0253] Each transmission line 5901 is terminated at each end by an endpoint 5902. Each transmission line 5901 has multiple tap ports 5903, and corresponding tap lines 5904 connect the compute node 5924 to the transmission line 5901 at the corresponding tap ports 5903. In this illustrated embodiment, each compute node 5924 has two integrated tap devices 5911. In some other examples, each compute node may be provided with a different number of integrated tap devices.

[0254] In the illustrated embodiment, each multitap transmission line 5901 has a corresponding characteristic impedance value (Zc), and each tap port has a corresponding tap impedance value (Zo). In at least one embodiment, the characteristic impedance value Zc is lower than, and in some cases considerably lower than, each tap impedance value Zo. The illustrated MTL system 5900 efficiently resolves communication between successive computing layers 5923 of a machine learning neural network by using RF data broadcasting on different radio frequency channels. Each connected computing node 5924 can instantly and directly share data with all connected nodes 5924 via the multitap transmission line 5901, which acts as a broadband transmission medium.

[0255] In this embodiment, the MTL can be mounted within a rigid printed circuit board (PCB), which is common in data server motherboard designs, or as a separate flexible printed circuit board if it is necessary to reinforce an existing rigid PCB structure. In some other cases, the illustrated MTL can be mounted on a silicon substrate for chips, a chiplet, or an interposer, among other mounting options.

[0256] While the present invention has been described and illustrated with reference to its preferred embodiments, those skilled in the art will recognize that various modifications can be made in form and detail without departing from the spirit and scope of the invention as defined by the appended claims. The applicant's teachings described herein are presented in conjunction with various embodiments for illustrative purposes, but are not intended to be limited to such embodiments. Rather, the applicant's teachings described and illustrated herein encompass a variety of alternatives, modifications, and equivalents, without departing from the general scope of the embodiments defined by the appended claims.

[0257] item: 1. Disclosed herein is a broadband high-frequency transmission line that connects multiple high-frequency terminals using waveguides and taps in a single unit to construct a data network. The transmission line includes a left termination, a right termination, and multiple tap circuits. Each tap circuit includes a left port, a right port, a tap port, a left transmission line, a right transmission line, a left resistive element, a right resistive element, and a tap resistive element. In the transmission line, the left and right resistive elements are substantially characterized by having substantially identical resistance values ​​Rs, and the tap resistive element is substantially characterized by having a resistance value Rt. In the transmission line, the left and right transmission lines each have substantially identical characteristic impedance values ​​Zc. The left transmission line is connected between the left port and the left resistive element, the left resistive element is connected between the left transmission line and the right resistive element, the right resistive element is connected between the left resistive element and the right transmission line, the right transmission line is connected between the right resistive element and the right port, and the tap resistive element is connected at one end to a common connection point between the left and right resistive elements and at the other end to the tap port. In a transmission line, a tap port is connected to an external high-frequency terminal with an impedance value Zo measured at the tap port. The left and right terminations are configured as resistive elements and are substantially characterized by their resistance value Zc. Multiple tap circuits are connected such that the left port of the first tap circuit is connected to the left termination, the right port of the last tap circuit is connected to the right termination, and each of the other right ports of the tap circuit is connected to the single left port of that tap circuit.

[0258] 2. In another section, the impedance of the resistive elements in the transmission line and its tap circuit is optimized for power transmission.

[0259] 3. In another section, the termination, resistive elements, and transmission lines are substantially constructed as planar waveguides.

[0260] 4. In another section, the termination, left and right resistive elements, and transmission lines are substantially constructed as a coaxial waveguide.

[0261] 5.1 items are provided with multi-tap transmission lines.

[0262] 6. In another section, a multi-tap transmission line comprises a first end and at least one second end, the transmission line having a corresponding characteristic impedance value (Zc), the first end having a corresponding first end impedance which is the same as the characteristic impedance, at least one second end having a corresponding at least one second end impedance which is the same as the characteristic impedance, at least two tap circuits are connected to the transmission line, each tap circuit having a tap port, each tap port having a corresponding tap impedance value (Zo), and the characteristic impedance value Zc is lower than each tap impedance value Zo.

[0263] 7. In another section, the multi-tap transmission line further comprises, for each tap circuit, a first resistive element corresponding to the first port of the tap circuit and having a corresponding first resistance value, a second resistive element corresponding to the second port of the tap circuit and having a second resistance value, a corresponding tap device connected to the corresponding tap port, and a tap resistive element corresponding to the tap port and having a tap resistance value (Rt), wherein the first and second resistance values ​​are substantially equal to the series resistance value (Rs), and the first resistive element, the second resistive element, and the tap resistive element are connected at a connection point in a T-shape configuration.

