Understanding the Maximum Speed that can be Transmitted over a Cable

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I am trying to source a FFC/FPC cable for USB3.0 (+5gbps). This brought me to the question of signal transmission. I'm somewhat of a beginner in this topic. I know that you should match impedance on your PCB with your connector/cable to minimize reflections.



I was wondering how to tell how fast of a signal you can transmit over a wire. Specifically what kind of cable parameters affect transmission speed?
Any help is appreciated.










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  • Quick question: are you more interested in the physical properties of the wires or are you more interested in the particularities of fast transmission protocols.
    – Simon Marcoux
    2 days ago










  • physical properties
    – Nick
    2 days ago






  • 2




    don't forget to accept an answer once all your questions are answered.
    – Simon Marcoux
    2 days ago










  • When you increase the frequency the em wave tends to free propagation (the same of the aerials). This is the reason of using wave guides or coaxial wires (that are the same thing) for microvawaves propagation. The external conductor constrains the wave to follow the path
    – Gianluca Conte
    yesterday
















up vote
8
down vote

favorite
1












I am trying to source a FFC/FPC cable for USB3.0 (+5gbps). This brought me to the question of signal transmission. I'm somewhat of a beginner in this topic. I know that you should match impedance on your PCB with your connector/cable to minimize reflections.



I was wondering how to tell how fast of a signal you can transmit over a wire. Specifically what kind of cable parameters affect transmission speed?
Any help is appreciated.










share|improve this question







New contributor




Nick is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.



















  • Quick question: are you more interested in the physical properties of the wires or are you more interested in the particularities of fast transmission protocols.
    – Simon Marcoux
    2 days ago










  • physical properties
    – Nick
    2 days ago






  • 2




    don't forget to accept an answer once all your questions are answered.
    – Simon Marcoux
    2 days ago










  • When you increase the frequency the em wave tends to free propagation (the same of the aerials). This is the reason of using wave guides or coaxial wires (that are the same thing) for microvawaves propagation. The external conductor constrains the wave to follow the path
    – Gianluca Conte
    yesterday












up vote
8
down vote

favorite
1









up vote
8
down vote

favorite
1






1





I am trying to source a FFC/FPC cable for USB3.0 (+5gbps). This brought me to the question of signal transmission. I'm somewhat of a beginner in this topic. I know that you should match impedance on your PCB with your connector/cable to minimize reflections.



I was wondering how to tell how fast of a signal you can transmit over a wire. Specifically what kind of cable parameters affect transmission speed?
Any help is appreciated.










share|improve this question







New contributor




Nick is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











I am trying to source a FFC/FPC cable for USB3.0 (+5gbps). This brought me to the question of signal transmission. I'm somewhat of a beginner in this topic. I know that you should match impedance on your PCB with your connector/cable to minimize reflections.



I was wondering how to tell how fast of a signal you can transmit over a wire. Specifically what kind of cable parameters affect transmission speed?
Any help is appreciated.







signal-integrity high-speed ffc fpc






share|improve this question







New contributor




Nick is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











share|improve this question







New contributor




Nick is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









share|improve this question




share|improve this question






New contributor




Nick is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









asked 2 days ago









Nick

485




485




New contributor




Nick is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.





New contributor





Nick is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.






Nick is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











  • Quick question: are you more interested in the physical properties of the wires or are you more interested in the particularities of fast transmission protocols.
    – Simon Marcoux
    2 days ago










  • physical properties
    – Nick
    2 days ago






  • 2




    don't forget to accept an answer once all your questions are answered.
    – Simon Marcoux
    2 days ago










  • When you increase the frequency the em wave tends to free propagation (the same of the aerials). This is the reason of using wave guides or coaxial wires (that are the same thing) for microvawaves propagation. The external conductor constrains the wave to follow the path
    – Gianluca Conte
    yesterday
















  • Quick question: are you more interested in the physical properties of the wires or are you more interested in the particularities of fast transmission protocols.
    – Simon Marcoux
    2 days ago










  • physical properties
    – Nick
    2 days ago






  • 2




    don't forget to accept an answer once all your questions are answered.
    – Simon Marcoux
    2 days ago










  • When you increase the frequency the em wave tends to free propagation (the same of the aerials). This is the reason of using wave guides or coaxial wires (that are the same thing) for microvawaves propagation. The external conductor constrains the wave to follow the path
    – Gianluca Conte
    yesterday















Quick question: are you more interested in the physical properties of the wires or are you more interested in the particularities of fast transmission protocols.
– Simon Marcoux
2 days ago




Quick question: are you more interested in the physical properties of the wires or are you more interested in the particularities of fast transmission protocols.
– Simon Marcoux
2 days ago












physical properties
– Nick
2 days ago




physical properties
– Nick
2 days ago




2




2




don't forget to accept an answer once all your questions are answered.
– Simon Marcoux
2 days ago




don't forget to accept an answer once all your questions are answered.
– Simon Marcoux
2 days ago












When you increase the frequency the em wave tends to free propagation (the same of the aerials). This is the reason of using wave guides or coaxial wires (that are the same thing) for microvawaves propagation. The external conductor constrains the wave to follow the path
– Gianluca Conte
yesterday




When you increase the frequency the em wave tends to free propagation (the same of the aerials). This is the reason of using wave guides or coaxial wires (that are the same thing) for microvawaves propagation. The external conductor constrains the wave to follow the path
– Gianluca Conte
yesterday










4 Answers
4






active

oldest

votes

















up vote
22
down vote



accepted










The maximum frequency is mostly related to the frequency-dependent loss characteristics of the cable. Eventually you get to a frequency where you simply don't get enough signal at the other end to use.



  • Resistive losses in the conductors (including skin effect)

  • Dielectric losses in the insulating materials

  • Radiation losses if the cable is not fully shielded

All of these tend to increase with frequency.



This is why we generally switch to other technologies at very high frequencies: waveguides for microwave radio equipment and optical fibers for high-speed data.






share|improve this answer






















  • I would upvote but I do not have enough rep. Thanks for your response!
    – Nick
    2 days ago










  • Is the signal loss due to resistance in the wire?
    – Nick
    2 days ago






  • 1




    Partly resistance in the conductors, and also dielectric losses. There are also radiation losses if the cable is not fully shielded. All of these tend to increase with frequency.
    – Dave Tweed♦
    2 days ago






  • 2




    The signal imposes a time-varying electric field across the dielectrics used in the cables. Charges within those dielectrics move around in response to those fields, and sometimes they don't conserve all of the energy used in that motion. For example, if the material is at all piezoelectric, some of the energy goes into distorting its physical shape, which eventually turns into randomized heat.
    – Dave Tweed♦
    2 days ago






  • 2




    Don't forget about dielectric dispersion (different phase velocities at different signal frequencies). This technically isn't loss but causes distortion.
    – Captainj2001
    2 days ago

















up vote
7
down vote













You can't just "source" FFC/FPC cables for USB 3.x. These cables (and corresponding connectors) are not qualified for USB 3.x channels. The cables for USB 3.0 have to meet many more requirements than just a wire parameters and not just having certain differential impedance.



To use non-standard (not within USB defined configuration) cables you will need to run all USB cable qualification tests on your own, ensure limits on insertion loss, NEXT/FEXT crosstalk, differential impedance across mated connectors, etc. etc., if you want your product to work with any reasonable degree of reliability.



To run your own qualification you will need at least a 8-16GHz oscilloscope and a 20-GHz TDR (Time-domain reflectometer) instrument, plus make a dedicated break-out fixture to access signals in correct way. The list of electrical requirements for USB 3.0 transmission lines is given in the following USB-IF document. Although the document is mostly for qualification of standard cables and mating connectors, appendix to the document shows the general electrical requirements to meet.






share|improve this answer






















  • You will need to learn to use SMA connectors.
    – analogsystemsrf
    yesterday










  • @analogsystemsrf, didn't you mean "OP will need to learn SMA connectors"? And not forget to buy a 5/16 properly pre-set torque wrench for them... just $216.26 from Pasternack for example... :-)
    – Ale..chenski
    yesterday










  • @analogsystemsrf Have you seen a USB 3 connector on a motherboard? They're pin headers.
    – user71659
    yesterday










  • @user71659, Have you seen any USB 3.0 test fixture? usb.org/developers/estoreinfo/SuperSpeedTestTopologies.pdf
    – Ale..chenski
    yesterday











  • @Ale..chenski That's because you want the fixture to be easily de-embedable. It's not necessary for the normal operation of USB 3.0.
    – user71659
    yesterday

















up vote
4
down vote













The frequency that can be used inside a wire is highly dependant on the skin effect. Simply put, the bigger the wire, the lower the frequency it can carry without having signal loss caused by an increase of its impedance.