[0264] 8. In another section, the tap device is selected from the group consisting of an output RF transmitter, an input RF receiver, an RF transceiver that serves as both input and output, an RC transceiver, multiple RF transceivers, a test port of a vector network analyzer (VNA), a test port of a time-domain reflectivity measurement (TDR) analyzer, a tap point on another multi-tap transmission line, any RF device, and a termination.

[0265] 9. In another section, the first and second end impedances remain matched to the transmission line when the tap device is connected to a multi-tap transmission line.

[0266] 10. In another section, the transmission line includes a distributor configuration, where at least one second end includes two second ends.

[0267] 11. In another section, the multi-tap transmission line is mounted as a rigid printed circuit board.

[0268] 12. In another section, the multi-tap transmission lines are mounted as individual flexible printed circuit boards.

[0269] 13. In another section, the multi-tap transmission line is constructed as a flexible printed circuit board with adhesive tape.

[0270] 14. In another section, the multi-tap transmission line is constructed in a branched configuration.

[0271] 15. In another instance, a multitap transmission line operates with at least one tap device disconnected, short-circuited, or damaged. In such an embodiment, the multitap transmission line operates with the remaining tap devices.

[0272] 16. In another section, the first and second resistive elements have a corresponding series resistance of approximately 0 ohms.

[0273] 17. A method for optimizing a multi-tap transmission line is provided for one item.

[0274] 18. In another section, this method includes the steps of determining an optimal characteristic impedance value (Zc) for each corresponding tap impedance value (Zo) and for the total number of tap ports in the transmission line, and determining a series resistance value (Rs) and a tap resistance value (Rt) based on the optimal characteristic impedance value (Zc) such that the loss between the first tap circuit and the last tap circuit is minimized.

[0275] 19. In another section, the step of determining the optimal characteristic impedance value (Zc) is to select a candidate impedance value from a range of values ​​between 0 and the termination impedance value; and for each candidate impedance value: to determine the worst-case insertion loss between the first tap circuit and the last tap circuit based on the candidate impedance value and the tap impedance value corresponding to the tap port, wherein the worst-case insertion loss is determined based on the determination of the longitudinal and transverse insertion losses according to the following formula: TTLN[dB]=TIL(1)+LIL(2)+LIL(3)+...+LIL(j)+...LIL(N-1)+TIL(N); where LIL is the longitudinal insertion loss value determined according to LIL(j)=20LOG10(1-Zc / 2Zo(j)), where j is a range of values ​​indicating the tap index from 2 to (N-1), and N is the total number of tap ports; where TIL is the lateral insertion loss value determined according to TIL(j)=10LOG10(Zc / 4Zo(j)), where j is 1 or N; and the formula includes the step of determining the optimal characteristic impedance value (Zc) based on candidate impedance values ​​that minimize the worst-case insertion loss.

[0276] 20. In another section, the series resistance value (Rs) is: TIFF2026513982000016.tif11114

[0277] It is determined according to the formula, where Zo(j) is the tap impedance value of tap port j, j is a range of values ​​indicating the tap index ranging from 1 to N, N represents the total number of tap ports, and Zc is the optimal characteristic impedance value.

[0278] 21. In another section, the tap resistance value (Rt) is: TIFF2026513982000017.tif11114

[0279] It is determined according to the formula, where Zo(j) is the tap impedance value of tap port j, j is a range of values ​​indicating the tap index ranging from 1 to N, N represents the total number of tap ports, and Zc is the optimal characteristic impedance value.

[0280] 22. In another item, the method further includes the step of selecting an alternative characteristic impedance value (Zc) from a range between -30% and +30% of the optimal characteristic impedance value.

[0281] 23. In another section, the step of determining the optimal characteristic impedance value (Zc) is as a function of the candidate impedance values: This is performed using graph analysis, which involves plotting the loss function following TTLN(Zc)=TIL(1)+LIL(2)+LIL(3)+...+LIL(j)+...LIL(N-1)+TIL(N) and selecting the optimal characteristic impedance value based on the candidate impedance value corresponding to the minimum value of the loss function.

[0282] 24. In one item, a multi-tap transmission line for use in an automobile vehicle is provided.