At low frequency, the signal will be equally distributed through most of the wire, with a higher frequency, the signal will be predominantly distributed around the perimeter of the wire (the ''skin'').



The wires that allow the best characteristics will always be really small and with multiple conductors to reduce the skin effect. Despite this, the higher you go, the more loss you will get. Then the protocol steps in and will increase the voltage, use twisted differential pairs and push the boundaries to the maximum until you need to switch to a different transfer technology altogether.






share|improve this answer



























    up vote
    0
    down vote














    I was wondering how to tell how fast of a signal you can transmit over a wire. Specifically what kind of cable parameters affect transmission speed? Any help is appreciated.




    The Comcast XB6 Cable Modem will do over 1.5 Gbps using your standard cablevision coax. The speed is limited to your last-mile speed, otherwise it would be higher.



    PCIe 5.0 does ~4GB/s (or x16 @ ~128GB/s). A x1 connection, the smallest PCIe connection, has one lane made up of four wires. It carries one bit per cycle in each direction.



    So 2 pieces of wire can do ~2GB/s in practice, in theory you could squeeze some more out of it. For plain wire coax cable is the fastest because it's shielded. Along with shielding length is the next most important factor, with shortest distances (inches) being the best.






    share|improve this answer




















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      4 Answers
      4






      active

      oldest

      votes








      4 Answers
      4






      active

      oldest

      votes









      active

      oldest

      votes






      active

      oldest

      votes








      up vote
      22
      down vote



      accepted










      The maximum frequency is mostly related to the frequency-dependent loss characteristics of the cable. Eventually you get to a frequency where you simply don't get enough signal at the other end to use.



      • Resistive losses in the conductors (including skin effect)

      • Dielectric losses in the insulating materials

      • Radiation losses if the cable is not fully shielded

      All of these tend to increase with frequency.



      This is why we generally switch to other technologies at very high frequencies: waveguides for microwave radio equipment and optical fibers for high-speed data.






      share|improve this answer






















      • I would upvote but I do not have enough rep. Thanks for your response!
        – Nick
        2 days ago










      • Is the signal loss due to resistance in the wire?
        – Nick
        2 days ago






      • 1




        Partly resistance in the conductors, and also dielectric losses. There are also radiation losses if the cable is not fully shielded. All of these tend to increase with frequency.
        – Dave Tweed♦
        2 days ago






      • 2




        The signal imposes a time-varying electric field across the dielectrics used in the cables. Charges within those dielectrics move around in response to those fields, and sometimes they don't conserve all of the energy used in that motion. For example, if the material is at all piezoelectric, some of the energy goes into distorting its physical shape, which eventually turns into randomized heat.
        – Dave Tweed♦
        2 days ago






      • 2




        Don't forget about dielectric dispersion (different phase velocities at different signal frequencies). This technically isn't loss but causes distortion.
        – Captainj2001
        2 days ago














      up vote
      22
      down vote



      accepted










      The maximum frequency is mostly related to the frequency-dependent loss characteristics of the cable. Eventually you get to a frequency where you simply don't get enough signal at the other end to use.



      • Resistive losses in the conductors (including skin effect)

      • Dielectric losses in the insulating materials

      • Radiation losses if the cable is not fully shielded

      All of these tend to increase with frequency.



      This is why we generally switch to other technologies at very high frequencies: waveguides for microwave radio equipment and optical fibers for high-speed data.






      share|improve this answer






















      • I would upvote but I do not have enough rep. Thanks for your response!
        – Nick
        2 days ago










      • Is the signal loss due to resistance in the wire?
        – Nick
        2 days ago






      • 1




        Partly resistance in the conductors, and also dielectric losses. There are also radiation losses if the cable is not fully shielded. All of these tend to increase with frequency.
        – Dave Tweed♦
        2 days ago






      • 2




        The signal imposes a time-varying electric field across the dielectrics used in the cables. Charges within those dielectrics move around in response to those fields, and sometimes they don't conserve all of the energy used in that motion. For example, if the material is at all piezoelectric, some of the energy goes into distorting its physical shape, which eventually turns into randomized heat.
        – Dave Tweed♦
        2 days ago






      • 2




        Don't forget about dielectric dispersion (different phase velocities at different signal frequencies). This technically isn't loss but causes distortion.
        – Captainj2001
        2 days ago












      up vote
      22
      down vote



      accepted







      up vote
      22
      down vote



      accepted






      The maximum frequency is mostly related to the frequency-dependent loss characteristics of the cable. Eventually you get to a frequency where you simply don't get enough signal at the other end to use.



      • Resistive losses in the conductors (including skin effect)

      • Dielectric losses in the insulating materials

      • Radiation losses if the cable is not fully shielded

      All of these tend to increase with frequency.



      This is why we generally switch to other technologies at very high frequencies: waveguides for microwave radio equipment and optical fibers for high-speed data.






      share|improve this answer














      The maximum frequency is mostly related to the frequency-dependent loss characteristics of the cable. Eventually you get to a frequency where you simply don't get enough signal at the other end to use.



      • Resistive losses in the conductors (including skin effect)

      • Dielectric losses in the insulating materials

      • Radiation losses if the cable is not fully shielded

      All of these tend to increase with frequency.



      This is why we generally switch to other technologies at very high frequencies: waveguides for microwave radio equipment and optical fibers for high-speed data.







      share|improve this answer














      share|improve this answer



      share|improve this answer








      edited 2 days ago

























      answered 2 days ago









      Dave Tweed♦

      108k9129230




      108k9129230











      • I would upvote but I do not have enough rep. Thanks for your response!
        – Nick
        2 days ago










      • Is the signal loss due to resistance in the wire?
        – Nick
        2 days ago






      • 1




        Partly resistance in the conductors, and also dielectric losses. There are also radiation losses if the cable is not fully shielded. All of these tend to increase with frequency.
        – Dave Tweed♦
        2 days ago






      • 2




        The signal imposes a time-varying electric field across the dielectrics used in the cables. Charges within those dielectrics move around in response to those fields, and sometimes they don't conserve all of the energy used in that motion. For example, if the material is at all piezoelectric, some of the energy goes into distorting its physical shape, which eventually turns into randomized heat.
        – Dave Tweed♦
        2 days ago






      • 2




        Don't forget about dielectric dispersion (different phase velocities at different signal frequencies). This technically isn't loss but causes distortion.
        – Captainj2001
        2 days ago
















      • I would upvote but I do not have enough rep. Thanks for your response!
        – Nick
        2 days ago










      • Is the signal loss due to resistance in the wire?
        – Nick
        2 days ago






      • 1




        Partly resistance in the conductors, and also dielectric losses. There are also radiation losses if the cable is not fully shielded. All of these tend to increase with frequency.
        – Dave Tweed♦
        2 days ago






      • 2




        The signal imposes a time-varying electric field across the dielectrics used in the cables. Charges within those dielectrics move around in response to those fields, and sometimes they don't conserve all of the energy used in that motion. For example, if the material is at all piezoelectric, some of the energy goes into distorting its physical shape, which eventually turns into randomized heat.
        – Dave Tweed♦
        2 days ago






      • 2




        Don't forget about dielectric dispersion (different phase velocities at different signal frequencies). This technically isn't loss but causes distortion.
        – Captainj2001
        2 days ago















      I would upvote but I do not have enough rep. Thanks for your response!
      – Nick
      2 days ago




      I would upvote but I do not have enough rep. Thanks for your response!
      – Nick
      2 days ago