[0283] 25. In another item, a multi-tap transmission line comprises a first end and at least one second end, the transmission line having a corresponding characteristic impedance value (Zc), the first end having a corresponding first end impedance which is the same as the characteristic impedance, at least one second end having a corresponding at least one second end impedance which is the same as the characteristic impedance, at least two tap circuits are connected to the transmission line, each tap circuit having a tap port, each tap port having a corresponding tap impedance value (Zo), and the characteristic impedance value Zc is lower than each tap impedance value Zo.

[0284] 26. In another section, the multi-tap transmission line further comprises, for each tap circuit, a first resistive element corresponding to the first port of the tap circuit and having a corresponding first resistance value, a second resistive element corresponding to the second port of the tap circuit and having a second resistance value, a corresponding tap device connected to the corresponding tap port, and a tap resistive element corresponding to the tap port and having a tap resistance value (Rt), wherein the first and second resistance values ​​are substantially equal to the series resistance value (Rs), and the first resistive element, the second resistive element, and the tap resistive element are connected at a connection point in a T-shape configuration.

[0285] 27. In another section, a multitap transmission line further comprises at least 24 tap devices.

[0286] 28. In another section, the tap device is selected from a group consisting of vehicle sensors, engine control units (ECUs), gateways, and AI nodes.

[0287] 29. In another section, the multi-tap transmission line is constructed as a flexible printed circuit board with adhesive tape.

[0288] 30. In another section, a multitap transmission line further comprises a secondary multitap transmission line to provide redundancy.

[0289] 31. In another section, the tap device switches from a multitap transmission line to a secondary multitap transmission line.

[0290] 32. In one item, a multi-tap transmission line is provided for use with a remotely operated vehicle (ROV).

[0291] 33. In another section, the tap device is selected from a group consisting of ROV sensors, ROV engine control units (ECUs), ROV gateways, and ROV AI nodes.

[0292] 34. In another section, the multi-tap transmission line is constructed in a branched configuration.

[0293] 35. In another section, a multitap transmission line is equipped with a resistive power distributor for branching the multitap transmission line into multiple lines.

[0294] 36. In one item, a multi-tap transmission cable is provided for use in a server rack.

[0295] 37. In another section, the tap device is a server.

[0296] 38. In one item, a multitap transmission line is provided for use with multiple processor chips in an inter-chip configuration.

[0297] 39. In another section, a multitap transmission line is located outside of multiple processor chips and connected to nodes within multiple processor chips.

[0298] 40. In another section, the multi-tap transmission line is mounted as a rigid printed circuit board.

[0299] 41. In another section, the multi-tap transmission lines are mounted as individual flexible printed circuit boards.

[0300] 42. In another section, the multitap transmission line is mounted on at least one of the chip silicon substrate, chiplet, and interposer. [Explanation of Symbols]

[0301] 100, 200, 500 multi-tap transmission cable 101 Wi-Fi Transceiver 102 Wireless Network 103 Propagation medium 210 Laminated structure 211 mounting holes 222 Full board 223 Tap Connector 225 Nut 230D1 End Pad 230D2 Termination Microvia Set 230D3 Termination resistor element 230E1 Tap Resistor Element 230E2 Tap Pad 230E3 Tap Strip Line 230E4 Tap Micro Via Set 232 transmission striplines 233 Tap Pin Pad 237, 238 Ground Plane 239A, 239B, 239C via structure 241 Backplane 242 slot connector 243 Differential pin pairs 300-pronged multi-tap transmission cable 301 Coaxial Cable 302 Spring Pin 303 Mounting bolts 310 Tap Device Card 311, 411, 511 Tap Devices 320 Coaxial Tap 330 coax termination 340 Coaxial Standoff 342 Inside Standoff 343 Dielectric Standoff 344 Outside Standoff 350 Coaxial Connector Adapter 400, 2350 tap circuit 401a First transmission line 401b Second transmission line 402 Terminus 403, 503, 2115, 4515 Tap Ports 405 Signal 416 Power divider 430a, 2105, 4505 Left Port 430b, 2110, 4510 Right Port 435a First resistive element 435b Second resistive element 436 Tap Resistor Element 504 Tap Line 534, 536 Resistor elements 1402 First copper layer 1404 Second copper layer 1406 Third copper layer 1408 Fourth copper layer 1410 First Core Layer 1412 Insulating layer 1414 Second core layer 1420 Through-hole via type 1422 Micro Beer / Beer Type 2510 Tap Resistor Element Rt 2515 p-pin 2520 n-pin

Claims

1. It is a multi-tap transmission line, A first end and at least one second end, Equipped with, The transmission line has a corresponding characteristic impedance value (Zc), The first end has a corresponding first end impedance, the first end impedance being the same as the characteristic impedance. The at least one second end has a corresponding at least one second end impedance, and the corresponding at least one second end impedance is the same as the characteristic impedance. At least two tap circuits are connected to the transmission line, each tap circuit having a tap port, and each tap port having a corresponding tap impedance value (Zo), The characteristic impedance value Zc is lower than the individual tap impedance values ​​Zo in the multi-tap transmission line.