      Is the signal loss due to resistance in the wire?
      – Nick
      2 days ago




      Is the signal loss due to resistance in the wire?
      – Nick
      2 days ago




      1




      1




      Partly resistance in the conductors, and also dielectric losses. There are also radiation losses if the cable is not fully shielded. All of these tend to increase with frequency.
      – Dave Tweed♦
      2 days ago




      Partly resistance in the conductors, and also dielectric losses. There are also radiation losses if the cable is not fully shielded. All of these tend to increase with frequency.
      – Dave Tweed♦
      2 days ago




      2




      2




      The signal imposes a time-varying electric field across the dielectrics used in the cables. Charges within those dielectrics move around in response to those fields, and sometimes they don't conserve all of the energy used in that motion. For example, if the material is at all piezoelectric, some of the energy goes into distorting its physical shape, which eventually turns into randomized heat.
      – Dave Tweed♦
      2 days ago




      The signal imposes a time-varying electric field across the dielectrics used in the cables. Charges within those dielectrics move around in response to those fields, and sometimes they don't conserve all of the energy used in that motion. For example, if the material is at all piezoelectric, some of the energy goes into distorting its physical shape, which eventually turns into randomized heat.
      – Dave Tweed♦
      2 days ago




      2




      2




      Don't forget about dielectric dispersion (different phase velocities at different signal frequencies). This technically isn't loss but causes distortion.
      – Captainj2001
      2 days ago




      Don't forget about dielectric dispersion (different phase velocities at different signal frequencies). This technically isn't loss but causes distortion.
      – Captainj2001
      2 days ago












      up vote
      7
      down vote













      You can't just "source" FFC/FPC cables for USB 3.x. These cables (and corresponding connectors) are not qualified for USB 3.x channels. The cables for USB 3.0 have to meet many more requirements than just a wire parameters and not just having certain differential impedance.



      To use non-standard (not within USB defined configuration) cables you will need to run all USB cable qualification tests on your own, ensure limits on insertion loss, NEXT/FEXT crosstalk, differential impedance across mated connectors, etc. etc., if you want your product to work with any reasonable degree of reliability.



      To run your own qualification you will need at least a 8-16GHz oscilloscope and a 20-GHz TDR (Time-domain reflectometer) instrument, plus make a dedicated break-out fixture to access signals in correct way. The list of electrical requirements for USB 3.0 transmission lines is given in the following USB-IF document. Although the document is mostly for qualification of standard cables and mating connectors, appendix to the document shows the general electrical requirements to meet.






      share|improve this answer






















      • You will need to learn to use SMA connectors.
        – analogsystemsrf
        yesterday










      • @analogsystemsrf, didn't you mean "OP will need to learn SMA connectors"? And not forget to buy a 5/16 properly pre-set torque wrench for them... just $216.26 from Pasternack for example... :-)
        – Ale..chenski
        yesterday










      • @analogsystemsrf Have you seen a USB 3 connector on a motherboard? They're pin headers.
        – user71659
        yesterday










      • @user71659, Have you seen any USB 3.0 test fixture? usb.org/developers/estoreinfo/SuperSpeedTestTopologies.pdf
        – Ale..chenski
        yesterday











      • @Ale..chenski That's because you want the fixture to be easily de-embedable. It's not necessary for the normal operation of USB 3.0.
        – user71659
        yesterday














      up vote
      7
      down vote













      You can't just "source" FFC/FPC cables for USB 3.x. These cables (and corresponding connectors) are not qualified for USB 3.x channels. The cables for USB 3.0 have to meet many more requirements than just a wire parameters and not just having certain differential impedance.



      To use non-standard (not within USB defined configuration) cables you will need to run all USB cable qualification tests on your own, ensure limits on insertion loss, NEXT/FEXT crosstalk, differential impedance across mated connectors, etc. etc., if you want your product to work with any reasonable degree of reliability.



      To run your own qualification you will need at least a 8-16GHz oscilloscope and a 20-GHz TDR (Time-domain reflectometer) instrument, plus make a dedicated break-out fixture to access signals in correct way. The list of electrical requirements for USB 3.0 transmission lines is given in the following USB-IF document. Although the document is mostly for qualification of standard cables and mating connectors, appendix to the document shows the general electrical requirements to meet.






      share|improve this answer






















      • You will need to learn to use SMA connectors.
        – analogsystemsrf
        yesterday










      • @analogsystemsrf, didn't you mean "OP will need to learn SMA connectors"? And not forget to buy a 5/16 properly pre-set torque wrench for them... just $216.26 from Pasternack for example... :-)
        – Ale..chenski
        yesterday










      • @analogsystemsrf Have you seen a USB 3 connector on a motherboard? They're pin headers.
        – user71659
        yesterday










      • @user71659, Have you seen any USB 3.0 test fixture? usb.org/developers/estoreinfo/SuperSpeedTestTopologies.pdf
        – Ale..chenski
        yesterday











      • @Ale..chenski That's because you want the fixture to be easily de-embedable. It's not necessary for the normal operation of USB 3.0.
        – user71659
        yesterday












      up vote
      7
      down vote










      up vote
      7
      down vote









      You can't just "source" FFC/FPC cables for USB 3.x. These cables (and corresponding connectors) are not qualified for USB 3.x channels. The cables for USB 3.0 have to meet many more requirements than just a wire parameters and not just having certain differential impedance.



      To use non-standard (not within USB defined configuration) cables you will need to run all USB cable qualification tests on your own, ensure limits on insertion loss, NEXT/FEXT crosstalk, differential impedance across mated connectors, etc. etc., if you want your product to work with any reasonable degree of reliability.



      To run your own qualification you will need at least a 8-16GHz oscilloscope and a 20-GHz TDR (Time-domain reflectometer) instrument, plus make a dedicated break-out fixture to access signals in correct way. The list of electrical requirements for USB 3.0 transmission lines is given in the following USB-IF document. Although the document is mostly for qualification of standard cables and mating connectors, appendix to the document shows the general electrical requirements to meet.






      share|improve this answer














      You can't just "source" FFC/FPC cables for USB 3.x. These cables (and corresponding connectors) are not qualified for USB 3.x channels. The cables for USB 3.0 have to meet many more requirements than just a wire parameters and not just having certain differential impedance.



      To use non-standard (not within USB defined configuration) cables you will need to run all USB cable qualification tests on your own, ensure limits on insertion loss, NEXT/FEXT crosstalk, differential impedance across mated connectors, etc. etc., if you want your product to work with any reasonable degree of reliability.



      To run your own qualification you will need at least a 8-16GHz oscilloscope and a 20-GHz TDR (Time-domain reflectometer) instrument, plus make a dedicated break-out fixture to access signals in correct way. The list of electrical requirements for USB 3.0 transmission lines is given in the following USB-IF document. Although the document is mostly for qualification of standard cables and mating connectors, appendix to the document shows the general electrical requirements to meet.







      share|improve this answer














      share|improve this answer



      share|improve this answer








      edited 2 days ago









      Harry Svensson

      6,50732245




      6,50732245










      answered 2 days ago









      Ale..chenski

      23.2k11756




      23.2k11756











      • You will need to learn to use SMA connectors.
        – analogsystemsrf
        yesterday










      • @analogsystemsrf, didn't you mean "OP will need to learn SMA connectors"? And not forget to buy a 5/16 properly pre-set torque wrench for them... just $216.26 from Pasternack for example... :-)
        – Ale..chenski
        yesterday










      • @analogsystemsrf Have you seen a USB 3 connector on a motherboard? They're pin headers.
        – user71659
        yesterday










      • @user71659, Have you seen any USB 3.0 test fixture? usb.org/developers/estoreinfo/SuperSpeedTestTopologies.pdf
        – Ale..chenski
        yesterday











      • @Ale..chenski That's because you want the fixture to be easily de-embedable. It's not necessary for the normal operation of USB 3.0.
        – user71659
        yesterday
















      • You will need to learn to use SMA connectors.
        – analogsystemsrf
        yesterday










      • @analogsystemsrf, didn't you mean "OP will need to learn SMA connectors"? And not forget to buy a 5/16 properly pre-set torque wrench for them... just $216.26 from Pasternack for example... :-)
        – Ale..chenski
        yesterday