2. For each tap circuit, A first resistor element corresponding to the first port of the tap circuit and having a corresponding first resistance value, A second resistive element having a second resistance value, corresponding to the second port of the tap circuit, A corresponding tap device connected to the corresponding tap port, A tap resistor element corresponding to the aforementioned tap port and having a tap resistance value (Rt), Furthermore, The first and second resistance values ​​are substantially equal to the series resistance value (Rs), The multi-tap transmission line according to claim 1, wherein the first resistive element, the second resistive element, and the tap resistive element are connected at a connection point in a T-shape configuration.

3. The multitap transmission line according to claim 1 or 2, wherein the tap device is selected from the group consisting of an output RF transmitter, an input RF receiver, an RF transceiver that serves as both input and output, an RC transceiver, a plurality of RF transceivers, a test port of a vector network analyzer (VNA), a test port of a time-domain reflectivity measurement (TDR) analyzer, a tap point of another multitap transmission line, any RF device, and a termination.

4. The multitap transmission line according to any one of claims 1 to 3, wherein the first end impedance and the second end impedance maintain a state that is matched to the transmission line when the tap device is connected to the multitap transmission line.

5. The multi-tap transmission line according to any one of claims 1 to 4, wherein the transmission line includes a distributor configuration, and the at least one second end includes two second ends.

6. The multitap transmission line according to claim 1, wherein the multitap transmission line is mounted as a rigid printed circuit board.

7. The multi-tap transmission line according to claim 1, wherein the multi-tap transmission line is mounted as an individual flexible printed circuit board.

8. The multi-tap transmission line according to claim 1, wherein the multi-tap transmission line is constructed as a flexible printed circuit board having adhesive tape.

9. The multi-tap transmission line according to any one of claims 1 to 8, wherein the multi-tap transmission line is constructed in a branch configuration.

10. The multitap transmission line according to any one of claims 1 to 9, wherein the multitap transmission line operates with at least one of the tap devices disconnected, short-circuited, or damaged.

11. The multi-tap transmission line according to any one of claims 1 to 10, wherein the first and second resistive elements have corresponding series resistance values ​​of about 0 ohms.

12. A method for optimizing a multitap transmission line, wherein the multitap transmission line is A first end and at least one second end, Equipped with, The transmission line has a corresponding characteristic impedance value (Zc), The first end has a corresponding first end impedance, the first end impedance being the same as the characteristic impedance. The at least one second end has a corresponding at least one second end impedance, and the corresponding at least one second end impedance is the same as the characteristic impedance. At least two tap circuits are connected to the transmission line, each tap circuit having a tap port, and each tap port having a corresponding tap impedance value (Zo), The aforementioned multi-tap transmission line, for each tap circuit, A first resistor element corresponding to the first port of the tap circuit and having a corresponding first resistance value, A second resistive element having a second resistance value, corresponding to the second port of the tap circuit, A corresponding tap device connected to the corresponding tap port, A tap resistor element corresponding to the aforementioned tap port and having a tap resistance value (Rt), Furthermore, The first and second resistance values ​​are substantially equal to the series resistance value (Rs), The first resistive element, the second resistive element, and the tapped resistive element are connected at a connection point in a T-shape configuration. For each corresponding tap impedance value (Zo), and for the total number of tap ports in the transmission line, The steps include determining the optimal characteristic impedance value (Zc), The steps include determining the series resistance value (Rs) and the tap resistance value (Rt) based on the optimal characteristic impedance value (Zc) such that the loss between the first tap circuit and the last tap circuit is minimized, A method that includes this.