      • @analogsystemsrf Have you seen a USB 3 connector on a motherboard? They're pin headers.
        – user71659
        yesterday










      • @user71659, Have you seen any USB 3.0 test fixture? usb.org/developers/estoreinfo/SuperSpeedTestTopologies.pdf
        – Ale..chenski
        yesterday











      • @Ale..chenski That's because you want the fixture to be easily de-embedable. It's not necessary for the normal operation of USB 3.0.
        – user71659
        yesterday















      You will need to learn to use SMA connectors.
      – analogsystemsrf
      yesterday




      You will need to learn to use SMA connectors.
      – analogsystemsrf
      yesterday












      @analogsystemsrf, didn't you mean "OP will need to learn SMA connectors"? And not forget to buy a 5/16 properly pre-set torque wrench for them... just $216.26 from Pasternack for example... :-)
      – Ale..chenski
      yesterday




      @analogsystemsrf, didn't you mean "OP will need to learn SMA connectors"? And not forget to buy a 5/16 properly pre-set torque wrench for them... just $216.26 from Pasternack for example... :-)
      – Ale..chenski
      yesterday












      @analogsystemsrf Have you seen a USB 3 connector on a motherboard? They're pin headers.
      – user71659
      yesterday




      @analogsystemsrf Have you seen a USB 3 connector on a motherboard? They're pin headers.
      – user71659
      yesterday












      @user71659, Have you seen any USB 3.0 test fixture? usb.org/developers/estoreinfo/SuperSpeedTestTopologies.pdf
      – Ale..chenski
      yesterday





      @user71659, Have you seen any USB 3.0 test fixture? usb.org/developers/estoreinfo/SuperSpeedTestTopologies.pdf
      – Ale..chenski
      yesterday













      @Ale..chenski That's because you want the fixture to be easily de-embedable. It's not necessary for the normal operation of USB 3.0.
      – user71659
      yesterday




      @Ale..chenski That's because you want the fixture to be easily de-embedable. It's not necessary for the normal operation of USB 3.0.
      – user71659
      yesterday










      up vote
      4
      down vote













      The frequency that can be used inside a wire is highly dependant on the skin effect. Simply put, the bigger the wire, the lower the frequency it can carry without having signal loss caused by an increase of its impedance.



      At low frequency, the signal will be equally distributed through most of the wire, with a higher frequency, the signal will be predominantly distributed around the perimeter of the wire (the ''skin'').



      The wires that allow the best characteristics will always be really small and with multiple conductors to reduce the skin effect. Despite this, the higher you go, the more loss you will get. Then the protocol steps in and will increase the voltage, use twisted differential pairs and push the boundaries to the maximum until you need to switch to a different transfer technology altogether.






      share|improve this answer
























        up vote
        4
        down vote













        The frequency that can be used inside a wire is highly dependant on the skin effect. Simply put, the bigger the wire, the lower the frequency it can carry without having signal loss caused by an increase of its impedance.



        At low frequency, the signal will be equally distributed through most of the wire, with a higher frequency, the signal will be predominantly distributed around the perimeter of the wire (the ''skin'').



        The wires that allow the best characteristics will always be really small and with multiple conductors to reduce the skin effect. Despite this, the higher you go, the more loss you will get. Then the protocol steps in and will increase the voltage, use twisted differential pairs and push the boundaries to the maximum until you need to switch to a different transfer technology altogether.






        share|improve this answer






















          up vote
          4
          down vote










          up vote
          4
          down vote









          The frequency that can be used inside a wire is highly dependant on the skin effect. Simply put, the bigger the wire, the lower the frequency it can carry without having signal loss caused by an increase of its impedance.



          At low frequency, the signal will be equally distributed through most of the wire, with a higher frequency, the signal will be predominantly distributed around the perimeter of the wire (the ''skin'').



          The wires that allow the best characteristics will always be really small and with multiple conductors to reduce the skin effect. Despite this, the higher you go, the more loss you will get. Then the protocol steps in and will increase the voltage, use twisted differential pairs and push the boundaries to the maximum until you need to switch to a different transfer technology altogether.






          share|improve this answer












          The frequency that can be used inside a wire is highly dependant on the skin effect. Simply put, the bigger the wire, the lower the frequency it can carry without having signal loss caused by an increase of its impedance.



          At low frequency, the signal will be equally distributed through most of the wire, with a higher frequency, the signal will be predominantly distributed around the perimeter of the wire (the ''skin'').



          The wires that allow the best characteristics will always be really small and with multiple conductors to reduce the skin effect. Despite this, the higher you go, the more loss you will get. Then the protocol steps in and will increase the voltage, use twisted differential pairs and push the boundaries to the maximum until you need to switch to a different transfer technology altogether.







          share|improve this answer












          share|improve this answer



          share|improve this answer










          answered 2 days ago









          Simon Marcoux

          962217




          962217




















              up vote
              0
              down vote














              I was wondering how to tell how fast of a signal you can transmit over a wire. Specifically what kind of cable parameters affect transmission speed? Any help is appreciated.




              The Comcast XB6 Cable Modem will do over 1.5 Gbps using your standard cablevision coax. The speed is limited to your last-mile speed, otherwise it would be higher.



              PCIe 5.0 does ~4GB/s (or x16 @ ~128GB/s). A x1 connection, the smallest PCIe connection, has one lane made up of four wires. It carries one bit per cycle in each direction.



              So 2 pieces of wire can do ~2GB/s in practice, in theory you could squeeze some more out of it. For plain wire coax cable is the fastest because it's shielded. Along with shielding length is the next most important factor, with shortest distances (inches) being the best.






              share|improve this answer
























                up vote
                0
                down vote














                I was wondering how to tell how fast of a signal you can transmit over a wire. Specifically what kind of cable parameters affect transmission speed? Any help is appreciated.




                The Comcast XB6 Cable Modem will do over 1.5 Gbps using your standard cablevision coax. The speed is limited to your last-mile speed, otherwise it would be higher.



                PCIe 5.0 does ~4GB/s (or x16 @ ~128GB/s). A x1 connection, the smallest PCIe connection, has one lane made up of four wires. It carries one bit per cycle in each direction.



                So 2 pieces of wire can do ~2GB/s in practice, in theory you could squeeze some more out of it. For plain wire coax cable is the fastest because it's shielded. Along with shielding length is the next most important factor, with shortest distances (inches) being the best.






                share|improve this answer






















                  up vote
                  0
                  down vote










                  up vote
                  0
                  down vote










                  I was wondering how to tell how fast of a signal you can transmit over a wire. Specifically what kind of cable parameters affect transmission speed? Any help is appreciated.




                  The Comcast XB6 Cable Modem will do over 1.5 Gbps using your standard cablevision coax. The speed is limited to your last-mile speed, otherwise it would be higher.



                  PCIe 5.0 does ~4GB/s (or x16 @ ~128GB/s). A x1 connection, the smallest PCIe connection, has one lane made up of four wires. It carries one bit per cycle in each direction.



                  So 2 pieces of wire can do ~2GB/s in practice, in theory you could squeeze some more out of it. For plain wire coax cable is the fastest because it's shielded. Along with shielding length is the next most important factor, with shortest distances (inches) being the best.






                  share|improve this answer













                  I was wondering how to tell how fast of a signal you can transmit over a wire. Specifically what kind of cable parameters affect transmission speed? Any help is appreciated.




                  The Comcast XB6 Cable Modem will do over 1.5 Gbps using your standard cablevision coax. The speed is limited to your last-mile speed, otherwise it would be higher.



                  PCIe 5.0 does ~4GB/s (or x16 @ ~128GB/s). A x1 connection, the smallest PCIe connection, has one lane made up of four wires. It carries one bit per cycle in each direction.



                  So 2 pieces of wire can do ~2GB/s in practice, in theory you could squeeze some more out of it. For plain wire coax cable is the fastest because it's shielded. Along with shielding length is the next most important factor, with shortest distances (inches) being the best.







                  share|improve this answer












                  share|improve this answer



                  share|improve this answer










                  answered yesterday









                  Rob

                  22917




                  22917




















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