13. The step of determining the optimal characteristic impedance value (Zc) is as follows: A step of selecting a candidate impedance value from a range of values ​​between 0 and the termination impedance value, For each candidate impedance value: A step of determining the worst-case insertion loss between a first tap circuit and a last tap circuit based on the candidate impedance value and the tap impedance value corresponding to the tap port, wherein the worst-case insertion loss is determined based on the determination of the longitudinal insertion loss and transverse insertion loss according to the following formula: TTLN [dB] = TIL (1) + LIL (2) + LIL (3) + .. .. .. +LIL(j)+ .. .. .. LIL(N-1)+TIL(N); In the formula, LIL is, LIL(j)=20LOG10(1-Zc / 2Zo(j)) This is the longitudinal insertion loss value determined according to the following: In the formula, j is a range of values ​​representing the tap index, from 2 to (N-1), and N represents the total number of tap ports. During the ceremony, TIL is, TIL(j)=10LOG10(Zc / 4Zo(j)) This is the lateral insertion loss value determined according to the following: In the formula, j is 1 or N, and the process is as follows: A step of determining the optimal characteristic impedance value (Zc) based on the candidate impedance value that minimizes the worst-case insertion loss, A method for optimizing a multitap transmission line according to claim 12, including the method described in claim 12.

14. The aforementioned series resistance value (Rs) is It is decided according to, A method for optimizing a multi-tap transmission line according to claim 13, wherein Zo(j) is the tap impedance value of tap port j, j is a range of values ​​representing the tap index ranging from 1 to N, N represents the total number of tap ports, and Zc is the optimal characteristic impedance value.

15. The tap resistance value (Rt) is, It is decided according to, A method for optimizing a multi-tap transmission line according to claim 14, wherein Zo(j) is the tap impedance value of tap port j, j is a range of values ​​representing the tap index ranging from 1 to N, N represents the total number of tap ports, and Zc is the optimal characteristic impedance value.

16. A method for optimizing a multitap transmission line according to claim 12, further comprising the step of selecting an alternative characteristic impedance value (Zc) from a range between -30% and +30% of the optimal characteristic impedance value.

17. The step of determining the optimal characteristic impedance value (Zc) is performed as a function of the candidate impedance values: TTLN(Zc)=TIL(1)+LIL(2)+LIL(3)+ .. .. .. +LIL(j)+ .. .. .. LIL(N-1)+TIL(N) A method for optimizing a multitap transmission line according to claim 12, which is performed by graph analysis, by plotting a loss function according to; and selecting the optimal characteristic impedance value based on the candidate impedance value corresponding to the minimum value of the loss function.

18. A method for optimizing a multitap transmission line according to any one of claims 12 to 17, wherein the first and second resistive elements have corresponding series resistance values ​​of about 0 ohms.

19. A multi-tap transmission line for use in automobile vehicles, A first end and at least one second end, Equipped with, The transmission line has a corresponding characteristic impedance value (Zc), The first end has a corresponding first end impedance, the first end impedance being the same as the characteristic impedance. The at least one second end has a corresponding at least one second end impedance, and the corresponding at least one second end impedance is the same as the characteristic impedance. At least two tap circuits are connected to the transmission line, each tap circuit having a tap port, and each tap port having a corresponding tap impedance value (Zo), The characteristic impedance value Zc is lower than the individual tap impedance values ​​Zo in the multi-tap transmission line.

20. For each tap circuit, A first resistor element corresponding to the first port of the tap circuit and having a corresponding first resistance value, A second resistive element having a second resistance value, corresponding to the second port of the tap circuit, A corresponding tap device connected to the corresponding tap port, A tap resistor element corresponding to the aforementioned tap port and having a tap resistance value (Rt), Furthermore, The first and second resistance values ​​are substantially equal to the series resistance value (Rs), The multi-tap transmission line according to claim 19, wherein the first resistive element, the second resistive element, and the tap resistive element are connected at a connection point in a T-shape configuration.

21. A multitap transmission line according to claim 19, comprising at least 24 tap devices.

22. The multi-tap transmission line according to claim 21, wherein the tap device is selected from the group consisting of a vehicle sensor, an engine control unit (ECU), a gateway, and an AI node.

23. The multi-tap transmission line according to any one of claims 19 to 22, wherein the multi-tap transmission line is constructed as a flexible printed circuit board having adhesive tape.

24. A multitap transmission line according to any one of claims 19 to 23, further comprising a secondary multitap transmission line to provide redundancy.

25. The multitap transmission line according to claim 24, wherein the tapping device switches from the multitap transmission line to the secondary multitap transmission line.

26. A multi-tap transmission line for use in remotely operated vehicles (ROVs), A first end and at least one second end, Equipped with, The transmission line has a corresponding characteristic impedance value (Zc), The first end has a corresponding first end impedance, the first end impedance being the same as the characteristic impedance. The at least one second end has a corresponding at least one second end impedance, and the corresponding at least one second end impedance is the same as the characteristic impedance. At least two tap circuits are connected to the transmission line, each tap circuit having a tap port, and each tap port having a corresponding tap impedance value (Zo), The characteristic impedance value Zc is lower than the individual tap impedance values ​​Zo in the multi-tap transmission line.

27. For each tap circuit, A first resistor element corresponding to the first port of the tap circuit and having a corresponding first resistance value, A second resistive element having a second resistance value, corresponding to the second port of the tap circuit, A corresponding tap device connected to the corresponding tap port, A tap resistor element corresponding to the aforementioned tap port and having a tap resistance value (Rt), Furthermore, The first and second resistance values ​​are substantially equal to the series resistance value (Rs), The multi-tap transmission line according to claim 26, wherein the first resistive element, the second resistive element, and the tap resistive element are connected at a connection point in a T-shape configuration.

28. The multi-tap transmission line according to claim 27, wherein the tap device is selected from the group consisting of an ROV sensor, an ROV engine control unit (ECU), an ROV gateway, and an ROV AI node.

29. The multitap transmission line according to claim 27 or 28, wherein the multitap transmission line is constructed in a branch configuration.

30. A multitap transmission line according to any one of claims 27 to 29, further comprising a resistive power distributor for branching the multitap transmission line into multiple lines.

31. A multi-tap transmission cable for use in server racks, A first end and at least one second end, Equipped with, The transmission line has a corresponding characteristic impedance value (Zc), The first end has a corresponding first end impedance, the first end impedance being the same as the characteristic impedance. The at least one second end has a corresponding at least one second end impedance, and the corresponding at least one second end impedance is the same as the characteristic impedance. At least two tap circuits are connected to the transmission line at corresponding tap ports, each tap port having a corresponding tap impedance value (Zo), The characteristic impedance value Zc is lower than the individual tap impedance values ​​Zo in the multi-tap transmission line.

32. For each tap circuit, A first resistor element corresponding to the first port of the tap circuit and having a corresponding first resistance value, A second resistive element having a second resistance value, corresponding to the second port of the tap circuit, A corresponding tap device connected to the corresponding tap port, A tap resistor element corresponding to the aforementioned tap port and having a tap resistance value (Rt), Furthermore, The first and second resistance values ​​are substantially equal to the series resistance value (Rs), The multi-tap transmission line according to claim 31, wherein the first resistive element, the second resistive element, and the tap resistive element are connected at a connection point in a T-shape configuration.

33. The multi-tap transmission line according to claim 32, wherein the tap device is a server.

34. A multitap transmission line for use with multiple processor chips in an inter-chip configuration, which is located outside the multiple processor chips and connected to nodes within the multiple processor chips, A first end and at least one second end, Equipped with, The transmission line has a corresponding characteristic impedance value (Zc), The first end has a corresponding first end impedance, the first end impedance being the same as the characteristic impedance. The at least one second end has a corresponding at least one second end impedance, and the corresponding at least one second end impedance is the same as the characteristic impedance. At least two tap circuits are connected to the transmission line, Each tap circuit is equipped with a tap port, and each tap port has a corresponding tap impedance value (Zo). The characteristic impedance value Zc is lower than the individual tap impedance values ​​Zo in the multi-tap transmission line.

35. For each tap circuit, A first resistor element corresponding to the first port of the tap circuit and having a corresponding first resistance value, A second resistive element having a second resistance value, corresponding to the second port of the tap circuit, A corresponding tap device connected to the corresponding tap port, A tap resistor element corresponding to the aforementioned tap port and having a tap resistance value (Rt), Furthermore, The first and second resistance values ​​are substantially equal to the series resistance value (Rs), The multi-tap transmission line according to claim 34, wherein the first resistive element, the second resistive element, and the tap resistive element are connected at a connection point in a T-shape configuration.

36. The multi-tap transmission line according to claim 34, wherein the multi-tap transmission line is mounted as a rigid printed circuit board.

37. The multi-tap transmission line according to claim 34, wherein the multi-tap transmission line is mounted as an individual flexible printed circuit board.

38. The multitap transmission line according to claim 34, wherein the multitap transmission line is mounted on at least one of a silicon substrate for chips, a chiplet, and an interposer.

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